Astronomy:5 Lacertae
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Short description: Star in the constellation Lacerta
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Lacerta[1] |
| Right ascension | 22h 29m 31.823s[2] |
| Declination | +47° 42′ 24.79″[2] |
| Apparent magnitude (V) | 4.36[3] |
| Characteristics | |
| Spectral type | K6–M0I + B7/8V[4] |
| U−B color index | +1.11[3] |
| B−V color index | +1.68[3] |
| Variable type | LC[5] |
| Astrometry | |
| Radial velocity (Rv) | −3.4±0.2[6] km/s |
| Proper motion (μ) | RA: −2.554[7] mas/yr Dec.: −5.372[7] mas/yr |
| Parallax (π) | 1.4838 ± 0.1383[7] mas |
| Distance | 2,170+200 −180 ly (665+62 −54 pc) |
| Absolute magnitude (MV) | −4.16[1] |
| Orbit[6] | |
| Period (P) | 41.95±0.20 yr |
| Eccentricity (e) | 0.49±0.01 |
| Periastron epoch (T) | 2427578.3±260 JD |
| Argument of periastron (ω) (secondary) | 323±5.0° |
| Semi-amplitude (K1) (primary) | 12.2±1.2 km/s |
| Semi-amplitude (K2) (secondary) | 112.0±8.2 km/s |
| Details | |
| 5 Lacertae A | |
| Mass | 5.11±0.18[8] M☉ |
| Radius | 427+36 −44[9] R☉ |
| Luminosity | 25,100[10][lower-alpha 1] L☉ |
| Temperature | 3,790[10][lower-alpha 2] K |
| Rotational velocity (v sin i) | 50[11] km/s |
| Age | 110±10[8] Myr |
| 5 Lacertae B | |
| Rotational velocity (v sin i) | 89[3] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
5 Lacertae (5 Lac) is a spectroscopic binary in the constellation Lacerta. Its apparent magnitude is 4.36.
Variability
5 Lacertae is a slow irregular variable star with a small amplitude. Photometry from the Hipparcos satellite showed brightness changes between Hipparcos magnitudes 4.39 and 4.56 with no clear periodicity.[5] It was given the variable star designation V412 Lacertae in 1999 in a special name-list dedicated to variables detected from Hipparcos.[14]
Characteristics
The spectrum of 5 Lacertae clearly indicates both a hot component and a cooler component, recognised even in early spectra. Published spectral types for the brighter cool component vary from K4 to M0, with a luminosity class of giant or supergiant. The hotter star is generally classed as a relatively unevolved late B or early A star, but an automated classification program gave it a spectral class of B2V.[15]
Radial velocity variations in the absorption lines from the two separate stars have been measured to determine the orbit. This has an unusually long period of almost 42 years. The two stars have an eccentric orbit with a projected axis of about 15 au.[6]
Notes
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.
- ↑ 2.0 2.1 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
- ↑ 3.0 3.1 3.2 3.3 Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H 5050. Bibcode: 1995yCat.5050....0H.
- ↑ Pantaleoni González, M.; Maíz Apellániz, J.; Barbá, R. H.; Negueruela, I. (2020-01-01). "A Catalog of Galactic Multiple Systems with a Red Supergiant and a B Star". Research Notes of the American Astronomical Society 4 (1): 12. doi:10.3847/2515-5172/ab712b. ISSN 2515-5172. Bibcode: 2020RNAAS...4...12P.
- ↑ 5.0 5.1 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. Originally Published in: 2009yCat....102025S 1. Bibcode: 2009yCat....102025S.
- ↑ 6.0 6.1 6.2 Hendry, E. M. (1978). "Observations of a second maximum for the very long period spectroscopic binary 5 Lac". Publications of the Astronomical Society of the Pacific 90: 184–187. doi:10.1086/130304. Bibcode: 1978PASP...90..184H.
- ↑ 7.0 7.1 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.
- ↑ 8.0 8.1 Baines, Ellyn K. et al. (2018). "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer". The Astronomical Journal 155 (1): 30. doi:10.3847/1538-3881/aa9d8b. Bibcode: 2018AJ....155...30B.
- ↑ Baines, Ellyn K.; Clark, James H.; Kingsley, Bradley I.; Schmitt, Henrique R.; Stone, Jordan M. (2025-05-07). "Vintage NPOI: New and Updated Angular Diameters for 145 Stars" (in en). The Astronomical Journal 169 (6): 293. doi:10.3847/1538-3881/adc930. ISSN 1538-3881. Bibcode: 2025AJ....169..293B.
- ↑ 10.0 10.1 Healy, Sarah; Horiuchi, Shunsaku; Molla, Marta Colomer; Milisavljevic, Dan; Tseng, Jeff; Bergin, Faith; Weil, Kathryn; Tanaka, Masaomi (2024-03-23). "Red Supergiant Candidates for Multimessenger Monitoring of the Next Galactic Supernova". Monthly Notices of the Royal Astronomical Society 529 (4): 3630–3650. doi:10.1093/mnras/stae738. ISSN 0035-8711.
- ↑ Van Belle, Gerard T (2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review 20 (1): 51. doi:10.1007/s00159-012-0051-2. Bibcode: 2012A&ARv..20...51V.
- ↑ "5 Lacertae". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=5+Lacertae.
- ↑ "Hipparcos Tools Interactive Data Access". ESA. https://www.cosmos.esa.int/web/hipparcos/interactive-data-access.
- ↑ Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (1999). "The 74th Special Name-list of Variable Stars". Information Bulletin on Variable Stars 4659 (4659): 1. Bibcode: 1999IBVS.4659....1K.
- ↑ Skiff, B. A. (2014). "VizieR On-line Data Catalog: Catalogue of Stellar Spectral Classifications". VizieR On-line Data Catalog. Bibcode: 2014yCat....1.2023S.
<ref> tag with name "b-j" defined in <references> is not used in prior text.
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