TY Pyxidis

TY Pyxidis is an eclipsing binary star in the constellation Pyxis. The apparent magnitude ranges from 6.85 to 7.5 over 3.2 days.^[3]

TY Pyxidis

A light curve for TY Pyxidis, plotted from TESS data[1]
Observation data Epoch J2000      Equinox J2000
Constellation	Pyxis
Right ascension	08h 59m 42.72169s[2]
Declination	–27° 48′ 58.6885″[2]
Apparent magnitude (V)	6.85 - 7.5[3]
Characteristics
Spectral type	G5IV + G5IV
Variable type	RS Canum Venaticorum variable
Astrometry
Radial velocity (Rv)	+63.20 ± 1 km/s
Proper motion (μ)	RA: –44.46 ± 0.34[2] mas/yr Dec.: –44.36 ± 0.42[2] mas/yr
Parallax (π)	17.73±0.52 mas[2]
Distance	184 ± 5 ly (56 ± 2 pc)
Details
Radius	2.2[4] R☉
Temperature	5400[4] K
Other designations
TY Pyxidis, CD−27° 6141, HD 77137, HIP 44164, SAO 176805.
Database references
SIMBAD	data

The two components are both of spectral type G5IV,^[4] have a mass of 1.2 solar masses and revolve around each other every 3.2 days.^[5] Each star is around 2.2 times the diameter of the Sun.^[4]

The system is classified as either a RS Canum Venaticorum variable^[3] or a BY Draconis variable, stars that vary on account of prominent starspot activity,^[4] and lies 184 ± 5 light years away.^[2] The system emits X-rays, and analysing the emission curve over time led Pres and colleagues to conclude that there was a loop of material arcing between the two stars.^[6]

References

1. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
2. van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600
3. Watson, Christopher (4 January 2010). "TY Pyxidis". The International Variable Star Index. American Association of Variable Star Observers. Retrieved 30 July 2015.
4. Strassmeier, Klaus G. (2009). "Starspots". The Astronomy and Astrophysics Review. 17 (3): 251–308. Bibcode:2009A&ARv..17..251S. doi:10.1007/s00159-009-0020-6.
5. Andersen, J.; Popper, D. M. (1975). "The G-type eclipsing binary TY Pyxidis". Astronomy and Astrophysics. 39: 131–34. Bibcode:1975A&A....39..131A.
6. Pres, Pawel; Siarkowski, Marek; Sylwester, Janusz (1995). "Soft X-ray imaging of the TY Pyx binary system - II. Modelling the interconnecting loop-like structure". Monthly Notices of the Royal Astronomical Society. 275 (1): 43–55. Bibcode:1995MNRAS.275...43P. doi:10.1093/mnras/275.1.43.