SDSS J142625.71 + 575218.3
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Star SDSS J142625.71 + 575218.3 |
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| AladinLite | |||
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | Big Bear | ||
| Right ascension | 14 h 26 m 25.7 s | ||
| declination | + 57 ° 52 ′ 18.3 ″ | ||
| Apparent brightness | (19.37) mag | ||
| Typing | |||
| B − V color index | (0.33) | ||
| Spectral class | DQB | ||
| Variable star type | ZZ | ||
| Astrometry | |||
| parallax | (3.08 ± 0.32) mas | ||
| distance | (1,060) ly (325) pc |
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| Proper movement | |||
| Rec. Share: | (3.61) mas / a | ||
| Dec. portion: | (11,10) mas / a | ||
| Physical Properties | |||
| Luminosity |
1/600 L ☉ |
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| Effective temperature | (19,830 ± 750) K. | ||
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Other names and catalog entries |
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SDSS J142625.71 + 575218.3 is a white dwarf star from the catalog of the Sloan Digital Sky Survey (SDSS). It is located in the constellation Great Bear .
It is the first known star of the white dwarfs of the type DQ and thus also their prototype.
Prototype features are
- The loss of the hydrogen and helium shell, so that the carbon underneath appears.
- A regular pulsation . It is assumed that the pulsations are the result of cooling, during which the ionized carbon becomes neutral again.
The pulsation rate is eight minutes and the fluctuation is two percent. Although the star is 600 times fainter than the sun , it has a surface temperature of around 19,800 K, more than three times the surface temperature. The star glows blue. In addition, the star has a measurable magnetic field of about 1.2 Mega Gauss , so 120 T .
discovery
In 2007, Patrick Dufour and James Liebert from the University of Arizona discovered a previously unknown class of white dwarfs: carbon white dwarfs . These have lost both their hydrogen and helium shells. The reasons for this are still not understood today.
Shortly afterwards, Michael H. Montgomery from the University of Texas at Austin was able to show that these stars can also pulsate. A team led by Montgomery and Kurtis A. Williams then began the systematic search for such stars.
The search was carried out with the 2.1-meter Otto Struve telescope at the McDonald Observatory at the University of Texas. It was the student Steven DeGennaro who finally discovered that SDSS J142625.71 + 575218.3 met the required characteristics.
On May 1, 2008, the discovery was announced on the news page of the McDonald Observatory.
See also
Web links
- Image of SDSS J142625.71 + 575218.3 with surroundings (text in English)
- Pulsations from SDSS J142625.71 + 575218.3 (text in English)
Individual evidence
- ↑ a b c d e SDSS J142625.71 + 575218.3. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on October 11, 2019 .
- ↑ a b c L. E. Ferrario, D. De Martino, B. Gänsicke: Magnetic White Dwarfs . In: Space Science Reviews . 191, 2015, pp. 111-160. arxiv : 1504.08072 . doi : 10.1007 / s11214-015-0152-0 .
- ↑ V0430 UMa. In: VSX. AAVSO , accessed October 11, 2019 .
- ↑ New star type: Kohlige white dwarfs. In: Image of Science. 7/2008. Konradin Medien, Leinfelden-Echterdingen. ISSN 0006-2375
- ↑ McDonald Observatory News: McDonald Observatory Astronomers Discover New Type of Pulsating White Dwarf Star. On: mcdonaldobservatory.org