Epsilon Serpentis

ε Serpentis
Location of ε Serpentis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Serpens
Right ascension 15h 50m 48.96622s[1]
Declination +04° 28′ 39.8311″[1]
Apparent magnitude (V) +3.69[2]
Characteristics
Spectral type kA2hA5mA7 V[3]
U−B color index +0.12[2]
B−V color index +0.14[2]
Astrometry
Radial velocity (Rv)−9.4±0.6[4] km/s
Proper motion (μ) RA: +128.19[1] mas/yr
Dec.: +62.16[1] mas/yr
Parallax (π)46.30 ± 0.19 mas[1]
Distance70.4 ± 0.3 ly
(21.60 ± 0.09 pc)
Absolute magnitude (MV)+2.04[5]
Details
Mass1.820±0.026[6] M☉
Radius1.783±0.040[6] R☉
Luminosity12.134±0.296[6] L☉
Surface gravity (log g)4.346[7] cgs
Temperature7,928±88[7] K
Metallicity [Fe/H]+0.38[7] dex
Rotational velocity (v sin i)33.1[7] km/s
Age500±200[6] Myr
Other designations
ε Ser, 37 Serpentis, BD+04°3069, HD 141795, HIP 77622, HR 5892, SAO 121218[8]
Database references
SIMBADdata

Epsilon Serpentis, Latinized from ε Serpentis, is a single,[9] white-hued star in the constellation Serpens, in its head (Serpens Caput). It is visible to the naked eye with an apparent visual magnitude of +3.69.[2] Based upon an annual parallax shift of 46.30 mas as seen from Earth,[1] it is located 70 light years from the Sun. It is moving closer to the Sun with a radial velocity of −9 km/s.[4]

This is an Am star[10] on the main-sequence with a stellar classification of kA2hA5mA7 V.[3] This notation indicates the spectrum displays the calcium K-line of an A2 star, the hydrogen lines of an A5 star, and the metal lines of an A7 star.[11] It has been examined for the presence of a magnetic field, but the detected level was not statistically significant.[12]

Epsilon Serpentis has an estimated 1.82 times the mass of the Sun and 1.78 times the Sun's radius.[6] The star is radiating 12[6] times the Sun's luminosity from its photosphere at an effective temperature of around 7,928 K.[7] It is a candidate for an infrared excess at a wavelength of 25 μm, suggesting a circumstellar disk of dust with a temperature of 250±70 K may be orbiting roughly 4.2 AU from the host star.[13] The star is around half[6] a billion years old and is spinning with a projected rotational velocity of 33.1 km/s.[7]

  1. ^ a b c d e f 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 feinstein1974 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  4. ^ a b 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 Boyajian2012 was invoked but never defined (see the help page).
  7. ^ a b c d e f Cite error: The named reference David2015 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Rodriguez2015 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Adelman1998 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Walker2017 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Shorlin2002 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Smith2010 was invoked but never defined (see the help page).