PZ Telescopii

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PZ Telescopii
Observation data
Epoch J2000      Equinox J2000
Constellation Telescopium
Right ascension 18h 53m 05.87338s[1]
Declination −50° 10′ 49.9014″[1]
Apparent magnitude (V) 8.33 - 8.63[2]
Characteristics
Spectral type G9 IV[3] + M7±1[4]
B−V color index +0.784±0.021[5]
Variable type BY Dra[2]
Astrometry
Radial velocity (Rv)−4.2±0.2[5] km/s
Proper motion (μ) RA: +16.348±0.084[1] mas/yr
Dec.: −85.254±0.084[1] mas/yr
Parallax (π)21.2186 ± 0.0602[1] mas
Distance153.7 ± 0.4 ly
(47.1 ± 0.1 pc)
Absolute magnitude (MV)4.88[5]
Orbit[4]
Period (P)622.2 yr
Semi-major axis (a)1.504″
Eccentricity (e)0.755
Inclination (i)92.05°
Longitude of the node (Ω)58.43°
Periastron epoch (T)2000.0
Argument of periastron (ω)
(secondary)		264.38°
Details[6]
Mass1.13±0.03 M☉
Radius1.23±0.04 R☉
Luminosity0.993+0.004
−0.005[1] L☉
Surface gravity (log g)4.41±0.10 cgs
Temperature5,338±200 K
Metallicity [Fe/H]+0.05±0.20 dex
Rotation0.943±0.002[4]
Rotational velocity (v sin i)69.0±0.1[3] km/s
Age24±3 Myr
B
Mass38–72[4] MJup
Surface gravity (log g)< 4.5[4] cgs
Temperature2,700±100 K
Other designations
PZ Tel, CD−50°12190, HD 174429, HIP 92680, SAO 245781, PPM 347231, WDS J18531-5011AB[7]
Database references
SIMBADdata

PZ Telescopii, also known as HD 174429 or simply PZ Tel, is a young star in the constellation Telescopium. Based on parallax measurements, it is located at a distance of 154 light years from the Sun. The star is drifting closer with a radial velocity of −4 km/s.[5] It is too faint to be visible to the naked eye and is classified as a BY Draconis variable that ranges in apparent visual magnitude from 8.33 down to 8.63 over a period of 22.581 hours (0.94088 days).[2] It is one of the closest and hence brightest pre-main-sequence stars to Earth.[6]

PZ Telescopii has an effective surface temperature of around 5,338 K (the Sun has an approximate surface temperature of 5,778 K), a mass around 1.13 times, and diameter 1.23 times that of the Sun.[6] The star has a high rate of spin, showing a projected rotational velocity of 69 km/s[3] and a rotation period of 22.6 h.[4] It is radiating about the same luminosity as the Sun. 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.[6]

This star has an orbiting 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.[6] Preliminary orbital elements give a best fit orbital period of 622.2 years with an eccentricity of 0.755.[4]

References[]

  1. ^ a b c d e f 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.
  2. ^ 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.
  3. ^ a b c Torres, C. A. O.; Quast, G. R.; Silva, L. da; Reza, R. de la; Melo, C. H. F.; Sterzik, M. (December 1, 2006). "Search for associations containing young stars (SACY) - I. Sample and searching method". Astronomy & Astrophysics. 460 (3): 695–708. arXiv:astro-ph/0609258. Bibcode:2006A&A...460..695T. doi:10.1051/0004-6361:20065602. ISSN 0004-6361. S2CID 16080025.
  4. ^ a b c d e f g Maire, A. -L.; et al. (March 2016). "First light of the VLT planet finder SPHERE. II. The physical properties and the architecture of the young systems PZ Telescopii and HD 1160 revisited". Astronomy & Astrophysics. 587: 24. arXiv:1511.04072. Bibcode:2016A&A...587A..56M. doi:10.1051/0004-6361/201526594. S2CID 44360238. A56.
  5. ^ a b c d 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.
  6. ^ a b c d e 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. S2CID 18735984.
  7. ^ "V* PZ Tel". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 1 July 2014.

External links[]

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