V356 Sagittarii

V356 Sagittarii
	; Light curves for V356 Sagittarii, in three photometric bands. Plotted from data published by Wilson and Woodward (1995).
Observation data; Epoch J2000 Equinox J2000
Constellation	Sagittarius
Right ascension	18h 47m 52.331s
Declination	−20° 16′ 28.24″
Apparent magnitude (V)	6.84; Min I: 7.66; Min II: 7.24
Characteristics
Spectral type	B3V + A2II
B−V color index	0.120±0.029
Variable type	Detached Algol(?)
Astrometry
Radial velocity (Rv)	7.0±4.4 km/s
Proper motion (μ)	RA: +0.525 mas/yr ; Dec.: −4.847 mas/yr
Parallax (π)	1.4783 ± 0.0289 mas
Distance	2,210 ± 40 ly ; (680 ± 10 pc)
Orbit
Period (P)	8.896106 d
Eccentricity (e)	0.01566±0.01360
Argument of periastron (ω); (secondary)	288.71851±0.42683°
Semi-amplitude (K1); (primary)	72.17896±1.25080 km/s
Semi-amplitude (K2); (secondary)	190 km/s
Details
Primary
Mass	11.0 M☉
Radius	9.07 R☉
Surface gravity (log g)	3.96±0.10 cgs
Temperature	16,500±750 K
Rotational velocity (v sin i)	350 km/s
Secondary
Mass	3.0 M☉
Radius	13.2 R☉
Surface gravity (log g)	2.82±0.10 cgs
Temperature	8,600±300 K
Rotational velocity (v sin i)	90 km/s
Other designations
	V356 Sgr, BD−20°5268, GC 25739, HD 173787, HIP 92235, SAO 187294, PPM 268914
Database references
SIMBAD	data

V356 Sagittarii is an eclipsing binary star system in the southern constellation of Sagittarius, abbreviated V356 Sgr. It has a peak apparent visual magnitude of 6.84, which decreases to 7.66 during the primary eclipse and 7.24 with the secondary eclipse.^[3] Based on parallax measurements, this system is located at a distance of approximately 2,210 light years from the Sun.^[2]

This is a double-lined spectroscopic binary system with an orbital period of 8.896 days.^[6] It is a massive, interacting system with a circular orbit, where the secondary component has filled its Roche lobe and is transferring matter to its companion. The primary is a B-type main-sequence star with a stellar classification of B3V. It was originally the lower mass component,^[9] but now has about 11 times the mass of the Sun.^[7] The secondary is an evolved supergiant star^[9] with a present-day class of A2II.^[4] It has been stripped of much of its original mass,^[9] leaving behind the exposed core of a star.^[10] The transfer of matter is creating an accretion disk in orbit around the primary.^[9]

At least some of the material stripped from the current secondary component has likely been lost from the system. A relatively small change in the orbital period has been observed, but the period is fairly stable over time, which may mean the mass transfer is intermittent.^[9] Ultraviolet emission has been observed with the FUSE space observatory, indicating the presence of hot circumstellar matter. This emission shows little variation during a total eclipse, suggesting the material lies perpendicular to the accretion disk. This could represent a bipolar jet of matter from the primary.^[11]

References

^ Wilson, R. E.; Woodward, E. J. (February 1995). "U, B, V Light Curves of V356 Sagittarii". Publications of the Astronomical Society of the Pacific. 107: 132–135. Bibcode:1995PASP..107..132W. doi:10.1086/133528. S2CID 121011912. Retrieved 31 March 2023.
^ ^a ^b ^c ^d ^e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
^ ^a ^b ^c Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
^ ^a ^b ^c ^d ^e ^f ^g ^h Polidan, R. S. (June 1988), "A new study of the interacting binary star V356 Sgr", ESA, A Decade of UV Astronomy with the IUE Satellite, vol. 1, pp. 205–208, Bibcode:1988ESASP.281a.205P.
^ ^a ^b Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
^ ^a ^b Cabezas, M.; et al. (February 2017), Miroshnichenko, Anatoly; et al. (eds.), "New Spectroscopic Analysis and Light Curve Model of the Eclipsing Binary V356 Sgr", The B[e] Phenomenon: Forty Years of Studies. Proceedings of a Conference held at Charles University, Prague, Czech Republic 27 June - 1 July 2016, ASP Conference Series, vol. 508, San Francisco: Astronomical Society of the Pacific, p. 364, Bibcode:2017ASPC..508..367C.
^ ^a ^b ^c ^d ^e van Rensbergen, W.; et al. (April 2011), "Mass loss out of close binaries. The formation of Algol-type systems, completed with case B RLOF", Astronomy & Astrophysics, 528, arXiv:1008.2620, Bibcode:2011A&A...528A..16V, doi:10.1051/0004-6361/201015596, S2CID 118417156, A16.
^ "V356 Sgr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-03-29.
^ ^a ^b ^c ^d ^e Lomax, Jamie R.; et al. (January 2017), "The complex circumstellar and circumbinary environment of V356 Sgr", Monthly Notices of the Royal Astronomical Society, 464 (2): 1936–1947, arXiv:1609.07489, Bibcode:2017MNRAS.464.1936L, doi:10.1093/mnras/stw2457.
^ Dominis, D.; et al. (April 2005), "In between β Lyrae and Algol: The Case Of V356 Sgr", Astrophysics and Space Science, 296 (1–4): 189–192, Bibcode:2005Ap&SS.296..189D, doi:10.1007/s10509-005-4443-x, S2CID 121917890.
^ Peters, G. J.; Polidan, R. S. (March 2004), "Eclipse mapping of the hot circumstellar plasma in Algol binaries", Astronomische Nachrichten, 325 (3): 225–228, Bibcode:2004AN....325..225P, doi:10.1002/asna.200310224.

Roby, S. W.; et al. (September 1999), "Abundance determinations and a hot zone model for the interacting binary, V356 Sgr", Bulletin of the Astronomical Society, 31 (4): 1239, Bibcode:1999BAAS...31.1239R, 105.09.
Tomkin, J.; Lambert, D. L. (1994), Shafter, Allen W. (ed.), "V356 Sagittarii – Mass Transfer for the Masses", Interacting binary stars : a symposium held in conjunction with the 105th Meeting of the Astronomical Society of the Pacific, San Diego State University, 13–15 July 1993, vol. 56, San Francisco, Calif: Astronomical Society of the Pacific, p. 397, Bibcode:1994ASPC...56..397T.
Tomkin, Jocelyn; Lambert, David L. (April 1994), "The Carbon Underabundance of the Secondary of V356 Sagittarii", Publications of the Astronomical Society of the Pacific, 106: 365, Bibcode:1994PASP..106..365T, doi:10.1086/133387, S2CID 121742430.
Daly, R. M.; Linnell, A. P. (1992), "A nonsynchronously rotating model for V356 Sagittarii", Bulletin of the Astronomical Society, 24 (3): 1076, Bibcode:1992BAAS...24.1076D.
Polidan, R. S. (June 1989), "500–3200 Å observations of the interacting binary stars V356 Sgr and β Lyr", Space Science Reviews, 50 (1–2): 85–94, Bibcode:1989SSRv...50...85P, doi:10.1007/BF00215921, S2CID 125116416.
Polidan, R. S. (September 1987), "A New Study of the Interacting Binary Star V356 Sgr", Bulletin of the American Astronomical Society, 19: 1085, Bibcode:1987BAAS...19.1085P.
Ziolkowski, J. (1985), "Evolutionary status of V356 Sgr", Acta Astronomica, 35: 199–212, Bibcode:1985AcA....35..199Z.
Ziolkowski, J. (1981), "V356 Sgr revisited", Bulletin of the American Astronomical Society, 13: 924, Bibcode:1981BAAS...13..924Z.
Hall, D. S.; et al. (1981), "A recent time of minimum for V356 Sgr", Acta Astronomica, 31: 383–386, Bibcode:1981AcA....31..383H.
Wilson, R. E.; Caldwell, C. N. (May 1978), "A model of V356 Sagittarii", Astrophysical Journal, 221: 917–925, Bibcode:1978ApJ...221..917W, doi:10.1086/156095.
Popper, Daniel M. (January 1955), "The Eclipsing Binary V356 Sagittarii", Astrophysical Journal, 121: 56, Bibcode:1955ApJ...121...56P, doi:10.1086/145964.
Popper, Daniel M. (1953), "Two eclipsing binaries with giant components", Astronomical Journal, 58: 224–225, Bibcode:1953AJ.....58R.224P, doi:10.1086/106927.
Popper, Daniel M. (October 1950), "Notes on the spectra of eclipsing binaries", Astronomical Journal, 55: 78, Bibcode:1950AJ.....55R..78P, doi:10.1086/106441.