Pi Hydrae is a type of giant known as a
cyanogen-weak star, which means that its spectrum displays weak
absorption lines of CN− relative to the
metallicity. (The last is a term astronomers use when describing the abundance of elements other than hydrogen and helium.) Otherwise, it appears to be a normal star of its evolutionary class, having undergone first
dredge-up of
nuclear fusion by-products onto its surface layers.[10] The measured
angular diameter of this star, after correction for
limb darkening, is 3.76 ± 0.04
mas.[13] At its estimated distance, this yields a physical size of about 12–13 times the
radius of the Sun.[8] It has an estimated mass of 2.45 times the
mass of the Sun.[7]
^
abcWielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb, 35 (35), Astronomisches Rechen-Institut Heidelberg: 1,
Bibcode:
1999VeARI..35....1W
^Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245,
Bibcode:
1989ApJS...71..245K,
doi:
10.1086/191373.
^
abEdvardsson, B. (January 1988), "Spectroscopic surface gravities and chemical compositions for 8 nearby single sub-giants", Astronomy and Astrophysics, 190 (1–2): 148–166,
Bibcode:
1988A&A...190..148E
^"49 Hya -- Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2012-01-16
^"The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from
the original on March 18, 2012, retrieved 2012-01-16
^Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777,
Bibcode:
2005A&A...431..773R,
doi:10.1051/0004-6361:20042039
External links
Kaler, James B.,
"PI HYA (Pi Hydrae)", Stars, University of Illinois, retrieved 2012-01-16