Star type
g M4.5 V
Distance from Earth
g 18.61 ly
Star Service No.
g NA
Age
g 4.2 billion years
Diameter/Mass/Temp (xSol)
g NA; 16%; NA
Brightness (xSol)
g 0.0378%
Metallicity
g NA
Comparison to Sol
g See chart (similar to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g 0.019 A.U.s with an average orbital period of 1.87853 Earth days
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g J. Herschel 5173 / HR 7703 / HD 191408 AB: 4.5 ly
g CD-46 11540 / Gl 674: 6.7 ly
g Delta Pavonis: 7.7 ly
g MLO 4: 9.7 ly
g Epsilon Indi: 9.9 ly
g Lacaille 8760 / AX Mic: 8.4 ly
Map locating star system
g See stellar map
Location in Earth sky
g In constellation Corona Australis
Other names
g GJ 3379; Gliese 754; HD 36395; HIP 25878; LHS 60; LTT 17897; Wolf 1453; YPC 4505
Sci-fi mentions
g NA
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Friday, August 31, 2007
Thursday, August 30, 2007
GJ 205
Star type
g M1.5 Vn
Distance from Earth
g 18.56 ly
Star Service No.
g NA
Age
g NA
Radius/Mass/Temp (xSol)
g 70%; 50%-65%; NA
Brightness (xSol)
g 2.05%
Metallicity
g Compared to its photosphere the corona appears to be metal deficient
Comparison to Sol
g See chart (similar to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See stellar map (Listed as “L347-14”)
Location in Earth sky
g In constellation Orion
Other names
g Luyten 347-14
g LHS 60
g BD-03 1123
g CSV 6182
g HIP 25878
g Wolf 1450
Sci-fi mentions
g NA
g M1.5 Vn
Distance from Earth
g 18.56 ly
Star Service No.
g NA
Age
g NA
Radius/Mass/Temp (xSol)
g 70%; 50%-65%; NA
Brightness (xSol)
g 2.05%
Metallicity
g Compared to its photosphere the corona appears to be metal deficient
Comparison to Sol
g See chart (similar to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See stellar map (Listed as “L347-14”)
Location in Earth sky
g In constellation Orion
Other names
g Luyten 347-14
g LHS 60
g BD-03 1123
g CSV 6182
g HIP 25878
g Wolf 1450
Sci-fi mentions
g NA
Wednesday, August 29, 2007
GJ 251
Star type
g dM4-M3
Distance from Earth
g 18.15 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 33%; NA
Brightness (xSol)
g 0.299%
Metallicity
g NA
Comparison to Sol
g See chart (similar in size to Proxima)
Picture of star
g NA
Star system features
g See research paper “The 40-Year Intensive Sproul Plate Series on Wolf 294”
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g DX Cancri: 8.2 ly
g Luyten’s Star: 9.4 ly
g Procyon: 9.9 ly
Map locating star system
g See stellar map (listed as “Wolf 294”)
Location in Earth sky
g In constellation Gemini
Other names
g Wolf 294
g HD 265866
g HIP 33226
g LHS 1879
g AC+33 25644
Sci-fi mentions
g NA
g dM4-M3
Distance from Earth
g 18.15 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 33%; NA
Brightness (xSol)
g 0.299%
Metallicity
g NA
Comparison to Sol
g See chart (similar in size to Proxima)
Picture of star
g NA
Star system features
g See research paper “The 40-Year Intensive Sproul Plate Series on Wolf 294”
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g DX Cancri: 8.2 ly
g Luyten’s Star: 9.4 ly
g Procyon: 9.9 ly
Map locating star system
g See stellar map (listed as “Wolf 294”)
Location in Earth sky
g In constellation Gemini
Other names
g Wolf 294
g HD 265866
g HIP 33226
g LHS 1879
g AC+33 25644
Sci-fi mentions
g NA
Tuesday, August 28, 2007
Stein 2051 AB
Star type
g A: M4.0
g B: DC5 (white dwarf)
Distance from Earth
g 18.05 ly
Star Service No.
g NA
Age
g A: 4.1 by
g B: 3.1 by
Radius/Mass/Temp (xSol)
g A: NA; 22%; NA
g B: 1.15%; 48%-67%; NA
Brightness (xSol)
g A: 0.1%
g B: 0.03%
Metallicity
g A: NA
g B: No lines deeper than 5% of spectrum ("continuous")
Comparison to Sol
g A: See chart (similar to Proxima)
g B: See chart
Picture of star
g A: NA
g B: NA
Star system features
g A dark companion, probably a brown dwarf, may orbit Star A at distance of 4.8 AU
g See research paper “Triple system Stein 2051”
Known planets
g A is orbited by a vast asteroid field, over 2AU deep. Its white dwarf companion star orbits beyond the limits of the field at a distance of 39 AU.
Habitable zone
g NA
Orbital map
g Stars separted by 39 AUs
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g Eta Cassiopeiae 2: 9.2 ly
Map locating star system
g See stellar map
Location in Earth sky
g In constellation Camelopardalis
Other names
g A-B:GJ 169.1 AB
g A-B: Stn 2051 AB
g A: AC+58 25001
g A: AC+58 25002
g B: LHS 26
g B: G 175-34
g B: LHS 27
Sci-fi mentions
g NA
g A: M4.0
g B: DC5 (white dwarf)
Distance from Earth
g 18.05 ly
Star Service No.
g NA
Age
g A: 4.1 by
g B: 3.1 by
Radius/Mass/Temp (xSol)
g A: NA; 22%; NA
g B: 1.15%; 48%-67%; NA
Brightness (xSol)
g A: 0.1%
g B: 0.03%
Metallicity
g A: NA
g B: No lines deeper than 5% of spectrum ("continuous")
Comparison to Sol
g A: See chart (similar to Proxima)
g B: See chart
Picture of star
g A: NA
g B: NA
Star system features
g A dark companion, probably a brown dwarf, may orbit Star A at distance of 4.8 AU
g See research paper “Triple system Stein 2051”
Known planets
g A is orbited by a vast asteroid field, over 2AU deep. Its white dwarf companion star orbits beyond the limits of the field at a distance of 39 AU.
Habitable zone
g NA
Orbital map
g Stars separted by 39 AUs
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g Eta Cassiopeiae 2: 9.2 ly
Map locating star system
g See stellar map
Location in Earth sky
g In constellation Camelopardalis
Other names
g A-B:GJ 169.1 AB
g A-B: Stn 2051 AB
g A: AC+58 25001
g A: AC+58 25002
g B: LHS 26
g B: G 175-34
g B: LHS 27
Sci-fi mentions
g NA
Monday, August 27, 2007
Wolf 498 AB
Star type
g A: M4V
g B: M7V
Distance from Earth
g 17.91 ly
Star Service No.
g NA
Age
g A: NA
g B: NA
Diameter/Mass/Temp (xSol)
g A: NA; 44%; 3662 K
g B: NA; 9.5%; NA
Brightness (xSol)
g A: 0.039% (UV flare star)
g B: 0.024%
Metallicity
g A: Its metallicity is lower than the sun, with a relationship between the content of iron and hydrogen about half that in the Sun.
g B: NA
Comparison to Sol
g See illustration
Picture of star
g A: NA
g B: NA
Star system features
g Stars separated by 73 AU
Known planets
g A: NA
g B: NA
Habitable zone
Wolf 498 isn't very likely to host Earth-like life. First, both stars in the system are very small and dim compared to Sol. So, for a planet in Wolf 498 to receive enough heat from either star to ensure water on its surface wasn't frozen, it would be so close to its sun that it would be tidally locked, meaning it wouldn't spin on its axis. One side always would face the sun and be so hot that water would boil; the other side always would face away from the sun and be so cold that water would be frozen. Liquid water and air temperatures would only be Earth-comfortable in a very narrow band from pole to pole that is in perpetual twilight between the sun-side and the night-side. In addition, the star's metallicity level is about half of that of our sun, meaning there is very little carbon, oxygen, and nitrogen compared to hydrogen and helium there, making the formation of life improbable. This is not to say that life couldn't exist on Wolf 498, but if it does it would be extremely alien compared to that on Earth, or in a science fiction scenario would be "colonists" or people on an outpost who were limited entirely to artifical habitats.
g A: NA
g B: NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g Wolf 424: 7.2ly
g VanMaanen’s Star: 7.4 ly
g Tau Ceti: 8.11 ly
g Lacaille 9352: 9.4 ly
Map locating star system
g NA
Location in Earth sky
g In constellation Bootes (nearest star in that constellation to Earth)
Other names
g Gliese 526; GJ 1005; L 722-22 AB; HD 119850; Lalande 25372; Hip 1242; HIP 67155; LHS 1047 AB; G 158-50 AB
Sci-fi mentions
g NA
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g A: M4V
g B: M7V
Distance from Earth
g 17.91 ly
Star Service No.
g NA
Age
g A: NA
g B: NA
Diameter/Mass/Temp (xSol)
g A: NA; 44%; 3662 K
g B: NA; 9.5%; NA
Brightness (xSol)
g A: 0.039% (UV flare star)
g B: 0.024%
Metallicity
g A: Its metallicity is lower than the sun, with a relationship between the content of iron and hydrogen about half that in the Sun.
g B: NA
Comparison to Sol
g See illustration
Picture of star
g A: NA
g B: NA
Star system features
g Stars separated by 73 AU
Known planets
g A: NA
g B: NA
Habitable zone
Wolf 498 isn't very likely to host Earth-like life. First, both stars in the system are very small and dim compared to Sol. So, for a planet in Wolf 498 to receive enough heat from either star to ensure water on its surface wasn't frozen, it would be so close to its sun that it would be tidally locked, meaning it wouldn't spin on its axis. One side always would face the sun and be so hot that water would boil; the other side always would face away from the sun and be so cold that water would be frozen. Liquid water and air temperatures would only be Earth-comfortable in a very narrow band from pole to pole that is in perpetual twilight between the sun-side and the night-side. In addition, the star's metallicity level is about half of that of our sun, meaning there is very little carbon, oxygen, and nitrogen compared to hydrogen and helium there, making the formation of life improbable. This is not to say that life couldn't exist on Wolf 498, but if it does it would be extremely alien compared to that on Earth, or in a science fiction scenario would be "colonists" or people on an outpost who were limited entirely to artifical habitats.
g A: NA
g B: NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g Wolf 424: 7.2ly
g VanMaanen’s Star: 7.4 ly
g Tau Ceti: 8.11 ly
g Lacaille 9352: 9.4 ly
Map locating star system
g NA
Location in Earth sky
g In constellation Bootes (nearest star in that constellation to Earth)
Other names
g Gliese 526; GJ 1005; L 722-22 AB; HD 119850; Lalande 25372; Hip 1242; HIP 67155; LHS 1047 AB; G 158-50 AB
Sci-fi mentions
g NA
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Sunday, August 26, 2007
LP 816-060
Star type
g M4.5
Distance from Earth
g 17.9 y
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 19%; NA
Brightness (xSol)
g NA
Metallicity
g NA
Comparison to Sol
g See chart (star is similar to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See stellar map (listed as “LP 816-60”)
Location in Earth sky
g In constellation Capricornus
Other names
g Gliese X2; HIP 103039
Sci-fi mentions
g NA
g M4.5
Distance from Earth
g 17.9 y
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 19%; NA
Brightness (xSol)
g NA
Metallicity
g NA
Comparison to Sol
g See chart (star is similar to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See stellar map (listed as “LP 816-60”)
Location in Earth sky
g In constellation Capricornus
Other names
g Gliese X2; HIP 103039
Sci-fi mentions
g NA
Saturday, August 25, 2007
LHS 1723
Star type
g M4.5 V
Distance from Earth
g 17.7 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g 33%; 16%; NA
Brightness (xSol)
g 1%
Metallicity
g NA
Comparison to Sol
g See illustration (similar to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See map (listed as "LP 656-38”)
Location in Earth sky
g In constellation Eridanus
Other names
g LP 656-38
g GJ 3323
Sci-fi mentions
g NA
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g M4.5 V
Distance from Earth
g 17.7 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g 33%; 16%; NA
Brightness (xSol)
g 1%
Metallicity
g NA
Comparison to Sol
g See illustration (similar to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See map (listed as "LP 656-38”)
Location in Earth sky
g In constellation Eridanus
Other names
g LP 656-38
g GJ 3323
Sci-fi mentions
g NA
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Friday, August 24, 2007
LP 010-066
Star type
g M1.5
Distance from Earth
g 17.7 ly
Star Service No.
g NA
Age
g NA
Radius/Mass/Temp (xSol)
g 49.3%; 50.2%; NA
Brightness (xSol)
g 1.1%
Metallicity
g NA
Comparison to Sol
g See chart (similar to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g NA
Location in Earth sky
g NA
Other names
g GJ 526
g HD 119850
Sci-fi mentions
g NA
g M1.5
Distance from Earth
g 17.7 ly
Star Service No.
g NA
Age
g NA
Radius/Mass/Temp (xSol)
g 49.3%; 50.2%; NA
Brightness (xSol)
g 1.1%
Metallicity
g NA
Comparison to Sol
g See chart (similar to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g NA
Location in Earth sky
g NA
Other names
g GJ 526
g HD 119850
Sci-fi mentions
g NA
Thursday, August 23, 2007
GJ 445
Star type
g M3.5 V
Distance from Earth
g 17.54 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 24%; NA
Brightness (xSol)
g 0.0096%
Metallicity
g NA
Comparison to Sol
g See illustration
Picture of star
g See picture
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g NA
Location in Earth sky
g In constellation Camelopardalis
Other names
g HIP 57544
g LHS 2459
g AC+79 3888
Sci-fi mentions
g NA
g M3.5 V
Distance from Earth
g 17.54 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 24%; NA
Brightness (xSol)
g 0.0096%
Metallicity
g NA
Comparison to Sol
g See illustration
Picture of star
g See picture
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g NA
Location in Earth sky
g In constellation Camelopardalis
Other names
g HIP 57544
g LHS 2459
g AC+79 3888
Sci-fi mentions
g NA
Wednesday, August 22, 2007
G 099-049
Star type
g M3.5
Distance from Earth
g 17.05 ly
Star Service No.
g NA
Age
g NA
Radius/Mass/Temp (xSol)
g 27%; 20%; NA
Brightness (xSol)
g 0.3% (flare star)
Metallicity
g NA
Comparison to Sol
g See illustration (similar in size to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g Luyten’s Star: 7.7 ly
g Gliese 229: 7.9 ly
g 40 Eridani ABC: 8.1 ly
g Procyon AB: 8.8 ly
Map locating star system
g See stellar map (listed as “G99-49”)
Location in Earth sky
g In constellation Orion
Other names
g LTT 17897
g G99-49
Sci-fi mentions
g NA
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g M3.5
Distance from Earth
g 17.05 ly
Star Service No.
g NA
Age
g NA
Radius/Mass/Temp (xSol)
g 27%; 20%; NA
Brightness (xSol)
g 0.3% (flare star)
Metallicity
g NA
Comparison to Sol
g See illustration (similar in size to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g Luyten’s Star: 7.7 ly
g Gliese 229: 7.9 ly
g 40 Eridani ABC: 8.1 ly
g Procyon AB: 8.8 ly
Map locating star system
g See stellar map (listed as “G99-49”)
Location in Earth sky
g In constellation Orion
Other names
g LTT 17897
g G99-49
Sci-fi mentions
g NA
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Tuesday, August 21, 2007
EI Cancri AB
Star type
g A: M8 V
g B: M5.5 V
Distance from Earth
g 17.0498 ly
Star Service No.
g NA
Age
g A: NA
g B: NA
Diameter/Mass/Temp (xSol)
g A: NA; 6.2%; NA
g B: NA; 5%; NA
Brightness (xSol)
g A: 0.006%
g B: 0.003%
Metallicity
g NA
Comparison to Sol
g See illustration (similar in size to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g Stars separated by 23.5 AU
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g DX Cancri: 5.7 ly
g Groombridge 1618: 7.3 ly
g Procyon: 8 ly
g Luyten’s Star: 8 ly
Map locating star system
g See stellar map (listed as “G9-38”)
Location in Earth sky
g In constellation Cancer
Other names
g A: LHS 2076, NS 0858+1945 A, V* EI Cnc, GSC 01397-01138, USNO 314, G 9-38, RBS 730, Zkh 123, G 47-14, LSPM J0858+1945a, RX J0858.2+1946, [FS2003] 0490, G 41-11, LTT 12343 1RXS J085816.5+194648, [GKL99] 192, G 9-38A, 2MASS J08581519+1945470, StM 115 [GKL99] 193, GJ 1116 A, NLTT 20638, USNO-B1.0 1097-00167487, [RHG95] 1398
g B: LP 426-20, LHS 2077, LP 426-40, 8pc 191.20B, [RHG95] 1399, G 9-38B, LSPM J0858+1945b, USNO 315, GJ 1116 B, NLTT 20637, Zkh 124
Sci-fi mentions
g In "Star trek universe, based on "Star Trek Star Charts," can deduce it is in Federation space
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g A: M8 V
g B: M5.5 V
Distance from Earth
g 17.0498 ly
Star Service No.
g NA
Age
g A: NA
g B: NA
Diameter/Mass/Temp (xSol)
g A: NA; 6.2%; NA
g B: NA; 5%; NA
Brightness (xSol)
g A: 0.006%
g B: 0.003%
Metallicity
g NA
Comparison to Sol
g See illustration (similar in size to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g Stars separated by 23.5 AU
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g DX Cancri: 5.7 ly
g Groombridge 1618: 7.3 ly
g Procyon: 8 ly
g Luyten’s Star: 8 ly
Map locating star system
g See stellar map (listed as “G9-38”)
Location in Earth sky
g In constellation Cancer
Other names
g A: LHS 2076, NS 0858+1945 A, V* EI Cnc, GSC 01397-01138, USNO 314, G 9-38, RBS 730, Zkh 123, G 47-14, LSPM J0858+1945a, RX J0858.2+1946, [FS2003] 0490, G 41-11, LTT 12343 1RXS J085816.5+194648, [GKL99] 192, G 9-38A, 2MASS J08581519+1945470, StM 115 [GKL99] 193, GJ 1116 A, NLTT 20638, USNO-B1.0 1097-00167487, [RHG95] 1398
g B: LP 426-20, LHS 2077, LP 426-40, 8pc 191.20B, [RHG95] 1399, G 9-38B, LSPM J0858+1945b, USNO 315, GJ 1116 B, NLTT 20637, Zkh 124
Sci-fi mentions
g In "Star trek universe, based on "Star Trek Star Charts," can deduce it is in Federation space
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Monday, August 20, 2007
Altair
Star type
g A7
Distance from Earth
g 16.72 ly
Star Service No.
g NA
Age
g Few hundred million years old
Diameter/Mass/Temp (xSol)
g 170%; 180%; 8000 K
Brightness (xSol)
g 1070% (radiates higher than Sun in ultraviolet wavelengths)
Metallicity
g 200%
Comparison to Sol
g See illustration (Altair is slightly smaller than Sirius)
Picture of star
g See picture
Star system features
g Altair is 14 percent wider than it is tall (see video)
g Future: Will exhaust its core hydrogen around only a billion years and turn into a red giant or Cepheid variable before puffing away its outer layers to reveal a remnant core as a white dwarf
Known planets
g None, but dust has been detected around star; this dust disk may have developed after most of the surrounding nebulae of gas has been absorbed or expelled as a shell of gas from the developing star before it reached the main sequence
Habitable zone
g Distance where an Earth-type planet would be "comfortable" with liquid water is centered around 3.4 AUs, at the outer reaches of the Main Asteroid Belt's orbital distance in the Solar System. At that distance from the star, such a planet would have an orbital period of about 4.4 Earth years. If there is life on any Earth-type planet orbiting youthful Altair, it is likely to be primitive single-cell, anaerobic (non-oxygen producing) bacteria under constant bombardment by meteorites and comets as Earth was for the first billion years. Since there is unlikely to be free oxygen in the atmosphere of such a planet, it probably would not have an ozone layer (O3) although Altair puts out a lot more hard radiation (especially ultraviolet) than Sol.
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g Ross 652 A/Van Biesbroeck's: 3.7 ly
g 70 Ophiuchi AB: 7.8 ly
g Hip 103039: 9.1 ly
g 61 Cygni AB: 9.8 ly
g V1581 Cygni AB: 9.8 ly
g AC+17 534-105: 10 ly
Map locating star system
g See stellar map
Location in Earth sky
g In the north central part of Constellation Aquila, the Eagle. It is also the lower left member of the "Summer Triangle" of first magnitude stars viewed from the northern hemisphere, formed with Vega (Alpha Lyrae) at the lower right, and Deneb (Alpha Cygni) at upper right. Altair is readily visible to the naked eye.
Other names
g Alpha Aquilae
g GJ 768
g HD 165341
g HIP 97649
g LHS 3490
g NSV 24910
g Alp or Alf Aql
g 53 Aql
g HR 7557
g BD+08 4236
g SAO 125122
g FK5 745
g LTT 15795
g LFT 1499
g ADS 13009 A
Sci-fi mentions
g In “The Hitchhikers Guide to the Galaxy,” the common currency is the Altairian Dollar.
g In the novel Sunstorm, a gas giant fifteen times the mass of Jupiter was launched by the Firstborn alien race from the Altair star system on a collision course with Earth's Sun in order to trigger a devastating solar flare that would completely sterilize the Earth.
g Altair is the home of Ahrian in Leigh Brackett's "The Woman from Altair".
g Altair VI is a planet in "The Winds of Altair" by Ben Bova, a novel about the colonization and terraforming of this planet, which is home to a race as intelligent as man.
g Angharad Gwyn is born and rescued from the planet Altair in "The Rowan" by Anne McCaffrey.
g In Stephen King's novel "The Tommyknockers", Altair IV is a desolate, nearly airless world where objects from all over the galaxy are stored. The name is most likely a reference to "Forbidden Planet" below.
g Edmund Cooper's "A Far Sunset" (Ace Books, 1967) has the starship Gloria Mundi meeting the Bayani race on Altair V in 2028
g Altair is the homeworld of Harlan, an artificial lifeform in "Stargate SG-1".
g The planet Altair IV is the main setting of the film "Forbidden Planet".
g Altair IV is the location of a prestigious hospital in the "Star Trek: Deep Space 9" episode "Prophet Motive", and a planet recovering from war with neighboring Altair VI in the "Star Trek: The Original Series" episode "Amok Time". Altair water is a commercially available beverage from the Altair system; in the movie "Star Trek III: The Search for Spock", McCoy drinks Altair water. The Altair sandwich is named after the star (DS9: "You Are Cordially Invited"), and "Setar of Altair" apparently is an important, well-known person (TOS: The Ultimate Computer").
g Altair V is the planet of origin for Rafael Argus in the '70s Buck Rogers episode "Plot to Kill A City"
g Altair III is mentioned in the play "Doctor Who - The Ultimate Adventure".
g In the Futurama episode "The Cyber House Rules", Adlai and Leela walk past an Altairean Bouquet Tree. Altair may simply be the name of the planetary system, and not the planet.
g In the game "Galactic Civilizations", there is a race known as the Altarians.
g Altair is the homeworld of the Ancients, an extinct civilization annihilated by the Shivans 8,000 years ago, in the space-combat simulation game, "FreeSpace 2".
g Altair is the homeworld of the Alkari, one of the alien races in the "Master of Orion" computer game series.
g The "Third Planet from Altair" (Choose Your Own Adventure #7, by Edward Packard, author, and Paul Granger, illustrator) describes in multiple scenarios an expedition to the planet of the namesake to investigate the source of transmitted signals received by Earth.
g In the "Frontier: Elite II" and "Frontier: First Encounters" games, Altair has a habitable world and a profitable tourism industry. It is also a Federation member.
g Altair Nine is an earth colony in Frederik Pohl's short story "The Day the Icicle Works Closed"
g A7
Distance from Earth
g 16.72 ly
Star Service No.
g NA
Age
g Few hundred million years old
Diameter/Mass/Temp (xSol)
g 170%; 180%; 8000 K
Brightness (xSol)
g 1070% (radiates higher than Sun in ultraviolet wavelengths)
Metallicity
g 200%
Comparison to Sol
g See illustration (Altair is slightly smaller than Sirius)
Picture of star
g See picture
Star system features
g Altair is 14 percent wider than it is tall (see video)
g Future: Will exhaust its core hydrogen around only a billion years and turn into a red giant or Cepheid variable before puffing away its outer layers to reveal a remnant core as a white dwarf
Known planets
g None, but dust has been detected around star; this dust disk may have developed after most of the surrounding nebulae of gas has been absorbed or expelled as a shell of gas from the developing star before it reached the main sequence
Habitable zone
g Distance where an Earth-type planet would be "comfortable" with liquid water is centered around 3.4 AUs, at the outer reaches of the Main Asteroid Belt's orbital distance in the Solar System. At that distance from the star, such a planet would have an orbital period of about 4.4 Earth years. If there is life on any Earth-type planet orbiting youthful Altair, it is likely to be primitive single-cell, anaerobic (non-oxygen producing) bacteria under constant bombardment by meteorites and comets as Earth was for the first billion years. Since there is unlikely to be free oxygen in the atmosphere of such a planet, it probably would not have an ozone layer (O3) although Altair puts out a lot more hard radiation (especially ultraviolet) than Sol.
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g Ross 652 A/Van Biesbroeck's: 3.7 ly
g 70 Ophiuchi AB: 7.8 ly
g Hip 103039: 9.1 ly
g 61 Cygni AB: 9.8 ly
g V1581 Cygni AB: 9.8 ly
g AC+17 534-105: 10 ly
Map locating star system
g See stellar map
Location in Earth sky
g In the north central part of Constellation Aquila, the Eagle. It is also the lower left member of the "Summer Triangle" of first magnitude stars viewed from the northern hemisphere, formed with Vega (Alpha Lyrae) at the lower right, and Deneb (Alpha Cygni) at upper right. Altair is readily visible to the naked eye.
Other names
g Alpha Aquilae
g GJ 768
g HD 165341
g HIP 97649
g LHS 3490
g NSV 24910
g Alp or Alf Aql
g 53 Aql
g HR 7557
g BD+08 4236
g SAO 125122
g FK5 745
g LTT 15795
g LFT 1499
g ADS 13009 A
Sci-fi mentions
g In “The Hitchhikers Guide to the Galaxy,” the common currency is the Altairian Dollar.
g In the novel Sunstorm, a gas giant fifteen times the mass of Jupiter was launched by the Firstborn alien race from the Altair star system on a collision course with Earth's Sun in order to trigger a devastating solar flare that would completely sterilize the Earth.
g Altair is the home of Ahrian in Leigh Brackett's "The Woman from Altair".
g Altair VI is a planet in "The Winds of Altair" by Ben Bova, a novel about the colonization and terraforming of this planet, which is home to a race as intelligent as man.
g Angharad Gwyn is born and rescued from the planet Altair in "The Rowan" by Anne McCaffrey.
g In Stephen King's novel "The Tommyknockers", Altair IV is a desolate, nearly airless world where objects from all over the galaxy are stored. The name is most likely a reference to "Forbidden Planet" below.
g Edmund Cooper's "A Far Sunset" (Ace Books, 1967) has the starship Gloria Mundi meeting the Bayani race on Altair V in 2028
g Altair is the homeworld of Harlan, an artificial lifeform in "Stargate SG-1".
g The planet Altair IV is the main setting of the film "Forbidden Planet".
g Altair IV is the location of a prestigious hospital in the "Star Trek: Deep Space 9" episode "Prophet Motive", and a planet recovering from war with neighboring Altair VI in the "Star Trek: The Original Series" episode "Amok Time". Altair water is a commercially available beverage from the Altair system; in the movie "Star Trek III: The Search for Spock", McCoy drinks Altair water. The Altair sandwich is named after the star (DS9: "You Are Cordially Invited"), and "Setar of Altair" apparently is an important, well-known person (TOS: The Ultimate Computer").
g Altair V is the planet of origin for Rafael Argus in the '70s Buck Rogers episode "Plot to Kill A City"
g Altair III is mentioned in the play "Doctor Who - The Ultimate Adventure".
g In the Futurama episode "The Cyber House Rules", Adlai and Leela walk past an Altairean Bouquet Tree. Altair may simply be the name of the planetary system, and not the planet.
g In the game "Galactic Civilizations", there is a race known as the Altarians.
g Altair is the homeworld of the Ancients, an extinct civilization annihilated by the Shivans 8,000 years ago, in the space-combat simulation game, "FreeSpace 2".
g Altair is the homeworld of the Alkari, one of the alien races in the "Master of Orion" computer game series.
g The "Third Planet from Altair" (Choose Your Own Adventure #7, by Edward Packard, author, and Paul Granger, illustrator) describes in multiple scenarios an expedition to the planet of the namesake to investigate the source of transmitted signals received by Earth.
g In the "Frontier: Elite II" and "Frontier: First Encounters" games, Altair has a habitable world and a profitable tourism industry. It is also a Federation member.
g Altair Nine is an earth colony in Frederik Pohl's short story "The Day the Icicle Works Closed"
Sunday, August 19, 2007
70 Ophiuchi AB
Star type
g A: K0-1 Ve
g B: K5-6 Ve
Distance from Earth
g 16.6 ly
Star Service No.
g NA
Age
g A: 3.998 billion years
g B: 5.441 billion years
Diameter/Mass/Temp (xSol)
g A: 89%; 92%; 5290 K
g B: 73%; 70%; 4250 K
Brightness (xSol)
g A: 49%
g B: 8.4% to 9%
Metallicity
g A: 30% to 100% (probably about 73%)
g B: 73%
Comparison to Sol
g See illustration (stars are similar to Alpha Centauri B and GJ205)
Picture of star
g A and B: See picture
g A: See picture
Star system features
g Stars A and B have a relatively wide separation, on average by a semi-major axis of 23.2 AUs (4.554") in a highly elliptical orbit (e= 0.499) that takes 83.38 years to complete. The distance separating the two stars varies from 11.4 and 34.8 AUs; they are always separated from each other by roughly the orbital distance of Saturn in the Solar System. Lastly, the inclination of the orbit is 121.2° from the perspective of an observer on Earth. The last close approach was in 1984, the next greatest separation will be in 2028.
g Future: System is near its closest approach to the Sun, the distance shortening to 15 light years 75,000 years from now
Known planets
g A: None
g B: None
Habitable zone
g A: The orbital distance where an Earth-type planet would have liquid water is centered around 0.68 AU, near the Venus-Sun distance in the Solar System, where a planet's period would be about 228 days or almost two thirds of an Earth year; probability of a habitable planet is 5.7%
g B: Orbital distance where an Earth-type planet would have liquid water is centered around 0.30 AU, or three fourths of Mercury's orbital distance in the Solar System, where the orbital period would be over 77 days; probability of a habitable planet is less than 0.1%
Orbital map
g See map
View from star
g A: See sky map
g A: Artist’s interpretation of the 70 Ophiuchi system seen from a hypothetical moon-like world orbiting about the primary sun. The secondary, orange colored sun (70 Ophiuchi B) is seen in the distance to the upper right.
g B: NA (but virtually identical to Star A)
Nearby stars
(Star systems with 10 light years)
g Ross 652 A/Van Biesbroeck's: 6.1 ly
g Hip 85605: 6.7 ly
g Wolf 630 A-C: 6.7 ly
g Altair: 7.8 ly
g BD-12 4523 AB: 7.9 ly
g Wolf 629 AB: 8.2 ly
g BD-03 4233: 9.1 ly
g BD+02 3312: 9.3 ly
g Ross 154: 9.3 ly
g G 154-44: 9.9 ly
Map locating star system
g See stellar map
Location in Earth sky
g In the northeastern part of Constellation Ophiuchus, the Serpent Holder, east of Gamma Ophiuchi
Other names
g Gliese 702 AB
g A: HD 165341
g A: HIP 88601
g A: LHS 458
g A-B: 70 Oph AB
g A: HR 6752
g A-B: Gl 702 AB
g A: SAO 123107
g A: ADS 11046 A
g A: Struve 2272 A
g B: LHS 459
g B: Gl 702 B
g B: ADS 11046 B
g B: Struve 2272 B
Sci-fi mentions
g Dune and other novels in the Dune universe by Frank Herbert. Sikun is the third planet from 70 Ophiuchi.
g The Ophiuchi Hotline, novel by John Varley. Humanity survives with the aid of a technology derived from information in the Ophiuchi Hotline, a radio signal apparently beamed from the star 70 Ophiuchi.
g Frontier: Elite II and Frontier: First Encounters, computer games. This system has a mining and heavy industry based economy. For a mining system, its population of hundreds of thousands of people is impressive
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g A: K0-1 Ve
g B: K5-6 Ve
Distance from Earth
g 16.6 ly
Star Service No.
g NA
Age
g A: 3.998 billion years
g B: 5.441 billion years
Diameter/Mass/Temp (xSol)
g A: 89%; 92%; 5290 K
g B: 73%; 70%; 4250 K
Brightness (xSol)
g A: 49%
g B: 8.4% to 9%
Metallicity
g A: 30% to 100% (probably about 73%)
g B: 73%
Comparison to Sol
g See illustration (stars are similar to Alpha Centauri B and GJ205)
Picture of star
g A and B: See picture
g A: See picture
Star system features
g Stars A and B have a relatively wide separation, on average by a semi-major axis of 23.2 AUs (4.554") in a highly elliptical orbit (e= 0.499) that takes 83.38 years to complete. The distance separating the two stars varies from 11.4 and 34.8 AUs; they are always separated from each other by roughly the orbital distance of Saturn in the Solar System. Lastly, the inclination of the orbit is 121.2° from the perspective of an observer on Earth. The last close approach was in 1984, the next greatest separation will be in 2028.
g Future: System is near its closest approach to the Sun, the distance shortening to 15 light years 75,000 years from now
Known planets
g A: None
g B: None
Habitable zone
g A: The orbital distance where an Earth-type planet would have liquid water is centered around 0.68 AU, near the Venus-Sun distance in the Solar System, where a planet's period would be about 228 days or almost two thirds of an Earth year; probability of a habitable planet is 5.7%
g B: Orbital distance where an Earth-type planet would have liquid water is centered around 0.30 AU, or three fourths of Mercury's orbital distance in the Solar System, where the orbital period would be over 77 days; probability of a habitable planet is less than 0.1%
Orbital map
g See map
View from star
g A: See sky map
g A: Artist’s interpretation of the 70 Ophiuchi system seen from a hypothetical moon-like world orbiting about the primary sun. The secondary, orange colored sun (70 Ophiuchi B) is seen in the distance to the upper right.
g B: NA (but virtually identical to Star A)
Nearby stars
(Star systems with 10 light years)
g Ross 652 A/Van Biesbroeck's: 6.1 ly
g Hip 85605: 6.7 ly
g Wolf 630 A-C: 6.7 ly
g Altair: 7.8 ly
g BD-12 4523 AB: 7.9 ly
g Wolf 629 AB: 8.2 ly
g BD-03 4233: 9.1 ly
g BD+02 3312: 9.3 ly
g Ross 154: 9.3 ly
g G 154-44: 9.9 ly
Map locating star system
g See stellar map
Location in Earth sky
g In the northeastern part of Constellation Ophiuchus, the Serpent Holder, east of Gamma Ophiuchi
Other names
g Gliese 702 AB
g A: HD 165341
g A: HIP 88601
g A: LHS 458
g A-B: 70 Oph AB
g A: HR 6752
g A-B: Gl 702 AB
g A: SAO 123107
g A: ADS 11046 A
g A: Struve 2272 A
g B: LHS 459
g B: Gl 702 B
g B: ADS 11046 B
g B: Struve 2272 B
Sci-fi mentions
g Dune and other novels in the Dune universe by Frank Herbert. Sikun is the third planet from 70 Ophiuchi.
g The Ophiuchi Hotline, novel by John Varley. Humanity survives with the aid of a technology derived from information in the Ophiuchi Hotline, a radio signal apparently beamed from the star 70 Ophiuchi.
g Frontier: Elite II and Frontier: First Encounters, computer games. This system has a mining and heavy industry based economy. For a mining system, its population of hundreds of thousands of people is impressive
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Saturday, August 18, 2007
EV Lacertae ABC
Star type
g A: M3.5 Ve
g B: dM4.5e
g C: NA
Distance from Earth
g 16.47 ly
Star Service No.
g NA
Age
g A: NA
g B: NA
g C: NA
Diameter/Mass/Temp (xSol)
g A: 38%; 16%; NA
g B: NA: 16.5%(?); NA
g C: NA; NA; Na
Brightness (xSol)
g A: 0.17% (flare star)
g B: 0.1892%(?)
g C: NA
Metallicity
g A: NA
g B: NA
g C: NA
Comparison to Sol
g See illustration (Stars A and B similar to Proxima)
Picture of star
g See picture
Star system features
g Research paper “Is the Flare Star Ev-Lacertae an Eclipsing Binary?”
g Research paper “The Quiescent Atmosphere of the dMe Flare Star EV Lacertae”
Known planets
g A: NA
g B: NA
g C: NA
Habitable zone
g A: About 0.012 to 0.02 AU when it is quiet; about 0.028 to 0.047 AU during a moderate flare
g B: NA
g C: NA
Orbital map
g NA
View from star
g A: See sky map
Nearby stars
(Star systems with 10 light years)
g BD+56 2966: 6.3 ly
Map locating star system
g NA
Location in Earth sky
g In constellation Lacerta
Other names
g GJ 873 ABC
g A: LHS 3855
g A: HIP 112460
g B: HIP 112465
Sci-fi mentions
g NA
g A: M3.5 Ve
g B: dM4.5e
g C: NA
Distance from Earth
g 16.47 ly
Star Service No.
g NA
Age
g A: NA
g B: NA
g C: NA
Diameter/Mass/Temp (xSol)
g A: 38%; 16%; NA
g B: NA: 16.5%(?); NA
g C: NA; NA; Na
Brightness (xSol)
g A: 0.17% (flare star)
g B: 0.1892%(?)
g C: NA
Metallicity
g A: NA
g B: NA
g C: NA
Comparison to Sol
g See illustration (Stars A and B similar to Proxima)
Picture of star
g See picture
Star system features
g Research paper “Is the Flare Star Ev-Lacertae an Eclipsing Binary?”
g Research paper “The Quiescent Atmosphere of the dMe Flare Star EV Lacertae”
Known planets
g A: NA
g B: NA
g C: NA
Habitable zone
g A: About 0.012 to 0.02 AU when it is quiet; about 0.028 to 0.047 AU during a moderate flare
g B: NA
g C: NA
Orbital map
g NA
View from star
g A: See sky map
Nearby stars
(Star systems with 10 light years)
g BD+56 2966: 6.3 ly
Map locating star system
g NA
Location in Earth sky
g In constellation Lacerta
Other names
g GJ 873 ABC
g A: LHS 3855
g A: HIP 112460
g B: HIP 112465
Sci-fi mentions
g NA
Friday, August 17, 2007
40 Eridani ABC
Star type
g A: K1
g B: DA4
g C: M4.5 Ve
Distance from Earth
g 16.38 ly
Star Service No.
g NA
Age
g A: 4.109 Gy to 12.109 Gy
g B: 4.109 Gy to 12.109 Gy
g C: 4.109 Gy to 12.109 Gy
Diameter/Mass/Temp (xSol)
g A: 85%; 89%; 5,200 K
g B: 2%; 50%; 16,500 K
g C: 28%; 19.5%; 3,100 K
Brightness (xSol)
g A: 36%
g B: 33/10,000th
g C: 7/10,000th
Metallicity
g A: 46 percent to 102 percent as enriched as Sol with elements heavier than hydrogen
g B: NA
g C: NA
Comparison to Sol
g See illustration
Picture of star
g A: See picture
g A-B-C: See picture
Star system features
g B: First white dwarf discovered
g C: Strong X-ray emission
Known planets
g A: No brown dwarf or large Jupiter or Saturn class planet in the triple star system thus far
g B: None
g C: None
Habitable zone
g A: The habitable zone of 40 Eri A, where a planet could exist with liquid water, is near 0.61 AU from A. At this distance a planet would complete a revolution in 203 earth days, and A would appear about 30% wider than Sol does on Earth. An observer on a planet in the 40 Eri A system would see the B/C pair as unusually bright (magnitudes -8 and -6) white and red stars in the night sky. This is not bright enough to diminish the darkness at night, though they would be visible during daytime. (By comparison, Earth's full moon is magnitude -12.6, and Venus at its brightest is -4.). An expedition to a terrestrial planet around this star might conduct studies to determine of there is a geological record of the red giant winds from 40 Eridani C before it became a white dwarf; ice ages due to the dusty space caused by Star C's red giant phase is one possibility.
g B: The current water zone is centered around 0.06 AU which would require an orbital period of about 7.8 days. It is extremely unlikely that habitable planets exist around the B star as planets circling 40 Eri B would likely have been destroyed or sterilized by its evolution into a white dwarf.
g C: Its water zone is 0.03 AU (which has an orbital period of only about 4.3 days. The star is prone to flares, however, which cause large momentary increases in the emission of X-rays as well as visible light.This would be lethal to a planet in the habitable zone.
Orbital map
g See map
g Star A and the binary pair BC have a wide separation of about 418 AUs and an orbital period of some 8,000 years
g B and C orbit each other approximately 400 astronomical units from the primary star, A. Their orbit has a semimajor axis of 35 AU (which is also the approximate average distance between B and C) and is rather elliptical (eccentricity 0.410).
View from star
g A: See sky map
g B: NA but nearly identical to Star A (except for lack of Star A and Star C in sky)
g C: NA but nearly identical to Star A (except for lack of Star A and Star B in sky)
Nearby stars
(Star systems with 10 light years)
g LHS 1723: 3.8 ly
g Hip 15689: 4.4 ly
g BD-03 1123: 6.2 ly
g Epsilon Eridani: 6.4 ly
g LTT 17897: 8.1 ly
g LP 944-20: 8.2 ly (brown dwarf)
g Teegarden's Star: ~8.7 ly
g L 730-18 ABC; 8.9 ly
g G 99-44: 9.1 ly
g Ross 614 AB: 9.1 ly
g Ross 47: 9.3 ly
g Gliese 229; 9.8 ly
Map locating star system
g See stellar map (listed as ο2 Eri)
Location in Earth sky
g In the northernmost part of Constellation Eridanus, the River, northeast of Zaurak, Gamma Eridani. Star A is visible in the night sky.
Other names
g Keid
g A: HD 26965
g A: ο2 Eri A
g A: o2 Eridani A
g A: 40 Eri A
g ADS 3093A
g BD -07°780
g CCDM J04153-0739A
g GCTP 945
g GJ 166 A
g A: HIP 19849
g A: HR 1325
g LHS 23
g A: LTT 1907
g SAO 131063
g STF 518A
g A-B: 40 Omicron 2
g A-B-C: HIP 19849
g B: ο2 Eri B
g B: o2 Eridani B
g B: 40 Eri B
g B: ADS 3093B
g B: BD -07°781A
g B: CCDM J04153-0739B
g B: G 160-060
g B: GCTP 945
g B: GJ 166 B
g B: HD 26976
g B: LHS 24
g B: LTT 1908
g B: SAO 131065
g B: WD 0413-077
g B: STF 518B
g C: DY Eri
g C: DY Eridani
g C: ο2 Eri C
g C: o2 Eridani C
g C: 40 Eri C
g C: ADS 3093C
g C: BD -07°781B
g C: BD -07°781C
g C: CCDM J04153-0739C
g C: GCTP 945
g C: GJ 166 C
g C: LHS 25
g C: LTT 1909
g C: STF 518C
Sci-fi mentions
g 40 Eridani A is the location of the planet Vulcan, home of the Vulcan species. Although this was never stated on any TV show or film, both the authorized Star Trek book "Star Trek: Star Charts" and Gene Roddenberry gave this location. In addition, Commander Tucker's statement in Star Trek: Enterprise that Vulcan is 16 light years from Earth confirms this.
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g A: K1
g B: DA4
g C: M4.5 Ve
Distance from Earth
g 16.38 ly
Star Service No.
g NA
Age
g A: 4.109 Gy to 12.109 Gy
g B: 4.109 Gy to 12.109 Gy
g C: 4.109 Gy to 12.109 Gy
Diameter/Mass/Temp (xSol)
g A: 85%; 89%; 5,200 K
g B: 2%; 50%; 16,500 K
g C: 28%; 19.5%; 3,100 K
Brightness (xSol)
g A: 36%
g B: 33/10,000th
g C: 7/10,000th
Metallicity
g A: 46 percent to 102 percent as enriched as Sol with elements heavier than hydrogen
g B: NA
g C: NA
Comparison to Sol
g See illustration
Picture of star
g A: See picture
g A-B-C: See picture
Star system features
g B: First white dwarf discovered
g C: Strong X-ray emission
Known planets
g A: No brown dwarf or large Jupiter or Saturn class planet in the triple star system thus far
g B: None
g C: None
Habitable zone
g A: The habitable zone of 40 Eri A, where a planet could exist with liquid water, is near 0.61 AU from A. At this distance a planet would complete a revolution in 203 earth days, and A would appear about 30% wider than Sol does on Earth. An observer on a planet in the 40 Eri A system would see the B/C pair as unusually bright (magnitudes -8 and -6) white and red stars in the night sky. This is not bright enough to diminish the darkness at night, though they would be visible during daytime. (By comparison, Earth's full moon is magnitude -12.6, and Venus at its brightest is -4.). An expedition to a terrestrial planet around this star might conduct studies to determine of there is a geological record of the red giant winds from 40 Eridani C before it became a white dwarf; ice ages due to the dusty space caused by Star C's red giant phase is one possibility.
g B: The current water zone is centered around 0.06 AU which would require an orbital period of about 7.8 days. It is extremely unlikely that habitable planets exist around the B star as planets circling 40 Eri B would likely have been destroyed or sterilized by its evolution into a white dwarf.
g C: Its water zone is 0.03 AU (which has an orbital period of only about 4.3 days. The star is prone to flares, however, which cause large momentary increases in the emission of X-rays as well as visible light.This would be lethal to a planet in the habitable zone.
Orbital map
g See map
g Star A and the binary pair BC have a wide separation of about 418 AUs and an orbital period of some 8,000 years
g B and C orbit each other approximately 400 astronomical units from the primary star, A. Their orbit has a semimajor axis of 35 AU (which is also the approximate average distance between B and C) and is rather elliptical (eccentricity 0.410).
View from star
g A: See sky map
g B: NA but nearly identical to Star A (except for lack of Star A and Star C in sky)
g C: NA but nearly identical to Star A (except for lack of Star A and Star B in sky)
Nearby stars
(Star systems with 10 light years)
g LHS 1723: 3.8 ly
g Hip 15689: 4.4 ly
g BD-03 1123: 6.2 ly
g Epsilon Eridani: 6.4 ly
g LTT 17897: 8.1 ly
g LP 944-20: 8.2 ly (brown dwarf)
g Teegarden's Star: ~8.7 ly
g L 730-18 ABC; 8.9 ly
g G 99-44: 9.1 ly
g Ross 614 AB: 9.1 ly
g Ross 47: 9.3 ly
g Gliese 229; 9.8 ly
Map locating star system
g See stellar map (listed as ο2 Eri)
Location in Earth sky
g In the northernmost part of Constellation Eridanus, the River, northeast of Zaurak, Gamma Eridani. Star A is visible in the night sky.
Other names
g Keid
g A: HD 26965
g A: ο2 Eri A
g A: o2 Eridani A
g A: 40 Eri A
g ADS 3093A
g BD -07°780
g CCDM J04153-0739A
g GCTP 945
g GJ 166 A
g A: HIP 19849
g A: HR 1325
g LHS 23
g A: LTT 1907
g SAO 131063
g STF 518A
g A-B: 40 Omicron 2
g A-B-C: HIP 19849
g B: ο2 Eri B
g B: o2 Eridani B
g B: 40 Eri B
g B: ADS 3093B
g B: BD -07°781A
g B: CCDM J04153-0739B
g B: G 160-060
g B: GCTP 945
g B: GJ 166 B
g B: HD 26976
g B: LHS 24
g B: LTT 1908
g B: SAO 131065
g B: WD 0413-077
g B: STF 518B
g C: DY Eri
g C: DY Eridani
g C: ο2 Eri C
g C: o2 Eridani C
g C: 40 Eri C
g C: ADS 3093C
g C: BD -07°781B
g C: BD -07°781C
g C: CCDM J04153-0739C
g C: GCTP 945
g C: GJ 166 C
g C: LHS 25
g C: LTT 1909
g C: STF 518C
Sci-fi mentions
g 40 Eridani A is the location of the planet Vulcan, home of the Vulcan species. Although this was never stated on any TV show or film, both the authorized Star Trek book "Star Trek: Star Charts" and Gene Roddenberry gave this location. In addition, Commander Tucker's statement in Star Trek: Enterprise that Vulcan is 16 light years from Earth confirms this.
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Thursday, August 16, 2007
GJ 682
Star type
g M3.5-4.5 V-VI
Distance from Earth
g 16.33 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 21%; NA
Brightness (xSol)
g 0.66%
Metallicity
g NA
Comparison to Sol
g See illustration (similar in size to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g GJ 667 ABC: 8 ly
Map locating star system
g See stellar map (listed as “CD–44° 11909”)
Location in Earth sky
g In the constellation Ara
g See sky map
Other names
g HIP 86214
g LHS 451
g CD–44° 11909
Sci-fi mentions
g NA
g M3.5-4.5 V-VI
Distance from Earth
g 16.33 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 21%; NA
Brightness (xSol)
g 0.66%
Metallicity
g NA
Comparison to Sol
g See illustration (similar in size to Proxima)
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g GJ 667 ABC: 8 ly
Map locating star system
g See stellar map (listed as “CD–44° 11909”)
Location in Earth sky
g In the constellation Ara
g See sky map
Other names
g HIP 86214
g LHS 451
g CD–44° 11909
Sci-fi mentions
g NA
Wednesday, August 15, 2007
Den 0255-4700
Star type
g L7.5V (not truly a star)
Distance from Earth
g 16.197 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 7%; 2,600 F
Brightness (xSol)
g Nearly 100 million times fainter (as of Aug. 2006, the faintest object outside our solar system for which its intrinsic visual brightness has been measured)
Metallicity
g Exotic elements such as potassium, rubidium, and cesium in its outer atmosphere, mixed with superheated water
Comparison to Sol
g See illustration
Picture of star
g See illustration
Star system features
g Closest L dwarf to Earth
g Star boasts a brown dwarf companion, SCR 1845-6357
Known planets
g NA
Habitable zone
g Unlikely though moons around a gas giant orbiting dwarf might support life
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See stellar map
Location in Earth sky
g In Constellation Eridanus
Other names
g NA
Sci-fi mentions
g NA
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g L7.5V (not truly a star)
Distance from Earth
g 16.197 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 7%; 2,600 F
Brightness (xSol)
g Nearly 100 million times fainter (as of Aug. 2006, the faintest object outside our solar system for which its intrinsic visual brightness has been measured)
Metallicity
g Exotic elements such as potassium, rubidium, and cesium in its outer atmosphere, mixed with superheated water
Comparison to Sol
g See illustration
Picture of star
g See illustration
Star system features
g Closest L dwarf to Earth
g Star boasts a brown dwarf companion, SCR 1845-6357
Known planets
g NA
Habitable zone
g Unlikely though moons around a gas giant orbiting dwarf might support life
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See stellar map
Location in Earth sky
g In Constellation Eridanus
Other names
g NA
Sci-fi mentions
g NA
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Tuesday, August 14, 2007
LP 944-020
Star type
g Brown dwarf
Distance from Earth
g 16.19 ly
Star Service No.
g NA
Age
g About 475 to 650 million years old but may be around 320 million years old if it is a member of the Castor moving group
Diamater/Mass/Temp (xSol)
g 10%; 64xJupiter; about 900 K
Brightness (xSol)
g 14.5/100,000th
Metallicity
g NA
Comparison to Sol
g See illustration
Picture of star
g See picture
Star system features
g Appears to be a member of the Castor moving group
g Changes in the surface chemistry of the brown dwarf suggested that it had weather patterns with winds, clouds and storms, similar to those found on a gas giant planet like Jupiter
g Can release X-ray flares; once thought to be a red dwarf but recently reclassified
Known planets
g None
Habitable zone
g Unlikely to support life except on moons of orbiting gas giants (of which none have been found)
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g 82 Eridani AB: 4.4 ly
g LHS 1565 / GJ 1061: 4.9 ly
g Kapteyn's Star: 6.1 ly
g Hip 15689: 6.3 ly
g 40 Eridani 3: 8.2 ly
g Epsilon Eridani: 8.3 ly
g Tau Ceti: 8.9 ly
g YZ Ceti: 10 ly
Map locating star system
g See stellar map
Location in Earth sky
g In eastern part of Constellation Fornax, the Furnace, in the southern hemisphere - southeast of Alpha Fornacis and northeast of Acamar (Theta1 Eridani)
Other names
g BRI 0337-3535
g 2MASS J03393521-3525440
g 2MASSW J0339352-352544
g APMPM J0340-3526
g BRI 0337-3535
g BRI B0337-3535
g LEHPM 3451
g N3 9
g NS 0339-3525
Sci-fi mentions
g “Jacob’s Ladder”, flash fiction story by Daivos
g Brown dwarf
Distance from Earth
g 16.19 ly
Star Service No.
g NA
Age
g About 475 to 650 million years old but may be around 320 million years old if it is a member of the Castor moving group
Diamater/Mass/Temp (xSol)
g 10%; 64xJupiter; about 900 K
Brightness (xSol)
g 14.5/100,000th
Metallicity
g NA
Comparison to Sol
g See illustration
Picture of star
g See picture
Star system features
g Appears to be a member of the Castor moving group
g Changes in the surface chemistry of the brown dwarf suggested that it had weather patterns with winds, clouds and storms, similar to those found on a gas giant planet like Jupiter
g Can release X-ray flares; once thought to be a red dwarf but recently reclassified
Known planets
g None
Habitable zone
g Unlikely to support life except on moons of orbiting gas giants (of which none have been found)
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g 82 Eridani AB: 4.4 ly
g LHS 1565 / GJ 1061: 4.9 ly
g Kapteyn's Star: 6.1 ly
g Hip 15689: 6.3 ly
g 40 Eridani 3: 8.2 ly
g Epsilon Eridani: 8.3 ly
g Tau Ceti: 8.9 ly
g YZ Ceti: 10 ly
Map locating star system
g See stellar map
Location in Earth sky
g In eastern part of Constellation Fornax, the Furnace, in the southern hemisphere - southeast of Alpha Fornacis and northeast of Acamar (Theta1 Eridani)
Other names
g BRI 0337-3535
g 2MASS J03393521-3525440
g 2MASSW J0339352-352544
g APMPM J0340-3526
g BRI 0337-3535
g BRI B0337-3535
g LEHPM 3451
g N3 9
g NS 0339-3525
Sci-fi mentions
g “Jacob’s Ladder”, flash fiction story by Daivos
Monday, August 13, 2007
GJ 832
Star type
g M1.5V-M3
Distance from Earth
g 16.08 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 50%; NA
Brightness (xSol)
g 32%
Metallicity
g NA
Comparison to Sol
g See illustration
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g Epsilon Indi: 4.8 ly
g GJ 783 A: 7.1 ly
Map locating star system
g NA
Location in Earth sky
g In constellation Indus
Other names
g CD-49 13515
g HD 204961
g HIP 106440
g LHS 3685
g L 354-89
g Sm 83
Sci-fi mentions
g NA
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g M1.5V-M3
Distance from Earth
g 16.08 ly
Star Service No.
g NA
Age
g NA
Diameter/Mass/Temp (xSol)
g NA; 50%; NA
Brightness (xSol)
g 32%
Metallicity
g NA
Comparison to Sol
g See illustration
Picture of star
g NA
Star system features
g NA
Known planets
g NA
Habitable zone
g NA
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g Epsilon Indi: 4.8 ly
g GJ 783 A: 7.1 ly
Map locating star system
g NA
Location in Earth sky
g In constellation Indus
Other names
g CD-49 13515
g HD 204961
g HIP 106440
g LHS 3685
g L 354-89
g Sm 83
Sci-fi mentions
g NA
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Sunday, August 12, 2007
GJ 388
Star type
g dM4.5Ve
Distance from Earth
g 15.93 ly
Star Service No.
g NA
Age
g 100 million years
RadiusMass/Temp (xSol)
g 54%; 28%; NA
Brightness (xSol)
g 0.38% (flare star)
Metallicity
g 1%
Comparison to Sol
g See illustration
Picture of star
g NA
Star system features
g Has an unseen companion of P ~ 27 yr.; is expected to have a very low mass and probably is a brown dwarf
g See paper "X-ray spectroscopy of the active dM stars: AD Leo and EV Lac"
g See paper “PHOENIX model chromospheres of mid- to late-type M dwarfs"
Known planets
g NA
Habitable zone
g Zone is 0.023 to 0.033 AUs when quiet but 0.123 to 0.187 AU during a strong flare. Star likely is too young to support any life, however.
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See stellar map (listed as “BD+20 2465”)
Location in Earth sky
g In the constellation Leo
Other names
g AD Leo AD Leonis, 40 Leo, LHS 5167, CNS3 1616, BD+20 2465, G 054-023, SAO 81292, LTT 12761, ADS 7724 C, Vys 574, Yale 2420, Cinc 20C574, GCRV 6499, EUVE J1019+19.8, RE J101935+195212, EXO 1016.8+2007
Sci-fi mentions
g NA
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g dM4.5Ve
Distance from Earth
g 15.93 ly
Star Service No.
g NA
Age
g 100 million years
RadiusMass/Temp (xSol)
g 54%; 28%; NA
Brightness (xSol)
g 0.38% (flare star)
Metallicity
g 1%
Comparison to Sol
g See illustration
Picture of star
g NA
Star system features
g Has an unseen companion of P ~ 27 yr.; is expected to have a very low mass and probably is a brown dwarf
g See paper "X-ray spectroscopy of the active dM stars: AD Leo and EV Lac"
g See paper “PHOENIX model chromospheres of mid- to late-type M dwarfs"
Known planets
g NA
Habitable zone
g Zone is 0.023 to 0.033 AUs when quiet but 0.123 to 0.187 AU during a strong flare. Star likely is too young to support any life, however.
Orbital map
g NA
View from star
g NA
Nearby stars
(Star systems with 10 light years)
g NA
Map locating star system
g See stellar map (listed as “BD+20 2465”)
Location in Earth sky
g In the constellation Leo
Other names
g AD Leo AD Leonis, 40 Leo, LHS 5167, CNS3 1616, BD+20 2465, G 054-023, SAO 81292, LTT 12761, ADS 7724 C, Vys 574, Yale 2420, Cinc 20C574, GCRV 6499, EUVE J1019+19.8, RE J101935+195212, EXO 1016.8+2007
Sci-fi mentions
g NA
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Saturday, August 11, 2007
Groombridge 1618
Star type
g K7
Distance from Earth
g 15.84 ly
Star Service No.
g NA
Age
g Slightly more than 1 Gy
Diameter/Mass/Temp (xSol)
g 64%; 64%; 4,000 K
Brightness (xSol)
g 4.6% (flare star)
Metallicity
g 191%
Comparison to Sol
g See illustration
Picture of star
g See picture
Star system features
g A flare star with behavior similar to UV Ceti. The chromosphere has been shown to be active and possesses star spots comparable to a Sun spot. It has a greater luminosity than most flare stars, which are typically red dwarfs, but is less active. The level of activity may suggest that this is a somewhat youthful star.
Known planets
g No stellar or brown dwarf companion of at least seven Jupiter masses with an orbital period of less than four years has been detected around the star
Habitable zone
g Distance from Groombridge 1618 where an Earth-type planet would be "comfortable" with liquid water is centered around only 0.22 AU, well within Mercury's orbital distance in the Solar System. At that distance from the star, such a planet would have an orbital period of about 58 days - less than a sixth of an Earth year. The star probably is too young to host a planet with an oxygen-nitrogen atmosphere like Earth's.
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g BD+44 2051 A /WX Ursae Majoris: 3.1 ly
g Struve 1321 AB: 5.2 ly
g GJ 1116 AB: 7.3 ly
g AD Leonis: 8.1 ly
g DX Cancri: 8.2 ly
g Lalande 21185: 8.3 ly
g AC+79 3888: 9 ly
Map locating star system
g See stellar map
Location in Earth sky
g in the northwestern corner of Constellation Ursa Major, the Great Bear, which also encompasses the Big Dipper or Plow (Plough), southwest of Merak (Beta Ursae Majoris), north of Tania Australis and Borealis (Mu and Lambda Ursae Majoris), and east of Talitha (Iota Ursae Majoris
Other names
g GJ 380
g Heintz AJ 94
g BD+50°1725
g GCTP 2390.00
g HD 88230
g HIP 49908
g IRAS 10082+4942
g LFT 696
g LHS 280
g LTT 12732
g SAO 43223
Sci-fi mentions
g Mindbridge (St. Martin's Press, 1978), novel by Joe Haldeman. A planet orbiting Groombridge 1618 serves as the homeworld for the psi-amplifying "Groombridge Bridge" and the L'Vrai race, and is reached by the faster than light system, the "Levant-Meyer Translation"
g Frontier: Elite II and Frontier: First Encounters, computer games. Groombridge 1618 is uninhabited in the Frontier series.
g Revelation Space, novel by Alastair Reynolds. The planet Turqoise, a Pattern Juggler world, orbits Groombridge 1618.
g Among the first 26 interstellar expeditions is one to this star system in Frederick Pohl's short story "Father of the Stars"
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g K7
Distance from Earth
g 15.84 ly
Star Service No.
g NA
Age
g Slightly more than 1 Gy
Diameter/Mass/Temp (xSol)
g 64%; 64%; 4,000 K
Brightness (xSol)
g 4.6% (flare star)
Metallicity
g 191%
Comparison to Sol
g See illustration
Picture of star
g See picture
Star system features
g A flare star with behavior similar to UV Ceti. The chromosphere has been shown to be active and possesses star spots comparable to a Sun spot. It has a greater luminosity than most flare stars, which are typically red dwarfs, but is less active. The level of activity may suggest that this is a somewhat youthful star.
Known planets
g No stellar or brown dwarf companion of at least seven Jupiter masses with an orbital period of less than four years has been detected around the star
Habitable zone
g Distance from Groombridge 1618 where an Earth-type planet would be "comfortable" with liquid water is centered around only 0.22 AU, well within Mercury's orbital distance in the Solar System. At that distance from the star, such a planet would have an orbital period of about 58 days - less than a sixth of an Earth year. The star probably is too young to host a planet with an oxygen-nitrogen atmosphere like Earth's.
Orbital map
g NA
View from star
g See sky map
Nearby stars
(Star systems with 10 light years)
g BD+44 2051 A /WX Ursae Majoris: 3.1 ly
g Struve 1321 AB: 5.2 ly
g GJ 1116 AB: 7.3 ly
g AD Leonis: 8.1 ly
g DX Cancri: 8.2 ly
g Lalande 21185: 8.3 ly
g AC+79 3888: 9 ly
Map locating star system
g See stellar map
Location in Earth sky
g in the northwestern corner of Constellation Ursa Major, the Great Bear, which also encompasses the Big Dipper or Plow (Plough), southwest of Merak (Beta Ursae Majoris), north of Tania Australis and Borealis (Mu and Lambda Ursae Majoris), and east of Talitha (Iota Ursae Majoris
Other names
g GJ 380
g Heintz AJ 94
g BD+50°1725
g GCTP 2390.00
g HD 88230
g HIP 49908
g IRAS 10082+4942
g LFT 696
g LHS 280
g LTT 12732
g SAO 43223
Sci-fi mentions
g Mindbridge (St. Martin's Press, 1978), novel by Joe Haldeman. A planet orbiting Groombridge 1618 serves as the homeworld for the psi-amplifying "Groombridge Bridge" and the L'Vrai race, and is reached by the faster than light system, the "Levant-Meyer Translation"
g Frontier: Elite II and Frontier: First Encounters, computer games. Groombridge 1618 is uninhabited in the Frontier series.
g Revelation Space, novel by Alastair Reynolds. The planet Turqoise, a Pattern Juggler world, orbits Groombridge 1618.
g Among the first 26 interstellar expeditions is one to this star system in Frederick Pohl's short story "Father of the Stars"
Get your SF book manuscript edited
.
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