HR 4796

HR 4796

A dust ring encircles HR 4796's primary star
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Centaurus
Right ascension 12h 36m 01.0318s[1]
Declination −39° 52′ 10.2226″[1]
Apparent magnitude (V) 5.80[2]
Characteristics
Spectral type A0 V_+ M2.5 V[3]
B−V color index +0.01[2]
Astrometry
Radial velocity (Rv)9.4[4] km/s
Proper motion (μ) RA: −55.653±0.181[1] mas/yr
Dec.: −23.740±0.230[1] mas/yr
Parallax (π)13.9064 ± 0.1349 mas[1]
Distance235 ± 2 ly
(71.9 ± 0.7 pc)
Absolute magnitude (MV)1.61±0.11[5]
Details
Component A
Mass2.18 ± 0.10[6] M☉
Radius1.68[6] R☉
Luminosity23[6] L☉
Surface gravity (log g)4.43[7] cgs
Temperature9,378[7] K
Metallicity [Fe/H]–0.03[7] dex
Rotational velocity (v sin i)152[8] km/s
Age8 ± 2[3] Myr
Component B
Mass0.3[9] M☉
Other designations
2MASS J12360103-3952102, CCDM J12360-3952, CD-39°7717, CPD-39°5622, GC 17164, HD 109573, HIP 61498, HR 4796, SAO 203621.[10]
Database references
SIMBADdata

HR 4796 is a binary star system in the southern constellation of Centaurus. Parallax measurements put it at a distance of 235 light-years (72 parsecs) from the Earth. The two components of this system have an angular separation of 7.7 arcseconds, which, at their estimated distance, is equivalent to a projected separation of about 560 Astronomical Units (AU), or 560 times the separation of the Earth from the Sun.[3] The star and its ring resemble an eye, and it is sometimes known by the nickname "Sauron's Eye".[11][12]

  1. ^ a b c d e Cite error: The named reference Gaia DR2 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference aj137_1_53 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference apjss169_1_105 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Gerbaldi1999 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference aaas137_273 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference aaa490_1_297 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference aaa463_2_671 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference aaa428_953 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. ^ Flora Graham (4 June 2014). "Eye of Sauron star spotted by planet-hunting camera". New Scientist.
  12. ^ NewsCorp Australia (6 June 2014). "Sauron's Eye has been found. And it's watching us all, from above, in the form of ringed star HR 4796A". Courier Mail.