Summary
ι2 Normae, Latinised as Iota2 Normae, is a single,[9] blue-white star located in the southern constellation of Norma. It is positioned to the west of Rigil Kentaurus but can be difficult to spot against the Milky Way. It is faintly visible to the naked eye with an apparent visual magnitude of +5.57.[2] Measuring its parallax reveals it is located 280±10 light-years away from the sun.[1] At that distance, the visual magnitude is diminished by an interstellar extinction factor of 0.24 due to intervening dust.[10] The radial velocity of this star is zero, indicating it is neither moving toward nor away from the Sun.[4]
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Norma |
| Right ascension | 16h 09m 18.54876s[1] |
| Declination | −57° 56′ 03.5420″[1] |
| Apparent magnitude (V) | 5.57[2] |
| Characteristics | |
| Spectral type | B9.5 V[3] |
| B−V color index | 0.04[2] |
| Astrometry | |
| Radial velocity (Rv) | 0.00±0.37[4] km/s |
| Proper motion (μ) | RA: −13.35±0.48[1] mas/yr Dec.: −59.33±0.46[1] mas/yr |
| Parallax (π) | 11.65 ± 0.57 mas[1] |
| Distance | 280 ± 10 ly (86 ± 4 pc) |
| Absolute magnitude (MV) | +0.91[5] |
| Details[6] | |
| Mass | 2.59 M☉ |
| Radius | 3.1[7] R☉ |
| Luminosity | 40[8] L☉ |
| Surface gravity (log g) | 4.34 cgs |
| Temperature | 10,593±360 K |
| Rotational velocity (v sin i) | 111 km/s |
| Age | 257 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Iota2 Normae is a B-type main-sequence star with a stellar classification of B9.5 V.[3] It is larger than the Sun with 2.6[6] times the mass of the Sun and about 3.1[7] times the Sun's radius. The star is estimated to be 257 million years old and is spinning with a projected rotational velocity of 111 km/s. It is radiating approximately 40 times the Sun's luminosity from its photosphere at an effective temperature of 10,593 Kelvin.[6]
References edit
- ^ a b c d e f van Leeuwen, F. (2007). "Validation of the New Hipparcos Reduction". Astronomy and Astrophysics. 474 (2): 653–64. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
- ^ a b c Lake, R. (1965). "Photometric Magnitudes and Colours for Bright Southern Stars (Sixth List)". Monthly Notes of the Astronomical Society of Southern Africa. 24: 41. Bibcode:1965MNSSA..24...41L.
- ^ a b Houk, N.; Cowley, A. P. (1975). "University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90_ to -53_ƒ0". University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90_ to -53_ƒ0. Bibcode:1975mcts.book.....H.
- ^ a b Kharchenko, N. V.; Scholz, R.-D.; Piskunov, A. E.; Röser, S.; Schilbach, E. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ˜55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. S2CID 119323941.
- ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c 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. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. S2CID 33401607.
- ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental parameters and infrared excesses of Hipparcos stars". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–357. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. S2CID 118665352.
- ^ Chini, R.; et al. (2012), "A spectroscopic survey on the multiplicity of high-mass stars", Monthly Notices of the Royal Astronomical Society, 424 (3): 1925, arXiv:1205.5238, Bibcode:2012MNRAS.424.1925C, doi:10.1111/j.1365-2966.2012.21317.x, S2CID 119120749.
- ^ Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv:1606.09028, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035, S2CID 119108982.
External links edit
- Alcyone page Archived 2016-07-01 at the Wayback Machine