Astronomy:Iota2 Cygni
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 19h 29m 42.36s[2] |
| Declination | +51° 43′ 47.2″[2] |
| Apparent magnitude (V) | 3.76[1] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | A5V[4] |
| B−V color index | +0.148±0.001[1] |
| Astrometry | |
| Radial velocity (Rv) | −19.5±2.7[1] km/s |
| Proper motion (μ) | RA: +20.59[2] mas/yr Dec.: +128.33[2] mas/yr |
| Parallax (π) | 26.88 ± 0.11[2] mas |
| Distance | 121.3 ± 0.5 ly (37.2 ± 0.2 pc) |
| Absolute magnitude (MV) | +0.91[1] |
| Details | |
| Mass | 1.80[5] M☉ |
| Radius | 3.83+0.40 −0.36[6] R☉ |
| Luminosity | 34.5±0.5[6] L☉ |
| Surface gravity (log g) | 3.91[5] cgs |
| Temperature | 8,216±279[5] K |
| Rotational velocity (v sin i) | 240[3] km/s |
| Age | 577[5] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Iota2 Cygni is a single[8] star in the constellation Cygnus. Its name is a Bayer designation that is Latinized from ι2 Cygni, and abbreviated Iota2 Cyg or ι2 Cyg, albeit it is often just called ι Cyg.[9] It is visible to the naked eye as a white-hued point of light with an apparent visual magnitude of 3.76.[1] Located around 121.3 light-years distant from the Sun based on parallax,[2] it is drifting closer with a radial velocity of −19.5 km/s and is expected to come to within 92 light-years in around 783,000 years.[1]
This it is an A-type main-sequence star with a stellar classification of A5V,[4] a star that is currently fusing its core hydrogen. It is around 577 million years old[5] and is spinning rapidly with a projected rotational velocity of 240 km/s.[3] The star has 1.8 times the mass of the Sun[5] and 3.8 times the Sun's radius.[6] It is radiating 35 times the luminosity of the Sun[6] from its photosphere at an effective temperature of 8,216 K.[5] Based on rapid changes in the strength of a singly-ionized calcium absorption line, the star is likely host to a circumstellar disk.[10]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 van Leeuwen, F. (November 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.
- ↑ 3.0 3.1 3.2 Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics 537: A120, doi:10.1051/0004-6361/201117691, Bibcode: 2012A&A...537A.120Z.
- ↑ 4.0 4.1 Chesneau, O. et al. (2010). "Time, spatial, and spectral resolution of the Hα line-formation region of Deneb and Rigel with the VEGA/CHARA interferometer". Astronomy and Astrophysics 521: A5. doi:10.1051/0004-6361/201014509. Bibcode: 2010A&A...521A...5C. https://hal.archives-ouvertes.fr/hal-00501515.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D.
- ↑ 6.0 6.1 6.2 6.3 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ "iot02 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=iot02+Cyg.
- ↑ 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
- ↑ Kaler, Jim. "Kappa, Iota Cygni". STARS. http://stars.astro.illinois.edu/sow/kappacyg.html.
- ↑ Montgomery, Sharon L.; Welsh, Barry Y. (October 2012). "Detection of Variable Gaseous Absorption Features in the Debris Disks Around Young A-type Stars". Publications of the Astronomical Society of the Pacific 124 (920): 1042–1056. doi:10.1086/668293. Bibcode: 2012PASP..124.1042M.
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