Astronomy:4 Lacertae
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Lacerta |
| Right ascension | 22h 24m 30.99149s[1] |
| Declination | +49° 28′ 35.0106″[1] |
| Apparent magnitude (V) | 4.55[2] |
| Characteristics | |
| Evolutionary stage | Blue supergiant (blue loop)[3] |
| Spectral type | A0 Ib[4] |
| B−V color index | 0.092±0.034[2] |
| Astrometry | |
| Radial velocity (Rv) | −26.0±1.7[2] km/s |
| Proper motion (μ) | RA: −5.274(82)[1] mas/yr Dec.: −3.303(96)[1] mas/yr |
| Parallax (π) | 1.2656 ± 0.0891[1] mas |
| Distance | 2,600 ± 200 ly (790 ± 60 pc) |
| Absolute magnitude (MV) | −4.42[5] |
| Details | |
| Mass | 19+13 −8[6] M☉ |
| Radius | 36 ± 5[7][lower-alpha 1] R☉ |
| Luminosity | 17,000+3,000 −2,500[7] L☉ |
| Surface gravity (log g) | 2.18[6] cgs |
| Temperature | 11,000±600[7] K |
| Metallicity [Fe/H] | 0.28±0.04[8] dex |
| Rotational velocity (v sin i) | 28±3[6] km/s |
| Age | 25.1±2.5[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
4 Lacertae is a single[11] blue supergiant star in the northern constellation Lacerta, located about 2,600 light years away.[1] This object visible to the naked eye as a white-hued star with an apparent visual magnitude of 4.55.[2] It is moving closer to the Earth with a heliocentric radial velocity of −26 km/s.[2] This star is a suspected member of the Lac OB1 association.[3][5]
This blue supergiant star has a stellar classification of A0 Ib.[4] The surface abundances show evidence of material that has been processed via the CNO cycle at the core.[3] It has ten[9] times the mass of the Sun and has expanded to about 36 times the Sun's radius.[7][lower-alpha 1] The star is around 25 million years old[9] and is spinning with a projected rotational velocity of 28 km/s.[6][1] It is believed to be a blue loop star that has already spent time as a red supergiant after fusing the hydrogen within its core.
Notes
- ↑ 1.0 1.1 Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
- .
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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.
- ↑ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 3.2 Yüce, Kutluay (2005), "Spectral Analysis of 4 Lacertae and ν Cephei", Baltic Astronomy 14: 51–82, Bibcode: 2005BaltA..14...51Y.
- ↑ 4.0 4.1 Gray, R. O.; Garrison, R. F. (1987), "The Early A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation", The Astrophysical Journal Supplement Series 65: 581, doi:10.1086/191237, Bibcode: 1987ApJS...65..581G.
- ↑ 5.0 5.1 Kaltcheva, Nadia (October 2009), "Lacerta OB1 Revisited", Publications of the Astronomical Society of the Pacific 121 (884): 1045–1053, doi:10.1086/606037, Bibcode: 2009PASP..121.1045K.
- ↑ 6.0 6.1 6.2 6.3 Markova, N.; Puls, J. (2008), "Bright OB stars in the Galaxy. IV. Stellar and wind parameters of early to late B supergiants", Astronomy and Astrophysics 478 (3): 823, doi:10.1051/0004-6361:20077919, Bibcode: 2008A&A...478..823M
- ↑ 7.0 7.1 7.2 7.3 Nurmakhametova, Shakhida T.; Umirova, Aziza B.; Vaidman, Nadezhda L.; Miroshnichenko, Anatoly S.; Khokhlov, Serik A.; Khokhlov, Azamat A.; Agishev, Damir T.; Alimbetova, Dina A. (2026-04-09), "Effective Temperatures of BA-Type Supergiants from SED Fitting" (in en), Galaxies 14 (2): 32, doi:10.3390/galaxies14020032, ISSN 2075-4434.
- ↑ Gáspár, András et al. (2016), "The Correlation between Metallicity and Debris Disk Mass", The Astrophysical Journal 826 (2): 171, doi:10.3847/0004-637x/826/2/171, Bibcode: 2016ApJ...826..171G.
- ↑ 9.0 9.1 9.2 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.
- ↑ "4 Lac". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=4+Lac.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
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