MY Camelopardalis

"MY Cam" redirects here. For the iOS app, see My Cam.
MY Camelopardalis
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Camelopardalis
Right ascension 03h 59m 18.2863s[1]
Declination +57° 14 13.673[1]
Apparent magnitude (V) 9.80 - 10.15[2]
Characteristics
Spectral type O6nn[3] (O6V((f)) + O6V((f))[4])
U−B color index 0.66[3]
B−V color index +0.28[3]
Variable type Ellipsoidal[2]
Astrometry
Radial velocity (Rv)47[5] km/s
Proper motion (μ) RA: 2.3[6] mas/yr
Dec.: 0.3[6] mas/yr
Distance~4,000[5] pc
Absolute magnitude (MV)4.1[3]
Orbit[5]
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[5]
Mass37.7 M
Radius7.60 R
Surface gravity (log g)4.251 cgs
Mass31.6 M
Radius7.01 R
Surface gravity (log g)4.245 cgs
Other designations
MY Camelopardalis, BD+56°864, Alicante 1 NM 693, 2MASS J03591829+5714137
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.[7] MY Cam is the brightest star in Alicante 1.[8]

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.[9] 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 (620,000 mph).[7] They were likely formed 2 million years ago.

The system is anticipated to merge to form a single massive star of about 60 solar masses. This is expected to be the way that most extremely massive single stars are formed.[7]

When originally discovered, the system was considered to be a single variable star and not a binary system.[7] Its binary nature was only discerned in 2004.[8]

References

  1. 1 2 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.
  2. 1 2 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.
  3. 1 2 3 4 Haug, U. (1970). "UBV Observations of luminous stars in three Milky Way fields (Cassiopeia, Camelopardalis and Gemini)". Astronomy & Astrophysics Supplement Series Vol. 1 1: 35. Bibcode:1970A&AS....1...35H.
  4. 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.
  5. 1 2 3 4 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.
  6. 1 2 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.
  7. 1 2 3 4 Andrew Fazekas (9 December 2014). "Astronomers Spy Monster Star Merger on the Move".
  8. 1 2 Asociación RUVID (5 December 2014). "Astronomers observe two stars so close to each other that they will end up merging into a supermassive star". ScienceDaily.
  9. "Astronomers observe two stars so close to each other that they will end up merging into a supermassive star". Phys.org. 6 December 2014. Retrieved 6 December 2014.
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