Upsilon Serpentis

Upsilon Serpentis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Serpens
Right ascension 15h 47m 17.31882s[1]
Declination +14° 06′ 55.2617″[1]
Apparent magnitude (V) +5.70[2]
Characteristics
Spectral type A3 V[3]
U−B color index +0.09[2]
B−V color index +0.10[2]
Astrometry
Radial velocity (Rv)−34.2±2.9[4] km/s
Proper motion (μ) RA: −55.49[1] mas/yr
Dec.: +32.42[1] mas/yr
Parallax (π)13.04 ± 0.84 mas[1]
Distance250 ± 20 ly
(77 ± 5 pc)
Absolute magnitude (MV)+1.30[5]
Details
Mass2.9±0.23[6] M☉
Radius2.2[7] R☉
Luminosity23[8] L☉
Surface gravity (log g)4.0±0.14[6] cgs
Temperature8,917±303[6] K
Rotational velocity (v sin i)133[9] km/s
Age403+70
−75[6] Myr
Other designations
υ Ser, 31 Serpentis, BD+14° 2939, HD 141187, HIP 77336, HR 5870, SAO 101739[10]
Database references
SIMBADdata

Upsilon Serpentis, Latinized from υ Serpentis, is a star in the Serpens Caput section of the constellation Serpens. Based upon an annual parallax shift of 13.04 mas as seen from Earth, it is located around 250 light years from the Sun. The star is bright enough to be faintly visible to the naked eye, having an apparent visual magnitude of +5.70.[2] It is a member of the Hyades group, a stream of stars that share a similar trajectory to the Hyades cluster.[11]

This is an A-type main sequence star with a stellar classification of A3 V.[3] It has an estimated 2.9[6] times the mass of the Sun and around 2.2[7] times the Sun's radius. With an age of 403[6] million years, it has a high rate of spin with a projected rotational velocity of 133 km/s.[9] It is radiating 23[8] times the solar luminosity from its photosphere at an effective temperature of 8,917 K.[6]

Upsilon Serpentis is a suspected astrometric binary,[12] which means an undetected companion is perturbing the motion of the visible star. An X-ray emission has been detected from this system with a luminosity of 247.8×1020 W. This may be coming from the companion, since A-type stars are not expected to emit X-rays.[13]

  1. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Cowley1969 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b c d e f g Cite error: The named reference Kraus2016 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Royer2007 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggen1982 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Schroeder2007 was invoked but never defined (see the help page).