Back سابق (نجم) Arabic Sabik AST Eta del Serpentari Catalan Sabik German Sabik Spanish اتا مارافسای Persian Eta Ophiuchi Finnish Eta Ophiuchi French סביק HE Eta Ophiuchi ID
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 17h 10m 22.68689s[1] |
| Declination | –15° 43′ 29.6639″[1] |
| Apparent magnitude (V) | 2.43[2] (3.05/3.27)[3] |
| Characteristics | |
| Spectral type | A1 IV + A1 IV[3] |
| U−B color index | +0.09[2] |
| B−V color index | +0.05[2] |
| Astrometry | |
| Radial velocity (Rv) | –0.9[4] km/s |
| Proper motion (μ) | RA: +40.13[1] mas/yr Dec.: +99.17[1] mas/yr |
| Parallax (π) | 36.91 ± 0.80 mas[1] |
| Distance | 88 ± 2 ly (27.1 ± 0.6 pc) |
| Orbit[3] | |
| Period (P) | 87.58 ± 1.00 yr |
| Semi-major axis (a) | 1.396 ± 0.010″ |
| Eccentricity (e) | 0.950 ± 0.020 |
| Inclination (i) | 95.2 ± 2.0° |
| Longitude of the node (Ω) | 38.9 ± 1.0° |
| Periastron epoch (T) | 2024.68 ± 0.50 |
| Argument of periastron (ω) (secondary) | 274.8 ± 2.0° |
| η Oph A | |
| Mass | 2.966[3] M☉ |
| Radius | 2.5[5] R☉ |
| Luminosity | 35[5] L☉ |
| Surface gravity (log g) | 3.74[6] cgs |
| Temperature | 8,900[5] K |
| Metallicity | −0.01[6] dex |
| Rotational velocity (v sin i) | 23[7] km/s |
| η Oph B | |
| Mass | 3.478[3] M☉ |
| Radius | 2[5] R☉ |
| Luminosity | 21[5] L☉ |
| Temperature | 8,600[5] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Eta Ophiuchi (η Ophiuchi, abbreviated Eta Oph, η Oph) is a binary star in the constellation of Ophiuchus. Based on parallax measurements taken during the Hipparcos mission, it is approximately 88 light-years from the Sun.
Eta Ophiuchi is part of a multiple star system designated WDS J17104-1544. It itself is designated WDS J17104-1544AB and its two components WDS J17104-1544A (also called Sabik /ˈseɪbɪk/, the traditional name for the system)[8][9] and WDS J17104-1544B. The 'C' component is UCAC4 372-080717[10] and 'D' is UCAC2 26022336.[11]
- ^ a b c d e Cite error: The named reference
aaa474_2_653was invoked but never defined (see the help page). - ^ a b c Hoffleit, D.; Warren, W. H. Jr. (1991). "Entry for HR 2491". Bright Star Catalogue (5th revised (Preliminary Version) ed.). CDS. ID V/50.
- ^ a b c d e Cite error: The named reference
aj133_4_1209was invoked but never defined (see the help page). - ^ Cite error: The named reference
gcsrvwas invoked but never defined (see the help page). - ^ a b c d e f Sabik. stars.astro.illinois.edu. Retrieved July 1, 2024.
- ^ a b Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc--The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
- ^ Cite error: The named reference
aaa463_2_671was invoked but never defined (see the help page). - ^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
- ^ "Naming Stars". IAU.org. Retrieved 27 February 2018.
- ^ "UCAC4 372-080717 -- Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2018-02-27
- ^ "UCAC2 26022336 -- Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2018-02-27
© MMXXIII Rich X Search. We shall prevail. All rights reserved. Rich X Search