PZ Telescopii
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Telescopium |
| Right ascension | 18h 53m 05.87527s [1] |
| Declination | −50° 10′ 49.8802″ [1] |
| Spectral type | K0Vp[2] |
| Other designations | |
PZ Telescopii, also known as HD 174429 or simply PZ Tel, is a young star in the constellation Telescopium. It has a maximum magnitude of 8.342 (too faint to be seen with the unaided eye), varying by 0.0342 of a magnitude over roughly 23 hours.[2] It has been classified as a BY Draconis variable, and is one of the closest and hence brightest pre-main-sequence stars to Earth.[3]
Based upon an annual parallax shift of 19.42±0.98 milliarcseconds as measured by the Hipparcos satellite,[4] this system is 167.9 light-years (51.49 parsecs) from Earth, with a margin of error of 8.5 light-years (2.6 parsecs).[3]
PZ Telescopii has an effective surface temperature of around 5338 K (the Sun has an approximate surface temperature of 5778 K), a mass around 1.13 times, and diameter 1.23 times that of the Sun.[3] It has a debris disk calculated to span from a radius of 35 to 165 astronomical units (AU), as well as a substellar companion with 36 times the mass of Jupiter orbiting at a distance of 16 AU, discovered in 2008. The companion, currently known as PZ Tel B, is thought to be a brown dwarf; however it is possible (though very unlikely) that it is an extremely large Jupiter-like planet, in which case it would be PZ Tel b, and the first such planet to be directly imaged.[3]
PZ Telescopii was originally considered to be a member of the Beta Pictoris moving group; however in a 2012 paper, James Jenkins of Universidad de Chile and colleagues used three methods to calculate its age and came up with a figure of around 24 million years—significantly older than the 12 million years of the association.[3]
References
- 1 2 3 "V* PZ Telescopii -- Variable of BY Dra type". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 1 July 2014.
- 1 2 Watson, Christopher (19 April 2012). "PZ Telescopii". AAVSO Website. American Association of Variable Star Observers. Retrieved 1 July 2014.
- 1 2 3 4 5 Jenkins, J. S.; Pavlenko, Y. V.; Ivanyuk, O.; Gallardo, J.; et al. (2012). "Benchmark Cool Companions: Ages and Abundances for the PZ Telescopii System". Monthly Notices of the Royal Astronomical Society. 420 (4): 3587–98. arXiv:1111.7001
. Bibcode:2012MNRAS.420.3587J. doi:10.1111/j.1365-2966.2011.20280.x. - ↑ 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.