Astronomy:Iota Ophiuchi
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 16h 54m 00.47151s[1] |
| Declination | 10° 09′ 55.2982″[1] |
| Apparent magnitude (V) | 4.39[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B8V[4] |
| U−B color index | −0.32[5] |
| B−V color index | −0.08[5] |
| Astrometry | |
| Radial velocity (Rv) | −19.0±1.6[6] km/s |
| Proper motion (μ) | RA: −53.80[1] mas/yr Dec.: −34.04[1] mas/yr |
| Parallax (π) | 13.30 ± 0.22[1] mas |
| Distance | 245 ± 4 ly (75 ± 1 pc) |
| Absolute magnitude (MV) | 0.01[2] |
| Details | |
| Mass | 3.14±0.03[3] M☉ |
| Radius | 2.8[7] R☉ |
| Luminosity | 141+6 −5[3] L☉ |
| Surface gravity (log g) | 4.03[8] cgs |
| Temperature | 11,220±78[3] K |
| Metallicity [Fe/H] | +0.09[8] dex |
| Rotational velocity (v sin i) | 124[3] km/s |
| Age | 217[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
ι Ophiuchi, Latinized as Iota Ophiuchi, is a single[11] star in the equatorial constellation of Ophiuchus, positioned near the constellation border with Hercules. It makes a naked-eye double with nearby Kappa Ophiuchi,[12] appearing as a faint, blue-white hued star with an apparent visual magnitude of 4.39.[2] The star is approximately 245 light years from the Sun based on parallax,[1] but is drifting closer with a radial velocity of −19 km/s.[6]
This object is a B-type main-sequence star with a stellar classification of B8V.[4] It is an estimated 217[9] million years old with a moderately high rate of spin, showing a projected rotational velocity of 124 km/s.[3] The star has 3.1[3] times the mass of the Sun and around 2.8[7] times the Sun's radius. Iota Ophiuchi is radiating 141[3] times the luminosity of the Sun from its photosphere at an effective temperature of 11,220 K.[3] It displays an infrared excess, suggesting the presence of circumstellar material.[13]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. Vizier catalog entry
- ↑ 2.0 2.1 2.2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. Vizier catalog entry
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars". Astronomy & Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode: 2012A&A...537A.120Z. Vizier catalog entry
- ↑ 4.0 4.1 Cowley, A. (November 1972). "Spectral classification of the bright B8 stars". Astronomical Journal 77: 750–755. doi:10.1086/111348. Bibcode: 1972AJ.....77..750C.
- ↑ 5.0 5.1 Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers 42 (2): 443. Bibcode: 2014JAVSO..42..443M.Vizier catalog entry
- ↑ 6.0 6.1 Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode: 2006AstL...32..759G.
- ↑ 7.0 7.1 Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics 352: 555–562. Bibcode: 1999A&A...352..555A. Vizier catalog entry
- ↑ 8.0 8.1 Wu, Yue et al. (2010). "Coudé-feed stellar spectral library – atmospheric parameters". Astronomy & Astrophysics 525: A71. doi:10.1051/0004-6361/201015014. Bibcode: 2011A&A...525A..71W.
- ↑ 9.0 9.1 Gontcharov, G. A. (November 2012). "Spatial distribution and kinematics of OB stars". Astronomy Letters 38 (11): 694–706. doi:10.1134/S1063773712110035. Bibcode: 2012AstL...38..694G.
- ↑ "iot Oph". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=iot+Oph.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society 389 (2): 869–879. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.
- ↑ Arnold, H. J. P. et al. (1999). The Photographic Atlas of the Stars. CRC Press. p. 156. ISBN 9780750306546. https://books.google.com/books?id=YjcvJUfnWBAC&pg=PA156.
- ↑ McDonald, I. et al. (2012). "Fundamental parameters and infrared excesses of Hipparcos stars". Monthly Notices of the Royal Astronomical Society 427 (1): 343–357. doi:10.1111/j.1365-2966.2012.21873.x. Bibcode: 2012MNRAS.427..343M.
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