Astronomy:MY Camelopardalis

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Short description: Binary star system in the constellation Camelopardalis
MY Camelopardalis
MYCamLightCurve.png
A red band light curve for MY Camelopardalis, adapted from Lorenzo et al. (2014)[1]
Observation data
Equinox J2000.0]] (ICRS)
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[7] mas
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 periapsis (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
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. 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. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 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. doi:10.1051/0004-6361/201424345. Bibcode2014A&A...572A.110L. 
  2. 2.0 2.1 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. Bibcode1998A&A...335L..65H. 
  3. 3.0 3.1 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. Bibcode2008IBVS.5863....1K. 
  4. 4.0 4.1 4.2 4.3 Haug, U. (1970). "UBV Observations of luminous stars in three Milky Way fields (Cassiopeia, Camelopardalis and Gemini)". Astronomy & Astrophysics Supplement Series 1 (1): 35. Bibcode1970A&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. Bibcode2004IBVS.5517....1G. 
  6. 6.0 6.1 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27. doi:10.1888/0333750888/2862. Bibcode2000A&A...355L..27H. 
  7. Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.