| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Camelopardalis |
| Right ascension | 03h 59m 18.2863s2 |
| Declination | +57° 14′ 13.673″2 |
| Apparent magnitude (V) | 9.80 - 10.153 |
| Characteristics | |
| Spectral type | O6nn4 (O6V((f)) + O6V((f))5) |
| U−B color index | −0.664 |
| B−V color index | +0.284 |
| Variable type | Ellipsoidal3 |
| Astrometry | |
| Radial velocity (Rv) | −471 km/s |
| Proper motion (μ) | RA: −2.36 mas/yr Dec.: −0.36 mas/yr |
| Parallax (π) | 0.1333±0.0789 mas7 |
| Distance | ~4,0001 pc |
| Absolute magnitude (MV) | −4.14 |
| Orbit1 | |
| Period (P) | 1.175 days |
| Semi-major axis (a) | 19.24 R☉ |
| Eccentricity (e) | 0 |
| Inclination (i) | 62.59° |
| Argument of periastron (ω) (secondary) | 90° |
| Argument of periastron (ω) (primary) | 270° |
| Semi-amplitude (K1) (primary) | 335 km/s |
| Semi-amplitude (K2) (secondary) | 400 km/s |
| Details1 | |
| A | |
| Mass | 37.7 M☉ |
| Radius | 7.60 R☉ |
| Surface gravity (log g) | 4.251 cgs |
| Temperature | 42,000 ± 1,500 K |
| Rotational velocity (v sin i) | 290 km/s |
| B | |
| Mass | 31.6 M☉ |
| Radius | 7.01 R☉ |
| Surface gravity (log g) | 4.245 cgs |
| Temperature | 39,000 ± 1,500 K |
| Rotational velocity (v sin i) | 268 km/s |
| Other designations | |
| MY Camelopardalis, BD+56°864, Alicante 1 NM 693, 2MASS J03591829+5714137, Gaia DR2 469715181320008960, TYC 3725-498-1 | |
| Database references | |
| SIMBAD | data |
MY Camelopardalis (MY Cam) is a binary star system located in the Alicante 1 open cluster, some 13 kly (4.0 kpc) away in the constellation Camelopardalis. It is one of the most massive known binary star systems and a leading candidate for a massive star merger. MY Cam is the brightest star in Alicante 1.1
The system consists of two hot blue O-type stars with one component having a mass of 32 solar masses and the other 38 solar masses.
In 1998, the star was included in a list of suspected variable stars.8 John Greaves and Patrick Wils proved that it is variable, in 2004.9 It was given its variable star designation, MY Camelopardalis, in 2008.10 MY Cam is a contact binary and eclipsing binary, with an orbital period of 1.2 days, and an orbital velocity of 1,000,000 km/h (280 km/s; 620,000 mph).1 Both stars share a common envelope.1
References
References
- Lorenzo, J.; Negueruela, I.; Val Baker, A. K. F.; García, M.; Simón-Díaz, S.; Pastor, P.; Méndez Majuelos, M. (2014). "MY Camelopardalis, a very massive merger progenitor". Astronomy & Astrophysics. 572: A110. arXiv:1410.5575v1. Bibcode:2014A&A...572A.110L. doi:10.1051/0004-6361/201424345. S2CID 53743637.
- Hog, E.; Kuzmin, A.; Bastian, U.; Fabricius, C.; Kuimov, K.; Lindegren, L.; Makarov, V. V.; Roeser, S. (1998). "The TYCHO Reference Catalogue". Astronomy and Astrophysics. 335: L65. Bibcode:1998A&A...335L..65H.
- Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2008). "The 79th Name-List of Variable Stars". Information Bulletin on Variable Stars. 5863: 1. Bibcode:2008IBVS.5863....1K.
- Haug, U. (1970). "UBV Observations of luminous stars in three Milky Way fields (Cassiopeia, Camelopardalis and Gemini)". Astronomy & Astrophysics Supplement Series. 1 (1): 35. Bibcode:1970A&AS....1...35H.
- Greaves, John; Wils, Patrick (2004). "NSV 15852 is likely an Elliptical Variable akin in type to AO Cas". Information Bulletin on Variable Stars. 5517: 1. Bibcode:2004IBVS.5517....1G.
- Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862.
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V. (December 1998). "New Catalogue of Suspected Variable Stars. Supplement - Version 1.0" (PDF). Information Bulletin on Variable Stars. 4655: 1–4. Bibcode:1998IBVS.4655....1K. Retrieved 30 December 2024.
- Greaves, John; Wils, Patrick (April 2004). "NSV 15852 is likely an Elliptical Variable akin in type to AO Cas" (PDF). Information Bulletin on Variable Stars. 5517: 1–2. Retrieved 30 December 2024.
- Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (November 2008). "The 79th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 5863: 1–16. Bibcode:2008IBVS.5863....1K. Retrieved 30 December 2024.