Zeta Ophiuchi

ζ Ophiuchi
Location of ζ Oph (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus
Right ascension 16h 37m 09.54001s[1]
Declination −10° 34′ 01.5097″[1]
Apparent magnitude (V) 2.56 – 2.58[2]
Characteristics
Spectral type O9.5 V[3]
U−B color index −0.857[4]
B−V color index +0.032[4]
Variable type γ Cas[2] + β Cep[3]
Astrometry
Radial velocity (Rv)−15.0[5] km/s
Proper motion (μ) RA: +10.465 mas/yr[1]
Dec.: +24.742 mas/yr[1]
Parallax (π)7.4088 ± 0.6596 mas[1]
Distance440 ± 40 ly
(130 ± 10 pc)[1]
Absolute magnitude (MV)−4.2[6]
Details
Mass20.2[7] M☉
Radius9.1 (equator)
7.5 (polar)[6] R☉
Luminosity74,100[7] L☉
Surface gravity (log g)3.58[6] cgs
Temperature30,700 (equatorial)
39,000 (polar)[6] K
Rotational velocity (v sin i)400[3] km/s
Age3.0±0.3[8] Myr
Other designations
13 Oph, BD−10°4350, FK5 622, HD 149757, HIP 81377, HR 6175, SAO 160006, 2MASS J16370954-1034014, Gaia DR2 4337352305315545088
Database references
SIMBADdata

Zeta Ophiuchi (ζ Oph, ζ Ophiuchi) is a single[9] star located in the constellation of Ophiuchus. It has an apparent visual magnitude of 2.6, making it the third-brightest star in the constellation. Parallax measurements give an estimated distance of roughly 440 light-years (130 parsecs) from the Earth.[1] It is surrounded by the Sh2-27 "Cobold" nebula, the star's bow shock as it ploughs through dense dust clouds near the Rho Ophiuchi cloud complex.

In April 2010, ζ Ophiuchi was occulted by asteroid 824 Anastasia.[10][11][12]

  1. ^ a b c d e f Cite error: The named reference DR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference gcvs was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference an332_2_147 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference sbpes1984 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference scfs was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference rotational was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference repolust was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference mnras410_1_190 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Hutter was invoked but never defined (see the help page).
  10. ^ "Asteroid To Hide Naked-Eye Star". Sky & Telescope. 31 March 2010. Archived from the original on 20 July 2012. Retrieved 20 November 2022.
  11. ^ "Asteroid To Hide Bright Star". Archived from the original on 5 May 2010. Retrieved 17 July 2019.
  12. ^ "(824) Anastasia / HIP 81377 event on 2010 Apr 06, 10:21 UT". Archived from the original on 17 July 2019. Retrieved 17 July 2019.