MY Camelopardalis

MY Camelopardalis

A red band light curve for MY Camelopardalis, adapted from Lorenzo et al. (2014)[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Camelopardalis
Right ascension 03h 59m 18.2863s[2]
Declination +57° 14′ 13.673″[2]
Apparent magnitude (V) 9.80 - 10.15[3]
Characteristics
Spectral type O6nn[4] (O6V((f)) + O6V((f))[5])
U−B color index −0.66[4]
B−V color index +0.28[4]
Variable type Ellipsoidal[3]
Astrometry
Radial velocity (Rv)−47[1] km/s
Proper motion (μ) RA: −2.3[6] mas/yr
Dec.: −0.3[6] mas/yr
Parallax (π)0.1333 ± 0.0789 mas[7]
Distance~4,000[1] pc
Absolute magnitude (MV)−4.1[4]
Orbit[1]
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
Details[1]
A
Mass37.7 M☉
Radius7.60 R☉
Surface gravity (log g)4.251 cgs
Temperature42,000 ± 1,500 K
Rotational velocity (v sin i)290 km/s
B
Mass31.6 M☉
Radius7.01 R☉
Surface gravity (log g)4.245 cgs
Temperature39,000 ± 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
SIMBADdata

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

  1. ^ a b c d e f g h 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.
  2. ^ a b 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.
  3. ^ a b 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.
  4. ^ a b c d 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.
  5. ^ 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.
  6. ^ a b 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.
  7. ^ 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.
  8. ^ 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.
  9. ^ 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.
  10. ^ 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.