  | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Crux |
| Right ascension | 12h 54m 39.18258s1 |
| Declination | −59° 08′ 48.1229″1 |
| Apparent magnitude (V) | 4.622 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | B4 Vne3 |
| U−B color index | −0.604 |
| B−V color index | −0.154 |
| Variable type | β Cep?2 |
| Astrometry | |
| Radial velocity (Rv) | +12.0±4.25 km/s |
| Proper motion (μ) | RA: −32.921 mas/yr Dec.: −14.601 mas/yr |
| Parallax (π) | 8.50±0.21 mas1 |
| Distance | 384 ± 9 ly (118 ± 3 pc) |
| Absolute magnitude (MV) | −1.26 |
| Details | |
| Mass | 5.0±0.17 M☉ |
| Radius | 3.008 R☉ |
| Luminosity | 7906 L☉ |
| Surface gravity (log g) | 3.018 cgs |
| Temperature | 16,5008 K |
| Rotational velocity (v sin i) | 2908 km/s |
| Age | 53.3±8.17 Myr |
| Other designations | |
| λ Cru, Lambda Cru, CD−58°4794, HD 112078, HIP 63007, HR 4897, SAO 2403689 | |
| Database references | |
| SIMBAD | data |
λ Crucis, Latinized as Lambda Crucis, is a single,10 variable star in the southern constellation Crux, near the constellation border with Centaurus. It is visible to the naked eye as a faint, blue-white hued point of light with an apparent visual magnitude that fluctuates around 4.62.2 The star is located approximately 384 light-years distant from the Sun based on parallax, and is drifting further away with a radial velocity of +12 km/s.5 It is a proper motion member of the Lower Centaurus–Crux sub-group in the Scorpius–Centaurus OB association, the nearest such association of co-moving massive stars to the Sun.6
λ Crucis is listed in the General Catalogue of Variable Stars as a possible β Cephei-type variable. Its brightness varies with an amplitude of 0m.02 over a period of 0.3951 days.2 However, it is currently thought more likely to be a different type of variable,12 possibly a λ Eridani variable or rotating ellipsoidal variable.1314
This object is a B-type main-sequence star with a stellar classification of B4 Vne,3 where the suffix notation indicates "nebulous" (broad) lines due to rapid rotation, along with emission lines from circumstellar material, making it a Be star.13 It is around 537 million years old and is spinning rapidly with a projected rotational velocity of 341 km/s.15 The star has five7 times the mass of the Sun and about 3.08 times the Sun's radius. It is radiating 7906 times the luminosity of the Sun from its photosphere at an effective temperature of 16,500 K.8
References
References
- van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
- Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869. Retrieved 2019-09-16.
- Levenhagen, R. S.; Leister, N. V. (2006). "Spectroscopic analysis of southern B and Be stars". Monthly Notices of the Royal Astronomical Society. 371 (1): 252–262. arXiv:astro-ph/0606149. Bibcode:2006MNRAS.371..252L. doi:10.1111/j.1365-2966.2006.10655.x. S2CID 16492030.
- Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode:1966CoLPL...4...99J.
- Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. Bibcode:1967IAUS...30...57E.
- de Geus, E. J.; et al. (June 1989). "Physical parameters of stars in the Scorpio-Centaurus OB association". Astronomy and Astrophysics. 216 (1–2): 44–61. Bibcode:1989A&A...216...44D.
- 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. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873.
- Arcos, C.; Kanaan, S.; Chávez, J.; Vanzi, L.; Araya, I.; Curé, M. (2018). "Stellar parameters and H α line profile variability of be stars in the BeSOS survey". Monthly Notices of the Royal Astronomical Society. 474 (4): 5287–5299. arXiv:1711.08675. Bibcode:2018MNRAS.474.5287A. doi:10.1093/mnras/stx3075.
- "lam Cru". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-16.
- Rizzuto, A. C.; et al. (December 2013). "Long-baseline interferometric multiplicity survey of the Sco-Cen OB association". Monthly Notices of the Royal Astronomical Society. 436 (2): 1694–1707. arXiv:1309.3811. Bibcode:2013MNRAS.436.1694R. doi:10.1093/mnras/stt1690.
- "Light Curve". Hipparcos ESA. ESA. Retrieved 18 August 2022.
- Stankov, Anamarija; Handler, Gerald (2005). "Catalog of Galactic β Cephei Stars". The Astrophysical Journal Supplement Series. 158 (2): 193–216. arXiv:astro-ph/0506495. Bibcode:2005ApJS..158..193S. doi:10.1086/429408. S2CID 119526948.
- Balona, L. A. (1995). "Tests of the pulsation and starspot models for the periodic be stars". Monthly Notices of the Royal Astronomical Society. 277 (4): 1547–1554. Bibcode:1995MNRAS.277.1547B. doi:10.1093/mnras/277.4.1547.
- Morris, S. L. (1985). "The ellipsoidal variable stars". The Astrophysical Journal. 295: 143. Bibcode:1985ApJ...295..143M. doi:10.1086/163359.
- Uesugi, Akira; Fukuda, Ichiro (1970). "Catalogue of rotational velocities of the stars". Contributions from the Institute of Astrophysics and Kwasan Observatory. University of Kyoto. Bibcode:1970crvs.book.....U.