This list is accurate as of 01 January 2008.
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To be a member of the RECONS sample, a star (and any attending
companions) must have a trigonometric parallax of 100 milliarcseconds
or more, and an error in that parallax of less than 10
milliarcseconds. This parallax corresponds to a distance of 10
parsecs, or 32.6 light years. The error requirement means that the
distance to every RECONS sample member is known to 10% or better.
In the following counts, the Sun is included, but the eight planets in
our Solar System are not. Brown dwarfs as well as planets orbiting
other stars are included in the counts. Additions to the census
continue. Occasional deletions also occur, when reported objects do
not stand up to further scrutiny. Only results published in refereed
journals are included in the counts.
As of January 1, 2000, the complete RECONS Census of objects known
within 10 parsecs included 295 objects in 215 systems.
As of January 1, 2008, the complete RECONS Census of objects known
within 10 parsecs included 354 objects in 249 systems.
To date, RECONS has added 28 of the 34 new systems to the census since
2000. An additional system --- GJ 1061 as the 20th nearest --- was
added in 1997, bringing the RECONS total to 29.
Note that the multiplicity rate, or the probability that a given
system has more than one component, is only 31%. The low rate is
because M-type dwarfs (also called red dwarfs) dominate the solar
neighborhood (a full 72% of the stellar sample, i.e. not L/T/P
objects, are M-type dwarfs), and do not have companions as often as
their more massive stellar cousins.
The breakdown of objects can be summarized as:
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2000.0 2005.0 2008.0 notes
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total objects 295 309 354 20% increase since 2000
systems 215 221 249 16% increase since 2000
companions 80 88 105 31% increase since 2000
singles 153 154 171
doubles 48 51 58
triples 11 12 14
quadruples 2 3 5
quintuples 1 1 1
WDs 18 18 18 white dwarfs
Os 0 0 0
Bs 0 0 0
As 4 4 4
Fs 6 6 6
Gs 21 21 21
Ks 44 44 44
Ms 199 204 239 20% increase since 2000
Ls 0 2 4
Ts 1 7 8
Ps 2 3 10 1 planet around GJ 144 (epsilon Eri)
1 planet around GJ 176
3 planets around GJ 581
1 planet around GJ 674
1 planet around GJ 849
3 planets around GJ 876
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Note: Planet counts are as reported, although not all may be confirmed.
For questions or comments, please contact Dr. Todd J. Henry at thenry@chara.gsu.edu