36 Serpentis

This article is about b Serpentis. Not to be confused with β (Beta) Serpentis.
36 Serpentis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Serpens
Right ascension 15h 51m 15.59418s[1]
Declination −03° 05′ 25.7938″[1]
Apparent magnitude (V) 5.09[2] (5.2 + 7.8)[3]
Characteristics
Spectral type A3Vn[4] or A2IV-Vn[5] (A7 + G0)[6]
U−B color index +0.07[7]
B−V color index +0.12[7]
Astrometry
Radial velocity (Rv)−8[8] km/s
Proper motion (μ) RA: −91.09[1] mas/yr
Dec.: −28.21[1] mas/yr
Parallax (π)20.10 ± 0.33 mas[1]
Distance162 ± 3 ly
(49.8 ± 0.8 pc)
Absolute magnitude (MV)1.61[2]
Orbit[6]
Period (P)50.6±1.5 yr
Semi-major axis (a)0.400±0.006″
Eccentricity (e)0.8323±0.0047
Inclination (i)98.08±0.31°
Longitude of the node (Ω)74.00±0.31°
Periastron epoch (T)2002.78±0.17
Argument of periastron (ω)
(secondary)		72.84±0.91°
Details
36 Ser A
Mass2.04[9] M☉
Radius1.65[10] R☉
Luminosity19.13[2] L☉
Surface gravity (log g)3.89[11] cgs
Temperature8246[11] K
Metallicity [Fe/H]−2.00[11] dex
Rotational velocity (v sin i)229[12] km/s
Age723[9] Myr
Other designations
b Ser, 36 Ser, BD−02°4058, FK5 2249, GC 4210, HD 141851, HIP 77660, HR 5895, SAO 140801, WDS J15513-0305[13]
Database references
SIMBADdata

36 Serpentis is a binary star[14] system in the equatorial constellation of Serpens. It has the Bayer designation b Serpentis, while 36 Serpentis is the Flamsteed designation.[13] The system is visible to the naked eye as a dim, white-hued point of light with a combined apparent visual magnitude of 5.09.[2] It is located 162 light years away from the Sun based on parallax,[1] and is moving closer with a radial velocity of −8 km/s.[8]

This is a spectroscopic binary star system with a long orbital period of 52.8 years and a high eccentricity of 0.83. The combined mass of the pair is 3.09±0.28 M☉.[6] Gray et al. (2017) found a merged stellar classification of A2IV-Vn for this system,[5] while Cowley et al. matched it with a class of A3Vn,[4] where the 'n' indicates "nebulous" lines caused by rapid rotation.

The primary component is a Lambda Boötis star, meaning that it has solar-like amounts of carbon, nitrogen, and oxygen, while containing very low amounts of iron peak elements.[15] It is an A7[6] class main sequence star of visual magnitude 5.2[3] that is spinning rapidly, showing a projected rotational velocity of 229.[12] The star is 723[9] million years old with around double the mass of the Sun. It is radiating 19[2] times the Sun's luminosity from its photosphere at an effective temperature of 8,246 K.[11]

The cooler secondary component, a G0 star,[6] is the source for the X-ray emission that has been detected coming from this system.[6] It has a visual magnitude of 7.8.[3]

  1. ^ a b c d e f Cite error: The named reference HIP was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference orbit was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Cowley1969 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gray2017 was invoked but never defined (see the help page).
  6. ^ a b c d e f Cite error: The named reference Mason2010 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference UBV was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference GCRV was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference David2015 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference CADARS was invoked but never defined (see the help page).
  11. ^ a b c d Cite error: The named reference MILES was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference Royer was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Nikolov was invoked but never defined (see the help page).