Star in the constellation Draco
GRW +70 8247 is a white dwarf star located 42 light-years from Earth [ 1] constellation Draco . With a magnitude of about 13 it is visible only through a large telescope .
Properties
Although photographed in the 19th century as part of the Carte du Ciel project, the star was not determined to be a white dwarf until G. P. Kuiper observed it in 1934.[ 7] [ b] spectrum was thought to be almost featureless,[ 7] absorption bands .[ 11] [ 12] circularly polarized , it became the first white dwarf known to have a magnetic field .[ 13] [ 14] hydrogen absorption lines shifted by the Zeeman effect .[ 6] [ 15] [ 16]
Notes
^ Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K :
(
5
,
772
11
,
880
)
4
⋅
10
−
2.88
=
0.00857
R
⊙
{\displaystyle {\sqrt {{\biggl (}{\frac {5,772}{11,880}}{\biggr )}^{4}\cdot 10^{-2.88}}}=0.00857\ R_{\odot }}
^ The star EGGR 37 was suspected to be a white dwarf by April 1934,[ 8] [ 9] [ 10]
References
^ 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 .^ a b "LAWD 73" . SIMBAD Centre de données astronomiques de Strasbourg . Retrieved November 5, 2007 .^ Wesemael, F.; Greenstein, J. L.; Liebert, James; Lamontagne, R.; Fontaine, G.; Bergeron, P.; Glaspey, J. W. (1993). "An atlas of optical spectra of white-dwarf stars" . Publications of the Astronomical Society of the Pacific . 105 : 761. Bibcode :1993PASP..105..761W . doi :10.1086/133228 S2CID 122605705 . ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)" . Catalogue of Eggen's UBV Data . Bibcode :1986EgUBV........0M . ^ "GJ 742" . Montreal White Dwarf Database . Retrieved 2024-05-30 .^ a b Jesse L. Greenstein, Ronald J. W. Henry, and R. F. O'Connell (February 15, 1985). "Further identifications of hydrogen in Grw +70°8247" . Astrophysical Journal . 289 : L25 – L29 . Bibcode :1985ApJ...289L..25G . doi :10.1086/184427 {{cite journal }}: CS1 maint: multiple names: authors list (link )^ a b G. P. Kuiper (October 1934). "Two New White Dwarfs of Large Parallax" . Publications of the Astronomical Society of the Pacific . 46 (273): 287– 290. Bibcode :1934PASP...46..287K . doi :10.1086/124496 . S2CID 123421818 . ^ P. J. van Rhijn and J. J. Raimond (April 1934). "Some new members of the Hyades cluster" . Monthly Notices of the Royal Astronomical Society 94 (6): 508– 518, at p. 517. Bibcode :1934MNRAS..94..508V . doi :10.1093/mnras/94.6.508 ^ Jöran M. Ramberg (May 1938). "Zwei weiße Zwerge unter den physischen Hyadenmigliedern" . Astronomische Nachrichten (in German). 265 (6– 7): 111– 112. Bibcode :1938AN....265..111R . doi :10.1002/asna.19382650609 . ^ See also Gerard P. Kuiper (August 1941). "List of Known White Dwarfs" . Publications of the Astronomical Society of the Pacific . 53 (314): 248– 252. Bibcode :1941PASP...53..248K . doi :10.1086/125335 S2CID 123040354 .
^ Walter S. Adams and Frederick H. Seahes (1938). "Annual Report of the Director of the Mount Wilson Observatory (1937-1938)" . Mount Wilson Observatory Annual Report . 10 : 28. Bibcode :1938MWOAR..10....1A . ^ Jesse L. Greenstein and Mildred S. Matthews (July 1957). "Studies of the White Dwarfs. I. Broad Features in White Dwarf Spectra" . Astrophysical Journal . 126 : 14– 18. Bibcode :1957ApJ...126...14G . doi :10.1086/146364 . ^ James C. Kemp, John B. Swedlund, J. D. Landstreet, and J. R. P. Angel (August 1970). "Discovery of Circularly Polarized Light from a White Dwarf" . Astrophysical Journal . 161 : L77 – L79 . Bibcode :1970ApJ...161L..77K . doi :10.1086/180574 . {{cite journal }}: CS1 maint: multiple names: authors list (link )^
Angel, J.R.P.; Landstreet, J.D.; Oke, J.B. (1972). "The Spectral Dependence of Circular Polarization in Grw+70°8247" . Astrophysical Journal . 171 : L11 – L15 . Bibcode :1972ApJ...171L..11A . doi :10.1086/180857
^ J. R. P. Angel, James Liebert, and H. S. Stockman (May 1, 1985). "The optical spectrum of hydrogen at 160-350 million gauss in the white dwarf Grw +70°8247" . Astrophysical Journal . 292 : 260– 266. Bibcode :1985ApJ...292..260A . doi :10.1086/163156 . {{cite journal }}: CS1 maint: multiple names: authors list (link )^ D. T. Wickramasinghe and Lilia Ferrario (April 1, 1988). "A centered dipole model for the high field magnetic white dwarf GRW +70°8247" . Astrophysical Journal . 327 : 222– 233. Bibcode :1988ApJ...327..222W . doi :10.1086/166184
Information related to GRW +70 8247
