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| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
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extrasolar planets
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The existence of giant planets in sub-Mercurian orbits (see epistellar jovians) and in highly elongated orbits (see eccentric jovians) has come as a surprise and forced theorists to revise their understanding of how young planetary systems evolve (see planetary systems, formation). The challenge now is to develop more sensitive techniques capable of finding Earth-class planets, especially those in orbit within the habitable zones of their host stars. These are potentially the most important worlds in the search for life, although, as in the case of Europa and Callisto, large moons of giant planets may also prove to be biologically interesting.
The discovery of (a) extrasolar planets around roughly 12% of the target stars searched (remembering that many lower mass worlds around these stars almost certainly await detection), (b) a planetary system in the case of upsilon Andromedae, and (c) circumstellar disks around stars of widely differing spectral type, has led to heightened optimism that planetary systems are common throughout the Universe. However, some researchers have urged caution. In 1997, Guillermo Gonzalez of the University of Washington, Seattle, and his colleagues, pointed out1 that almost all of the stars around which planets have been detected to date are richer in heavy elements than is the Sun (see heavy element concentration, related to the occurrence of planets). The relative scarcity of such stars might imply strict limits, too, on the numbers of planetary systems. Moreover, argued Gonzalez, the phenomenon of inward orbital migration which might account for the presence of giant planets in orbits close to their host stars would tend to scatter any terrestrial planets that had formed between the migrating planet and the star, resulting in a dearth of Earthlike worlds.2 The next decade should see a clarification of such issues.
The table below lists those extrasolar planets confirmed as of Oct. 19, 2002, in order of increasing distance from their host stars. See individual entries for further information on each object. A separate table is provided for pulsar planets.
Related categories
• PLANETS AND MOONS
• ASTROBIOLOGY
References
- Gonzalez, G., and Vanture, A. "Parent Stars of Extrasolar Planets III: Rho1 Cancri Revisited," Astronomy & Astrophysics, 334, 221 (1998).
- Gonzalez, G. "Extrasolar Planets and ETI," Astronomy & Geophysics, 39, 68 (1998).
- Black, D. "Completing the Copernican Revolution: The Search for Other Planetary Systems," Annual Review of Astronomy and Astrophysics, 33, 359 (1995).
- Boss, Alan, "Forming a Jupiter-like Companion for 51 Peg," Lunar and Planetary Science, 27, 139 (1996).
- Clark, Stuart. Extrasolar Planets, London: Wiley (1999).
- Croswell, Ken. Planet Quest: The Epic Discovery of Alien Solar Systems. New York: Free Press (1997).
- Goldsmith, Donald. Worlds Unnumbered: The Search for Extrasolar Planets. Sausalito, Calif.: University Science Books (1997).
- Halpern, Paul. The Quest for Alien Planets. New York: Plenum (1997).
- Marcy, G. W. "Extrasolar Planets," Nature, 391, 127 (1998).
Host Star |
Planets |
Dist. from Earth |
Mag. |
Planet Mass |
14 Herculis b |
55.42 |
6.67 |
3.3 |
|
70 |
6.2 |
1.5 |
||
227.5 |
5 |
|||
43 |
5.1 |
2.41 |
||
0.76 |
||||
48 |
5.5 |
0.47 |
||
44 |
5.95 |
0.84 |
||
0.21 |
||||
4.05 |
||||
18 (Earth=1) |
||||
59 |
5 |
6.6 |
||
10 |
0.48 |
|||
10.4 |
3.73 |
0.86 |
||
0.1 |
||||
38.5 |
3.225 |
1.76 |
||
57 |
6.59 |
3.31 |
||
30 |
10.68 |
0.067 |
||
20.5 |
10.55 |
17 (Earth=1) |
||
51.8 |
5.71 |
1.15 |
||
18.1 (Earth=1) |
||||
36 |
6.17 |
4 |
||
15 |
10.17 |
> 1.89 |
||
0.56 |
||||
7.5 (Earth=1) |
||||
500 |
12 |
0.75 |
||
99 |
8.21 |
0.18 |
||
0.3 |
||||
94 |
8.05 |
0.48 |
||
332.5 |
5.8 |
6.3 |
||
122 |
7.36 |
6.81 |
||
56.4 |
5.52 |
1.17 |
||
97.8 |
6.292 |
6.59 |
||
126 |
6.99 |
0.34 |
||
223.31 |
8.76 |
1.65 |
||
|
||||
94.5 |
7.61 |
7.8 |
||
91.28 |
8.8 |
0.99 |
||
114 |
6.69 |
0.9 |
||
72 |
7.57 |
0.99 |
||
107 |
7.3 |
2.06 |
||
123 |
7.18 |
0.16 |
||
145 |
7.54 |
0.89 |
||
121 |
7.44 |
2.83 |
||
1.66 |
||||
54 |
7.51 |
2.63 |
||
3.21 |
||||
98 |
8.05 |
1.08 |
||
81 |
6.45 |
1.58 |
||
170 |
6.9 |
11.9 |
||
109 |
7.25 |
9.7 |
||
67 |
5.7 |
1.36 |
||
116.6 |
7.7 |
4.4 |
||
111.5 |
7.34 |
1.62 |
||
42 |
5.376 |
1 |
||
256 |
8.15 |
0.36 |
||
88.7 |
7.029 |
1 |
||
222 |
7.25 |
1.8 |
||
49 |
5.15 |
1.97 |
||
1 |
||||
14 (Earth=1) |
||||
117 |
6.78 |
0.215 |
||
101.9 |
9.18 |
13.75 |
||
107 |
6.92 |
7.2 |
||
17.1 |
||||
141 |
7.95 |
0.24 |
||
118 |
5.9 |
2.96 |
||
4.04 |
||||
192 |
7.175 |
1.28 |
||
152 |
7.98 |
6.292 |
||
88 |
6.254 |
0.84 |
||
172 |
7.86 |
3.69 |
||
153 |
7.79 |
0.52 |
||
171 |
8.22 |
1.26 |
||
149 |
7.43 |
1.14 |
||
63 |
7.7 |
1.15 |
||
215 |
7.3 |
4.99 |
||
65 |
8.1 |
0.72 |
||
65 |
6.91 |
3.43 |
||
152 |
7.6 |
3 |
||
73 |
5.07 |
2 |
||
150 |
8.8 |
2.44 |
||
88 |
6.4 |
1.07 |
||
292.7 |
9.01 |
5.1 |
||
145.8 |
7.48 |
0.41 |
||
153 |
7.65 |
0.69 |
||
72 |
6.63 |
1.28 |
||
133 |
6.8 |
3.7 |
||
135 |
6.064 |
2.1 |
||
124 |
8.1 |
0.7 |
||
121 |
6.16 |
1.28 |
||
2.1 |
||||
146 |
4.21 |
2.9 |
||
137 |
7.7 |
5.4 |
||
113 |
7.1 |
2.54 |
||
169.5 |
7.24 |
7.19 |
||
175 |
9.44 |
0.48 |
||
59 |
4.442 |
1.43 |
||
137.7 |
9.36 |
0.62 |
||
128 |
7.81 |
5.7 |
||
179 |
8.41 |
7.7 |
||
163.6 |
9 |
0.8 |
||
124 |
7.06 |
7.71 |
||
35.7 |
5.8 |
|
||
107 |
7.68 |
1.04 |
||
1.01 |
||||
0.66 |
||||
139.8 |
8.69 |
2.84 |
||
138 |
5.94 |
0.77 |
||
11.3 |
||||
67 |
5.67 |
10.37 |
||
107.58 |
6.75 |
3.16 |
||
138.5 |
8.65 |
2.3 |
||
252 |
8.68 |
1.64 |
||
110 |
7.79 |
0.81 |
||
159 |
7.88 |
0.98 |
||
109 |
7.94 |
0.249 |
||
400 |
5.261 |
> 4.96 |
||
132.7 |
8.35 |
0.12 |
||
101 |
6.86 |
4.9 |
||
91 |
6.3 |
1.13 |
||
299 |
5.45 |
6.5 |
||
116.3 |
9.37 |
0.38 |
||
131 |
7.72 |
0.48 |
||
111.8 |
8.62 |
1.21 |
||
189 |
8.21 |
1.9 |
||
94.5 |
7.18 |
2 |
||
163 |
7.48 |
2.55 |
||
119 |
8.08 | 1.85 |
||
322.74 |
9 |
3 |
||
210 |
7.62 |
1.56 |
||
> 7.5 |
||||
94.3 |
6.35 |
0.42 |
||
194.6 |
8.13 |
0.197 |
||
58.38 |
8.93 |
3.41 |
||
106 |
7.74 |
6.86 |
||
89 |
6.54 |
1.63 |
||
0.88 |
||||
142 |
8.23 |
0.35 |
||
144 |
7.8 |
2.23 |
||
241.4 |
8 |
0.29 |
||
130 |
5.7 |
7.2 |
||
107 |
7.31 |
3.8 |
||
97 |
8.3 |
0.37 |
||
58.5 |
7.57 |
0.122 |
||
50.5 |
5.4 |
2.26 |
||
100 |
3.3 |
8.7 |
||
17000 |
> 1.5 |
|||
21000 |
5.5 (Earth=1) |
|||
15000 |
> 3 |
|||
4875 |
0.53 |
|||
4890 |
14.42 |
1.35 |
||
4890 |
15.72 |
1.01 |
||
5000 |
16.6 |
0.9 |
||
978 |
|
|||
|
||||
|
||||
|
||||
55 |
5.4 |
1.1 |