Astronomy:Kappa1 Apodis
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Apus[1] |
| Right ascension | 15h 31m 30.82213s[2] |
| Declination | −73° 23′ 22.5295″[2] |
| Apparent magnitude (V) | 5.52[3] |
| Characteristics | |
| Spectral type | B1npe[4] + sdO[5] |
| U−B color index | −0.791[3] |
| B−V color index | −0.128[3] |
| Variable type | γ Cas[6] |
| Astrometry | |
| Radial velocity (Rv) | +62[7] km/s |
| Proper motion (μ) | RA: +0.996[2] mas/yr Dec.: −18.345[2] mas/yr |
| Parallax (π) | 3.0798 ± 0.0717[2] mas |
| Distance | 1,060 ± 20 ly (325 ± 8 pc) |
| Absolute magnitude (MV) | −2.47[1] |
| Orbit[8] | |
| Period (P) | 192.1±0.1 d |
| Semi-major axis (a) | ≥ 288.3±8.4 R☉ |
| Eccentricity (e) | 0 (assumed) |
| Inclination (i) | 60±4° |
| Periastron epoch (T) | 2458401.9±2.2 HJD |
| Semi-amplitude (K1) (primary) | 9.09±0.08 km/s |
| Semi-amplitude (K2) (secondary) | 66.87±1.84 km/s |
| Details | |
| A | |
| Mass | 11.8±1.0[8] M☉ |
| Radius | 5.45±0.29[5] R☉ |
| Luminosity | 2,120[1] L☉ |
| Surface gravity (log g) | 3.90[9] cgs |
| Temperature | 21,500[9] K |
| Rotational velocity (v sin i) | 250[5] km/s |
| Age | 5.6±1.0[10] Myr |
| B | |
| Mass | 1.60±0.14[8] M☉ |
| Radius | 0.44±0.06[5] R☉ |
| Luminosity | 446[5] L☉ |
| Temperature | 40,000[5] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Kappa1 Apodis is a binary star[4] system in the southern circumpolar constellation of Apus.[1] Its idetifier is a Bayer designation that is Latinized from κ1 Apodis, and abbreviated Kap1 Aps or κ1 Aps, respectively. Based upon parallax measurements, it is located roughly 1,060 light-years (325 parsecs) from Earth. The combined apparent visual magnitude of the system is 5.52,[3] indicating that this is a faint, naked eye star that can be viewed in dark suburban skies. It is moving away from the Sun with a radial velocity of +62 km/s.[7]
This is a spectroscopic binary system, made up of a Be star and a subdwarf O star, which complete an orbit around each other every 192 days.[8] The combined spectrum matches a stellar classification of B1npe.[4] The 'e' suffix indicates that this is a Be star with emission lines in the spectrum. An 'n' means that the absorption lines in the spectrum are broadened from the Doppler effect as a result of rapid rotation. Finally, the 'p' shows some peculiarity in the spectrum. It is classified as a Gamma Cassiopeiae type variable star and its brightness varies from magnitude +5.43 to +5.61.
This is a runaway star with a peculiar velocity of 69.8±4.7 km/s.[10] Because it is a binary star system, it was most likely not turned into a runaway system as the result of a supernova explosion.[4]
A 12th-magnitude orange K-type subgiant[13] located at an angular separation of 27 arcseconds has a much smaller parallax than Kappa1 Apodis and is a distant background object.[14]
References
- ↑ 1.0 1.1 1.2 1.3 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 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 Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement 15: 459, doi:10.1086/190168, Bibcode: 1968ApJS...15..459G.
- ↑ 4.0 4.1 4.2 4.3 Jilinski, E. et al. (September 2010), "A Dynamical Study of Suspected Runaway Stars as Traces of Past Supernova Explosions in the Region of the Scorpius-Centaurus OB Association", The Astrophysical Journal 721 (1): 469–477, doi:10.1088/0004-637X/721/1/469, Bibcode: 2010ApJ...721..469J.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Wang, Luqian et al. (2021), "The Detection and Characterization of Be+sdO Binaries from HST/STIS FUV Spectroscopy", The Astronomical Journal 161 (5): 248, doi:10.3847/1538-3881/abf144, Bibcode: 2021AJ....161..248W.
- ↑ Samus, N. N. et al. (2009), "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)", VizieR On-line Data Catalog: B/GCVS 1: 02025, Bibcode: 2009yCat....102025S.
- ↑ 7.0 7.1 Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, 30, University of Toronto: International Astronomical Union, p. 57, Bibcode: 1967IAUS...30...57E.
- ↑ 8.0 8.1 8.2 8.3 Wang, Luqian et al. (April 2023), "The Orbital and Physical Properties of Five Southern Be+sdO Binary Systems" (in en), The Astronomical Journal 165 (5): 203, doi:10.3847/1538-3881/acc6ca, ISSN 1538-3881, Bibcode: 2023AJ....165..203W.
- ↑ 9.0 9.1 Soubiran, C. et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, doi:10.1051/0004-6361/201014247, Bibcode: 2010A&A...515A.111S.
- ↑ 10.0 10.1 Tetzlaff, N. et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T.
- ↑ "HR 5730". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HR+5730.
- ↑ MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html, retrieved 8 December 2021.
- ↑ Gahm, G. F.; Ahlin, P.; Lindroos, K. P. (1983), "A study of visual double stars with early type primaries. I. Spectroscopic results", Astronomy and Astrophysics Supplement Series 51: 143, Bibcode: 1983A&AS...51..143G.
- ↑ 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.
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