V4199 Sagittarii

V4199 Sagittarii is a variable star in the southern constellation of Sagittarius.^[8] It is a dim star that is just visible to the naked eye with an apparent visual magnitude that varies between 6.22 and 6.28 over a period of 1.23825 days.^[9] The star is located at a distance of approximately 689 light years from the Sun based on parallax, but is drifting closer with a radial velocity of roughly −23 km/s.^[6] It has an absolute magnitude of −0.63,^[3] on average.

V4199 Sagittarii

A light curve for V4199 Sagittarii, plotted from Hipparcos data[1]
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Sagittarius
Right ascension	19h 21m 37.11363s[2]
Declination	−19° 14′ 04.0500″[2]
Apparent magnitude (V)	6.25[3]
Characteristics
Spectral type	B5III[4]
B−V color index	−0.091±0.004[3]
Variable type	SPB[5]
Astrometry
Radial velocity (Rv)	−23.3±7.4[6] km/s
Proper motion (μ)	RA: +3.135 mas/yr Dec.: −12.136 mas/yr
Parallax (π)	4.7371 ± 0.0556 mas[2]
Distance	689 ± 8 ly (211 ± 2 pc)
Absolute magnitude (MV)	−0.63[3]
Details[5]
Mass	4.2±0.3 M☉
Radius	2.9±0.5 R☉
Luminosity	316+82 −66 L☉
Surface gravity (log g)	4.16±0.20 cgs
Temperature	14,700±700 K
Rotational velocity (v sin i)	6±4 km/s
Age	48.9±21.6[7] Myr
Other designations
173 G. Sagittarii, BD−19°5412, HD 181558, HIP 95159, HR 7339, SAO 162511, WDS 19216-1914[8]
Database references
SIMBAD	data

The stellar classification of this star is B5III,^[4] matching a B-type giant star. In the Bright Star Catalogue it was listed as a main sequence star of class B5V, although the colors suggest a somewhat more evolved star.^[10] The photometric variability of this star was announced by C. Waelkens and F. Rufener in 1984.^[11] It is a multi-periodic^[10] slowly pulsating B star with a dominant frequency of 0.80780±0.00010 cycles/day.^[12] The star has four times the mass of the Sun and three times the Sun's radius. It is radiating ~316 times the luminosity of the Sun from its photosphere at an effective temperature of 14,700 K. A magnetic field has been detected on this star with a strength of −104±32 G.^[5]

It has a magnitude 9.96 companion star at an angular separation of 90.9″ along a position angle of 310°, as of 2003.^[13]

References

1. "Light Curve". Hipparcos ESA. ESA. Retrieved 17 February 2022.
2. 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.
3. 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.
4. Houk, Nancy; Smith-Moore, M. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 4. Ann Arbor: Dept. of Astronomy, University of Michigan. Bibcode:1988mcts.book.....H.
5. Hubrig, S.; et al. (April 2009). "New magnetic field measurements of β Cephei stars and slowly pulsating B stars". Astronomische Nachrichten. 330 (4): 317. arXiv:0902.1314. Bibcode:2009AN....330..317H. doi:10.1002/asna.200811187. S2CID 17497112.
6. Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. S2CID 119323941.
7. Tetzlaff, N.; et al. (January 2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873.
8. "V* V4199 Sgr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 12 August 2013.
9. Otero, Sebastian (10 February 2012). "V4199 Sgr". The International Variable Star Index. Retrieved 14 July 2014.
10. Waelkens, C. (June 1991). "Slowly pulsating B stars". Astronomy and Astrophysics. 246: 453. Bibcode:1991A&A...246..453W.
11. Waelkens, C.; Rufener, F. (November 1985). "Photometric variability of mid-B stars". Astronomy and Astrophysics. 152: 6–14. Bibcode:1985A&A...152....6W.
12. De Cat, P.; et al. (March 2005). "A study of bright southern slowly pulsating B stars. III. Mode identification for singly-periodic targets in spectroscopy". Astronomy and Astrophysics. 432 (3): 1013–1024. Bibcode:2005A&A...432.1013D. doi:10.1051/0004-6361:20042103. hdl:2066/33307.
13. Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.