Nu Puppis (ν Puppis), also named Pipit,[11] is a solitary,[12] blue-hued star in the southern constellation of Puppis. It is the fifth-brightest star in Puppis, with an apparent visual magnitude of 3.17.[2] Based upon an annual parallax shift of 8.78 mas as seen from Earth,[1] it is located about 370 light years from the Sun. The system made its closest approach about 3.6 million years ago when it underwent perihelion passage at a distance of roughly 27 light years.[13]
The star has a stellar classification of B8 III,[3] matching a B-typegiant. Absorption lines in the spectrum are displaying central quasi-emission peaks, indicating this is a Beshell star with a circumstellar disk of heated gas that is being seen edge-on.[14] ν Puppis is a candidate variable star showing an amplitude of 0.0117 magnitude with a frequency of 0.15292 per day.[15] It is spinning rapidly with a projected rotational velocity of 225 km/s. This rotation is giving the star an oblate shape, with the equator being 17% larger than the poles. Similarly, the effective temperature and surface gravity vary across latitudes. The star's equatorial radius, temperature and surface gravity are estimated at 6.8 R☉, 10,000 K and 2.9 cgs, while the polar radius, temperature and surface gravity are 5.8 R☉, 13,000 K and 3.4 cgs.[7]
^ abcdCousins, A. W. J. (1973), "Revised zero points and UBV photometry of stars in the Harvard E and F regions", Memoirs of the Royal Astronomical Society, 77: 223–236, Bibcode:1973MmRAS..77..223C.
^ abHouk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
^Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G.; Valentini, M.; Torralba Elipe, G.; Steinmetz, M.; Pantaleoni-González, M.; Malhotra, S.; Jiménez-Arranz, Ó.; Enke, H.; Casamiquela, L.; Ardèvol, J. (2024), "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost", Astronomy and Astrophysics, 691: A98, arXiv:2407.06963, Bibcode:2024A&A...691A..98K, doi:10.1051/0004-6361/202451427.
^ abcdeBaade, D.; Pigulski, A.; Rivinius, Th; Wang, L.; Martayan, Ch; Handler, G.; Panoglou, D.; Carciofi, A. C.; Kuschnig, R.; Mehner, A.; Moffat, A. F. J.; Pablo, H.; Rucinski, S. M.; Wade, G. A.; Weiss, W. W. (2018-12-01), "Short-term variability and mass loss in Be stars - IV. Two groups of closely spaced, approximately equidistant frequencies in three decades of space photometry of ν Puppis (B7-8 IIIe)", Astronomy & Astrophysics, 620: A145, arXiv:1808.10254, doi:10.1051/0004-6361/201834161, ISSN0004-6361.
^Rivinius, Th.; et al. (August 1999), "Central quasi-emission peaks in shell spectra and the rotation of disks of Be stars", Astronomy and Astrophysics, 348: 831–842, Bibcode:1999A&A...348..831R.