This list is accurate as of 12 April 2018.
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To be a member of the RECONS 10 Parsec Sample, a star, brown dwarf, or
planet 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 member
of this sample is known to 10% or better.
In the following counts, the Sun is included, and the eight planets in
our Solar System are noted as +8 in various columns. Additions to the
census continue, with a 49% increase in the number of stellar/brown
dwarf systems known within 10 parsecs since 2000. 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 RECONS Census of objects known within 10
parsecs included 293 objects in 213 systems (+8 planets in our Solar
System).
As of January 1, 2010, the RECONS Census of objects known within 10
parsecs included 366 objects in 256 systems (+8 planets in our Solar
System).
As of April 12, 2018, the RECONS Census of objects known within 10
parsecs included 462 objects in 317 systems (+8 planets in our Solar
System). This date is when the summary paper of RECONS discoveries
within 10 parsecs was submitted to The Astronomical Journal, i.e.,
before the Gaia Data Release 2 results became available on April 25,
2018.
RECONS added 43 of the 104 new systems to the census between 2000.0
and 2018.3. An additional system --- GJ 1061 as the 20th nearest ---
was added in 1997, bringing the RECONS total to 44.
Note that the multiplicity rate, or the probability that a given
system has more than one component, is only 27% (85 of 317 systems).
The low rate is because M-type dwarfs (also called red dwarfs) do not
often have companions and dominate the solar neighborhood, accounting
for 284 of the 378 stars within 10 parsecs, or 75% of all stars.
In the table below, companions include stars and brown dwarfs, whereas
planets are listed separately. Planets are not considered in the
numbers of singles, doubles, etc., i.e. the Sun is counted as a single
system, as are single stars with only planets as companions.
The breakdown of objects can be summarized as:
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2000.0 2010.0 2018.3 notes
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total objects 293(+8) 366(+8) 462(+8) 58% increase since 2000
systems 213 256 317 49% increase since 2000
companions 78 97 111 42% increase since 2000 (stars+brown dwarfs)
planets 2(+8) 13(+8) 34(+8) exoplanets (+8 Solar System planets)
singles 153 183 232 planets not considered
doubles 46 54 66
triples 11 15 14
quadruples 2 3 3
quintuples 1 1 2
white dwarfs 18 20 21
O stars 0 0 0
B stars 0 0 0
A stars 4 4 4
F stars 7 7 7
G stars 19 19 19
K stars 44 44 44
M stars 198 246 283 43% increase since 2000
all stars 290 340 378 30% increase since 2000
brown dwarfs 1 13 50
planets 2(+8) 13(+8) 34(+8)
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Note: Additional planets have been reported but not yet fully vetted.