Vela X-1

Vela X-1

Starbox begin
name=Vela X-1Starbox observe
epoch=J2000.0 (ICRS)
constell=Vela
ra=RA|09|02|06.860
dec=DEC|-40|33|16.91
appmag_v=6.76 to 6.99
(supergiant component)Starbox character
class=B0.5Ib
(supergiant component)
b-v=0.50
(supergiant component)
u-b=-0.51
(supergiant component)
variable="several causes"Starbox astrometry
prop_mo_ra=−5.81
prop_mo_dec=8.25
dist_ly=6200±650
dist_pc=1900±200Starbox detail
mass=1.88
radius=?
luminosity=?
temperature=?
metal=?
rotation=8.964 days
age=? Starbox catalog
names="Supergiant component:" GP Vel, HD 77581, SAO 220767, HIP 44368, CPD-40°3072, CD-40°4838; "X-ray component:" 1XRS 09002-403, 1RXS J090207.0-403311, 4U 0900-40

Vela X-1 is a high-mass X-ray binary system, associated with the Uhuru source 4U 0900-40.

Chacteristics

Vela X-1 consists of an accreting X-ray pulsar in orbit around HD 77581, a supergiant star. The orbital period of the system is 8.964 days and the neutron star is eclipsed for about two days of each orbit by HD 77581. The spin period of the neutron star is about 283 seconds. Long term monitoring of the spin period shows small random increases and decreases over time similar to a random walk. [ [http://adsabs.harvard.edu/abs/1997ApJS..113..367B Observations of Accreting Pulsars] , L. Bildsten, et al., 1997, Astrophysical Journal Supplement Series, 113, p. 367.] The X-ray emission of the neutron star is caused by the capture and accretion of matter from the stellar wind of the supergiant companion. The accreting matter causes the random spin period changes. The mass of the pulsar is estimated to be at least 1.88 solar masses. [ [http://adsabs.harvard.edu/abs/2003A&A...401..313Q The mass of the neutron star in Vela X-1 and tidally induced non-radial oscillations in GP Vel] , H. Quaintrell et al., "Astronomy and Astrophysics" 401 (April 2003), pp. 313–323; also, [http://arxiv.org/abs/astro-ph/0301243 arXiv:astro-ph/0301243] .]

Note

Vela X-1 should not be confused with the isolated radio pulsar, Vela X, which is a very different kind of object. Vela X is associated with a very strong 100 MeV gamma-ray source, and with the rather weak Uhuru X-ray source, 4U 0833-45.

References

See also

* High-mass X-ray binary
* List of X-ray pulsars
* X-ray binary

External links

* [http://f64.nsstc.nasa.gov/batse/pulsar/data/sources/velax1.html Spin frequency history of Vela X-1]


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Vela — puede referirse a: Vela de cera o de otro combustible, para la iluminación. Véase también: Candela (desambiguación) Vela o vela de barco, para aprovechar la energía del viento. Vela, deporte de la vela Vela ligera, tipo de navegación con veleros… …   Wikipedia Español

  • VELA (V.) — VELA VINCENZO (1820 1891) Sculpteur suisse d’origine italienne. Né à Ligornetto, Vela fut actif en Suisse et en Italie. Au cours d’une longue carrière, Vicenzo Vela a proposé à la sculpture italienne des préoccupations thématiques et stylistiques …   Encyclopédie Universelle

  • Vela — ist die lateinische Pluralform für Segel. Davon abgeleitet werden bezeichnet: ein Sternbild, siehe Segel des Schiffs ein Pulsar in diesem Sternbild, den Vela Pulsar oder PSR 0833 45 eine amerikanische Satellitenserie zur Überwachung überirdischer …   Deutsch Wikipedia

  • vela — / vela/ s.f. [dal lat. vela, pl. di velum vela , passato a femm. sing. nel lat. parlato]. 1. (marin.) [telo, o insieme di teli di varia forma e grandezza, applicato all alberatura di un natante per provocarne l avanzamento sfruttando l azione del …   Enciclopedia Italiana

  • Vela — may refer to: * Vela, a constellation (the Sails) * Vela Pulsar, a pulsar in the constellation of Vela * Project Vela, a system developed by the United States to monitor compliance with the Partial Test Ban Treaty ** Vela (satellite), a series of …   Wikipedia

  • velă — VÉLĂ, vele, s.f. Pânză de corabie, care asigură deplasarea navei sub acţiunea vântului; p. ext. corabie, ambarcaţie cu pânze. ♦ (La pl.) Sport care se practică cu ajutorul ambarcaţiunilor cu pânze. – Din it. vela. Trimis de RACAI, 30.09.2003.… …   Dicționar Român

  • Vela — Vela  название группы спутников, разработанных в рамках элемента Vela Hotel программы США Vela, нацеленное на слежение за соблюдением СССР договора 1963 года о частичном запрещении испытаний ядерного оружия. Название проекта на испанском… …   Википедия

  • vela — vela, estar a dos velas expr. pobre, sin dinero, sin nada. ❙ «...Lucía se quedó a dos velas, sólo a expensas del dinero que su hermano...» Javier Maqua, Invierno sin pretexto, 1992, RAECREA. ❙ «Encima no tengo vitaminas, que estoy a dos velas.»… …   Diccionario del Argot "El Sohez"

  • Vela X-I — Vela X 1 Pour les articles homonymes, voir X 1. Vela X 1 est un système binaire composé d une étoile massive et d une étoile à neutrons, formant une binaire X à forte masse. Il est situé au sein de la constellation des Voiles, dont il est la… …   Wikipédia en Français

  • Vela x-1 — Pour les articles homonymes, voir X 1. Vela X 1 est un système binaire composé d une étoile massive et d une étoile à neutrons, formant une binaire X à forte masse. Il est situé au sein de la constellation des Voiles, dont il est la source la… …   Wikipédia en Français

  • vela — |é| s. f. 1. Pano forte e resistente que se prende aos mastros para fazer andar as embarcações, ou aos braços dos moinhos de vento para os fazer girar. 2.  [Figurado] Navio; embarcação. 3. Ato de velar. 4. Privação de sono durante a noite.… …   Dicionário da Língua Portuguesa

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”