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SY Muscae

SY Muscae

A visual band light curve for SY Muscae, plotted from ASAS and ASAS-SN data.[1][2] The inset plot shows the same data plotted with respect to the phase of the orbital period.
Observation data
Epoch J2000      Equinox J2000
Constellation Musca
Right ascension 11h 32m 10.0002s[3]
Declination −65° 25′ 11.473″[3]
Apparent magnitude (V) 10.2 (- 11.2) - 12.7[4]
Characteristics
Spectral type M4.5[5]
Variable type Z And[4]
Astrometry
Radial velocity (Rv)+13.708[5] km/s
Parallax (π)0.08 ± 0.90 mas[3]
Distance1,500[5] pc
Orbit[5]
Period (P)624.36 days
Eccentricity (e)0.0
Inclination (i)84°
Semi-amplitude (K1)
(primary)		7.76 km/s
Details
Giant
Mass1.5[5] M☉
Radius114[5] R☉
Luminosity1,556[5] L☉
Temperature3,400[5] K
Rotational velocity (v sin i)7[5] km/s
White dwarf
Mass0.50[5] M☉
Other designations
SY Muscae, HD 100336, IRAS 11299-6508, 2MASS J11320998-6525114
Database references
SIMBADdata

SY Muscae is a binary star system in the constellation Musca composed of a red giant and a white dwarf.[6] Its apparent magnitude varies from 10.2 to 12.7 over a period of 624.5 days.[7] Although the binary is a symbiotic star system, it is unusual in that it does not have an eruptive component.[6] It is an S-type symbiotic system, which means that the light comes from the stars rather than surrounding dust.[8]

In 1914, it was announced that Annie Jump Cannon had discovered that the star is a variable star, from the examination of nine photographs taken from 1896 through 1905.[9] It was given its variable star designation, SY Muscae, in 1925.[10]

With optical spectrometry, the red giant has been calculated as having a surface temperature of 3500 K and spectral type M4.5III, with around 1.3 times the Sun's mass, 86 times its radius and 1000 times its luminosity. The white dwarf is only 0.43 times the mass of the Sun. The two stars are 1.72 astronomical units (AU) apart, and take 624 days to orbit each other.[6] The red giant also pulsates with a period of 56 days.[8] The surface of the giant star extends to 40% of the distance to the Lagrange point L1, and hence does not fill its Roche Lobe and cause the white dwarf to gain an accretion disc. The system was calculated at being around 850 parsecs (2771 light-years) distant.[6]

References

  1. ^ "ASAS All Star Catalogue". The All Sky Automated Survey. Retrieved 8 December 2021.
  2. ^ "ASAS-SN Variable Stars Database". ASAS-SN Variable Stars Database. ASAS-SN. Retrieved 6 January 2022.
  3. ^ a b c Gaia Collaboration; Brown, A. G. A; Vallenari, A; Prusti, T; De Bruijne, J. H. J; Mignard, F; Drimmel, R; Babusiaux, C; Bailer-Jones, C. A. L; Bastian, U; Biermann, M; Evans, D. W; Eyer, L; Jansen, F; Jordi, C; Katz, D; Klioner, S. A; Lammers, U; Lindegren, L; Luri, X; O'Mullane, W; Panem, C; Pourbaix, D; Randich, S; Sartoretti, P; Siddiqui, H. I; Soubiran, C; Valette, V; Van Leeuwen, F; et al. (2016). "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties". Astronomy & Astrophysics. 595: A2. arXiv:1609.04172. Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512. S2CID 1828208.
  4. ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  5. ^ a b c d e f g h i j Fekel, Francis C; Hinkle, Kenneth H; Joyce, Richard R; Wood, Peter R (2017). "Infrared Spectroscopy of Symbiotic Stars. XI. Orbits for Southern S-type Systems: Hen 3-461, SY Mus, Hen 3-828, AND AR Pav". The Astronomical Journal. 153 (1): 35. Bibcode:2017AJ....153...35F. doi:10.3847/1538-3881/153/1/35.
  6. ^ a b c d Schmutz, W.; Schild, H.; Muerset, U.; Schmid, H.M. (1994). "High resolution spectroscopy of symbiotic stars I. SY Muscae: orbital elements, M giant radius, distance". Astronomy and Astrophysics. 288: 819–28. Bibcode:1994A&A...288..819S.
  7. ^ Otero, Sebastian Alberto (13 March 2013). "SY Muscae". AAVSO Website. American Association of Variable Star Observers. Retrieved 9 March 2014.
  8. ^ a b Gromadzki, M.; Mikołajewska, J.; Soszyński, I. (2013). "Light Curves of Symbiotic Stars in Massive Photometric Surveys II. S and D'-Type Systems". Acta Astronomica. 63 (4): 405–28. arXiv:1312.6063. Bibcode:2013AcA....63..405G.
  9. ^ Cannon, Annie J.; Pickering, Edward C. (September 1914). "Stars Having Peculiar Spectra". Harvard College Observatory Circular. 184: 1–3. Bibcode:1914HarCi.184....1C. Retrieved 19 December 2024.
  10. ^ Guthnick, P.; Prager, R. (March 1925). "Benennung von neu entdeckten veränderlichen Sternen". Astronomische Nachrichten. 224 (8): 129–146. Bibcode:1925AN....224..129G. doi:10.1002/asna.19252240802. Retrieved 19 December 2024.
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