Article · Wikipedia archive · Last revised Jun 15, 2026

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.

Last revised
Jun 15, 2026
Read time
≈ 1 min
Length
338 w
Citations
17
Source
TY Pyxidis

A light curve for TY Pyxidis, plotted from TESS data1
Observation data
Epoch J2000      Equinox J2000
Constellation Pyxis
Right ascension 08h 59m 42.72169s2
Declination –27° 48′ 58.6885″2
Apparent magnitude (V) 6.85 - 7.53
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 ± 0.342 mas/yr
Dec.: –44.36 ± 0.422 mas/yr
Parallax (π)17.73±0.52 mas2
Distance184 ± 5 ly
(56 ± 2 pc)
Details
Radius2.24 R
Temperature54004 K
Other designations
TY Pyxidis, CD−27° 6141, HD 77137, HIP 44164, SAO 176805.
Database references
SIMBADdata

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

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 variable3 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

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.