To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
Languages
Recent
Show all languages
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

From Wikipedia, the free encyclopedia

GRW +70 8247
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Draco
Right ascension 19h 00m 10.2534s[1]
Declination +70° 39′ 51.418″[1]
Apparent magnitude (V) 13.19[2]
Characteristics
Spectral type DAP4.5[3]
U−B color index -0.85[4]
B−V color index +0.05[4]
Astrometry
Proper motion (μ) RA: +85.774[1] mas/yr
Dec.: +505.050[1] mas/yr
Parallax (π)77.6525 ± 0.0317 mas[1]
Distance42.00 ± 0.02 ly
(12.878 ± 0.005 pc)
Details[5]
Mass1.029 M
Radius5,960[a] km
Luminosity0.013182 L
Surface gravity (log g)8.67 cgs
Temperature12540±143 K
Age(as white dwarf) 1.138 Gyr
Other designations
GJ 742, AC +70 8247, G 260-15, LFT 1446, LHS 3424, LTT 15585, Grw+70 8247, WD 1900+705[2][6]
Database references
SIMBADdata
ARICNSdata

GRW +70 8247 is a white dwarf star located 42 light-years from Earth[1] in the 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] This makes it the fifth or sixth white dwarf discovered.[b] At first, its spectrum was thought to be almost featureless,[7] but later observation showed it to have unusual broad, shallow absorption bands.[11][12] In 1970, when light that it emitted was observed to be circularly polarized, it became the first white dwarf known to have a magnetic field.[13][14] In the 1980s, it was realized that the unusual absorption bands could be explained as hydrogen absorption lines shifted by the Zeeman effect.[6][15][16]

Notes

  1. ^ Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
    .
  2. ^ The star EGGR 37 was suspected to be a white dwarf by April 1934,[8] but this was not confirmed until 1938.[9][10]

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 "LAWD 73". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved November 5, 2007.
  3. ^ 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.
  4. ^ 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.
  5. ^ "GJ 742". Montreal White Dwarf Database. Retrieved 2024-05-30.
  6. ^ 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)
  7. ^ 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.
  8. ^ 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.
  9. ^ 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.
  10. ^ 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.
  11. ^ 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.
  12. ^ 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.
  13. ^ 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)
  14. ^ 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.
  15. ^ 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)
  16. ^ 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.



This page was last edited on 30 May 2024, at 22:17
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.