30 Ophiuchi

30 Ophiuchi
Location of 30 Ophiuchi (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus
Right ascension 17h 01m 03.60142s[1]
Declination −4° 13′ 21.5308″[1]
Apparent magnitude (V) 4.82[2]
Characteristics
Spectral type K4III[3]
U−B color index +1.80[4]
B−V color index +1.48[4]
Astrometry
Radial velocity (Rv)−6.70[5] km/s
Proper motion (μ) RA: −39.13[6] mas/yr
Dec.: −78.09[6] mas/yr
Parallax (π)9.3138 ± 0.1676 mas[1]
Distance350 ± 6 ly
(107 ± 2 pc)
Absolute magnitude (MV)−0.65[2]
Details
Radius35.89+0.54
−2.12[1] R☉
Luminosity299.8±6.2[1] L☉
Surface gravity (log g)1.73[7] cgs
Temperature4,009.00+126.67
−29.67[1] K
Metallicity [Fe/H]−0.03[2] dex
Rotational velocity (v sin i)1.4[8] km/s
Other designations
30 Oph, NSV 8111, BD−04°4215, FK5 1445, GC 22937, HD 153687, HIP 83262, HR 6318, SAO 141483, CCDM J17011-0413A, WDS J17011-0413A[9]
Database references
SIMBADdata

30 Ophiuchi is a single[10] star in the equatorial constellation of Ophiuchus, and figures 0.99° east (specifically E½S) of the heart of cluster Messier 10.[11] It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.82.[2] The distance to this star is approximately 350 light years based on parallax.[6] Its present motion is, net, one of approaching rather than parting, at −6.7 km/s, its "radial velocity".[5]

This is an aging giant star with a stellar classification of K4III,[3] having exhausted the supply of hydrogen at its core and expanded to 36[1] times the Sun's radius. It is a suspected variable star.[12] The star is radiating 300[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,009 K.[1] It is emitting a far infrared excess due to circumstellar dust,[13] which extends out to a diameter of 240 AU and has a mass of 62×1025 g.[14]

The primary presents with two visual companions: B, at magnitude 9.71 and separation 99.8″, and C, at magnitude 8.75 and separation 220.9″ (3′ 40.9″).[15]

  1. ^ a b c d e f g h i Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference XHIP was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Hoffleit1991 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Mallama2014 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Soubiran2016 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference deMedeiros2014 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference OMeara1998 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Zuckerman1995 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Jura1999 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference WDS was invoked but never defined (see the help page).