39 Tauri

This article is about A2 Tauri. For other stars with this Bayer designation, see A Tauri.
39 Tauri
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension 04h 05m 20.258s[1]
Declination +22° 00′ 32.06″[1]
Apparent magnitude (V) 5.90[2]
Characteristics
Spectral type G5 V[3]
U−B color index +0.12[4]
B−V color index +0.62[4]
Astrometry
Radial velocity (Rv)+24.0±0.1[5] km/s
Proper motion (μ) RA: +172.212 mas/yr[1]
Dec.: −130.609 mas/yr[1]
Parallax (π)59.4728 ± 0.0361 mas[1]
Distance54.84 ± 0.03 ly
(16.81 ± 0.01 pc)
Details
Mass1.10±0.10[2] M☉
Radius0.96±0.07[2] R☉
Luminosity1.01[2] L☉
Surface gravity (log g)4.52±0.09[2] cgs
Temperature5,903±36[2] K
Metallicity [Fe/H]0.14±0.03[2] dex
Rotation9.12[5] d
Rotational velocity (v sin i)5.52[6] km/s
Age1.0[2] Gyr
Other designations
39 Tau, BD+21 587, GJ 160, HD 25680, HIP 19076, HR 1262, SAO 76438[7]
Database references
SIMBADdata
ARICNSdata

39 Tauri is a binary star in the northern constellation of Taurus. It has an apparent visual magnitude of 5.90, so, according to the Bortle scale, it is faintly visible from suburban skies at night. Measurements made with the Hipparcos spacecraft show an annual parallax shift of 0.0594728″, which is equivalent to a distance of around 55 light years from the Sun.

A light curve for 39 Tauri, plotted from Kepler (K2) data[8]

39 Tauri has been resolved into a pair of stars using speckle interferometry.[9] However, many observations have failed to resolve the secondary star.[10]

A stellar classification of G5 V[3] matches that of a G-type main sequence star; the type of the secondary component is unknown. Stellar models indicate the primary component is similar in physical properties to the Sun, with 110% of the Sun's mass, 96% of the radius, and shining with almost the same luminosity.[2] The overall metallicity of the star—the abundance of elements other than hydrogen and helium—is similar to the Sun.[11] At a relatively youthful estimated age of one billion years,[2] it is rotating with a period of 9.12[5] days. Based upon Hipparcos data, it displays a mild variability with an amplitude of 0.06 magnitude.[12]

The space velocity components of 39 Tauri are: –25.0(U), –14.0(V), –6.0(W). The surface activity and kinematic properties of this star are consistent with membership in the IC 2391 moving group.[13] It is following an orbit through the Milky Way galaxy that has an eccentricity of 0.06 carrying it as close as 23.9 kly (7.34 kpc) to the Galactic Center, and as far away as 26.8 kly (8.21 kpc). The orbital inclination will carry the star no further than 33 ly (10 pc) away from the galactic plane.[11]

  1. ^ a b c d Cite error: The named reference GaiaEDR3 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h i j Cite error: The named reference Ghezzi2010 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Shenavrin2011 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference LópezSantiago2010 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference MartínezArnáiz2010 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference hartkopf2009 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Roberts2005 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Casagrande2011 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Adelman2000 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Murgas2013 was invoked but never defined (see the help page).