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Fifty Sunlike Stars, from Hipparcos

Submitted by David on Tue, 2006-04-18 03:55

Last Modified: December 17, 2001

Fifty stars from Hipparcos that resemble the Sun. I've chosen them using the following criteria:

  1. Non-variable in Hipparcos data base.
  2. Non-multiple in Hipparcos data base (except very wide doubles)
  3. Main sequence stars with spectral types F6V - K4V
  4. Luminosities between 0.25x and 3x solar (absolute magnitudes 3.6 to 6.35)

Variable stars (possibly excepting short-period eclipsing binaries) are pretty much incompatible with either the development of "native" life or later human colonization. A number of otherwise promising stars are "microvariables", according to the Hipparcos data -- these are marginal (luminosity changes up to about 3%) and I decided to leave them out.

Double and multiple stars posed a bit more of a problem. Really wide doubles (like Zeta Reticuli) are fine, as are many very narrow pairs (those with periods of hours or days, such as most spectroscopic binaries); habitable planets can orbit, respectively, the individual stars or the close pair without much trouble. Unfortunately many visual doubles and multiples fall somewhere between these two extremes. Rather than try to guess where the limits for stable orbits are, I decided to leave them all out, unless their separations were clearly enormous (order of hundreds of AU or more). Unfortunately, this disqualified some otherwise excellent possibilities, including the famous star Alpha Centauri (closest star to the Sun).

Spectral types: confined to main sequence (luminosity class V) since they're the only stars that remain stable for millions (or more) of years. In general, stars hotter than about F5 don't live long enough to provide a good environment for life-bearing worlds, and those cooler than about K5 pose problems with stellar flares and tide-induced rotational locks. Since each spectral type can have a fairly wide range of luminosities, I've made luminosity rather than spectral type the main criterion. Stars near the high end (M_v 3.60; 3x solar luminosity) and the low end (M_v 6.35; 25% solar luminosity) are pretty marginal for developing life or supporting a human planetary colony, but not totally impossible. Optimum for humans, unsurprisingly, is towards the middle of this range, with stars very close to Solar luminosity.

Several of these stars are noteworthy for other reasons.Rho1 Cancri, HR 637, and 47 Ursae Majoris have large (approximately Jupiter sized) planets, as determined from Doppler measurements in the late 1990s. The closest matches to the Sun, judging from absolute magnitude and spectral types, are the fifth-magnitude stars Zeta2 Reticuli, HR 8501, 18 Scorpii, and Nu2 Lupi.

If a star's name is hyperlinked, then it has an entry in the Encyclopedia of Suns, a collection of more detailed information about sunlike stars and their properties, including finder charts for each star. You may click on the star name to view the Encyclopedia entry for it. Be aware that the primary name for each star in the Encyclopedia is often somewhat different from the main name in this list (the Encyclopedia generally uses the Gliese catalogue of nearby stars rather than the HR or HD number).

Star  HIP No.  Other Name  App. Mag.  Abs. Mag.  Spectral Type  Parallax  Distance (l.y.)
 1  8102  Tau Ceti  3.49  5.68  G8V  0.2742  11.9
 2  96100  Sigma Draconis  4.67  5.87  K0V  0.1734  18.8
 3  15510  82 G. Eridani  4.26  5.39  G8V  0.165  19.8
 4  7981  107 Piscium  5.24  5.87  K1V  0.1324  24.3
 5  22449  Pi3 Orionis  3.19  3.69  F6V  0.1246  26.2
 6  89937  Chi Draconis  3.55  4.02  F7Vvar  0.1241  26.3
 7  61317  Beta Canum Venaticorum  4.24  4.67  G0V  0.1195  27.3
 8  64924  61 Virginis  4.74  5.09  G5V  0.1173  27.8
 9  1599  Zeta Tucanae  4.23  4.56  F9V  0.1164  28.0
 10  99825  HR 7722  5.73  6.00  K3V  0.1133  28.7
 11  27072  Gamma Leporis  3.59  3.83  F7V  0.1115  29.2
 12  64394  Beta Coma Berenices  4.23  4.42  G0V  0.1092  29.9
 13  105858  Gamma Pavonis  4.21  4.39  F6V  0.1085  30.0
 14  57443  HR 4523  4.89  5.06  G3/G5V  0.1082  30.1
 15  56452  HR 4458  5.96  6.06  K0V  0.1048  31.1
 16  81300  12 Ophiuchi  5.77  5.82  K2V  0.1023  31.9
 17  8362  HR 511  5.63  5.64  K0V  0.1002  32.5
 18  29271  Alpha Mensae  5.08  5.05  G5V  0.0985  33.1
 19  14632  Iota Persei  4.05  3.98  G0V  0.0949  34.4
 20  117712 HR 9038  6.36  6.20  K3V  0.0934  35.2
21  10644  Delta Trianguli  4.84  4.66  G0V  0.0922  35.4
 22  10138  HR 637  6.21  5.93  K0V  0.0916  35.6
 23  88972  HR 6806  6.38  6.15  K2V  0.0901  36.2
 24  3093  54 Piscium  5.88  5.65  K0V  0.0900  36.2
 25  78072  Gamma Serpentis  3.85  3.62  F6V  0.0899  36.3
 26  12777  Theta Persei  4.10 3.85  F7V  0.0890  36.6
 27  23693  Zeta Doradus  4.71  4.38  F7V  0.0858  38.0
 28  15371  Zeta2 Reticuli  5.24  4.83  G1V  0.0828  39.4
 29  15330  Zeta1 Reticuli  5.53  5.11  G2V  0.0825  39.5
 30  41926  HR 3384  6.38  5.95  K0V  0.0822  39.7
 31  43587  Rho1 Cancri  5.96  5.47  G8V  0.0798  40.9
 32  40693  HR 3259  5.95  5.45  K0V  0.0795  41.0
 33  7918  HR 483  4.96  4.45  G2V  0.0791  41.2
 34  24813  Lambda Aurigae  4.69  4.18  G0V  0.0791  41.2
 35  10798  HR 683  6.33  5.82  G8V  0.0789  41.3
 36  85235  HR 6518  6.44  5.90  K0V  0.0781  41.7
 37  51459  36 Ursae Majoris  4.82  4.28  F8V  0.0778  41.9
 38  91438  HR 6998  5.85  5.28  G5V  0.0770  42.3
 39  90790  HD 170657  6.81  6.21  K1V  0.0757  43.0
 40  110109  HR 8501  5.36  4.69  G1V  0.0735  44.4
 41  16852  10 Tauri  4.29  3.60  F9V  0.0729  44.7
 42  12843  Tau1 Eridani  4.47  3.74  F5/F6V  0.0716  45.5
 43  79672  18 Scorpii  5.49  4.76  G1V  0.0713  45.7
 44  53721  47 Ursae Majoris  5.03  4.29  G0V  0.0710  45.9
 45  79190  HD 144628  7.11  6.33  K3V  0.0697  46.8
 46  78775  HD 144579  6.66  5.87  G8V  0.0696  46.8
 47  84862  72 Herculis  5.38  4.59  G0V  0.0695  46.9
 48  75181  Nu2 Lupi  5.65  4.84  G2V  0.0687  47.5
 49  101997  HR 7898  6.36  5.53  G8/K0V  0.0683  47.7
 50  77052  Psi Serpentis  5.86  5.03  G5V  0.0682  47.8