Astronomy:Iota Coronae Borealis
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Corona Borealis[1] |
| Right ascension | 16h 01m 26.56492s[2] |
| Declination | +29° 51′ 03.8194″[2] |
| Apparent magnitude (V) | 4.96[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | A0 IIIp(HgMnEu)s[4] |
| U−B color index | −0.15[3] |
| B−V color index | −0.06[3] |
| Astrometry | |
| Radial velocity (Rv) | −20.8±0.4[5] km/s |
| Proper motion (μ) | RA: −38.817[2] mas/yr Dec.: −7.016[2] mas/yr |
| Parallax (π) | 8.7701 ± 0.0857[2] mas |
| Distance | 372 ± 4 ly (114 ± 1 pc) |
| Absolute magnitude (MV) | +0.08[1] |
| Orbit[6] | |
| Period (P) | 35.474 d |
| Eccentricity (e) | 0.56 |
| Periastron epoch (T) | 2441566.96 JD |
| Argument of periastron (ω) (secondary) | 156° |
| Semi-amplitude (K1) (primary) | 2.3 km/s |
| Details | |
| ι CrB A | |
| Mass | 3.16±0.04[2] M☉ |
| Radius | 3.93+0.06−0.07[2] R☉ |
| Luminosity | 159±3[2] L☉ |
| Surface gravity (log g) | 3.68±0.01[2] cgs |
| Temperature | 7,601+11−8[2] K |
| Metallicity [Fe/H] | −0.01±0.12[7] dex |
| Rotational velocity (v sin i) | 18[8] km/s |
| Age | 273±32[2] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Iota Coronae Borealis is a binary star[6] system in the northern constellation of Corona Borealis. It has the proper name Aurwandilsta;[10] Iota Coronae Borealis is its Bayer designation, which is Latinized from ι Coronae Borealis and abbreviated Iota CrB or ι CrB. This system is visible to the naked eye as a point of light with an apparent visual magnitude of 4.96.[3] Based upon an annual parallax shift of 8.77 mas as seen from the Earth,[2] it is located about 372 light years from the Sun.
This is a single-lined spectroscopic binary with an orbital period of 35.5 days and an eccentricity of 0.56.[6] The visible member, component A, has a stellar classification of A0 IIIp(HgMnEu)s,[4] indicating it is a chemically peculiar mercury-manganese star with narrow absorption lines. This star has an estimated age of approximately 273 million[2] years and is spinning with a projected rotational velocity of 18 km/s.[7] It has 3.3 times the mass and 3.9 times the radius of the Sun. The star is radiating 159 times the luminosity of the Sun from its photosphere at an effective temperature of 7,601 K.[2] The secondary member, component B, appears to be an A-type star.[11]
Aurwandils tá, "Aurvandill's Toe", is an old Norse constellation identified with Corona Borealis. The IAU Working Group on Star Names adopted the name Aurwandilsta for Iota Coronae Borealis A on 14 May 2026.[10]
References
- ↑ 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 Fernie, J. D. (1983), "New UBVRI photometry for 900 supergiants", Astrophysical Journal Supplement Series 52: 7, doi:10.1086/190856, Bibcode: 1983ApJS...52....7F.
- ↑ 4.0 4.1 Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement 99: 135, doi:10.1086/192182, Bibcode: 1995ApJS...99..135A.
- ↑ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ 6.0 6.1 6.2 Pourbaix, D. et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy and Astrophysics 424 (2): 727–732, doi:10.1051/0004-6361:20041213, Bibcode: 2004A&A...424..727P.
- ↑ 7.0 7.1 Prugniel, Ph. et al. (July 2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics 531: A165, doi:10.1051/0004-6361/201116769, Bibcode: 2011A&A...531A.165P.
- ↑ Royer, F. et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics 393: 897–911, doi:10.1051/0004-6361:20020943, Bibcode: 2002A&A...393..897R.
- ↑ "iot CrB". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=iot+CrB.
- ↑ 10.0 10.1 "IAU Catalog of Star Names". https://exopla.net/star-names/modern-iau-star-names/.
- ↑ Dubaj, D. et al. (December 2005), "Abundance determinations for the two components of the spectroscopic binary star HD143807", SF2A-2005: Semaine de l'Astrophysique Française (EdP-Sciences): 335, Bibcode: 2005sf2a.conf..335D.
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