Groombridge 1830 ( Eng. Groombridge 1830 ) is a star located in the constellation Ursa Major at a distance of about 30 light-years from us.
| Grumbridge 1830 | |||
|---|---|---|---|
| Star | |||
| Research history | |||
| Discoverer | S. Grumbridge | ||
| opening date | 1838 | ||
| Observational data ( Age J2000.0) | |||
| Type of | Single star | ||
| Right ascension | |||
| Declination | |||
| Distance | 29.7 ± 0.2 St. of the year | ||
| Visible magnitude ( V ) | 6.42 | ||
| Constellation | Big Dipper | ||
| Astrometry | |||
| Radial velocity ( R v ) | -98.0 km / s | ||
| Own movement (μ) | RA: 4003.69 mas per year Dec: -5814.64 mas per year | ||
| Parallax (π) | 109.22 mas | ||
| Absolute magnitude (V) | 6.62 | ||
| Specifications | |||
| Spectral class | sdG8p VI | ||
| Color Index ( B - V ) | 0.75 | ||
| Color Index ( U - B ) | 0.17 | ||
| Variability | |||
| physical characteristics | |||
| Weight | 0,6 M ☉ | ||
| Radius | 0.64 R ☉ | ||
| Age | 5,4⋅10 9 years | ||
| Temperature | 5030 K | ||
| Metallicity | 3-10% | ||
| |||
| Database Information | |||
| SIMBAD | data | ||
| Sources: [1] | |||
Content
Study History
The star was first registered in the catalog of the British astronomer Stephen Grumbridge , published in 1838 , so she bears his name. In 1842, Friedrich Argelander calculated the star’s own motion: it turned out to be extremely large. Faster than it in our Galaxy, only the Barnard star and the Kaptein star move. The speed of Gumbridge 1830 is about 300 km / s. In the second half of the 19th century, the Portuguese observatory, the Lisbon Astronomical Observatory, was created to study this star.
Features
Unusually dim for its class , the star is a yellow-orange sub - dwarf with a mass equal to 0.6 of the mass of the Sun. [2] Having a diameter of 64% of the sun, the luminosity of a star does not exceed 19% of our star. The total mass of elements heavier than hydrogen , which are part of the Grumbridge 1830 , is approximately equal to 10% of the similar mass of the Sun. [3] Based on the data of chromospheric analysis [4] , researchers estimate the age of the star at 5.4 billion years. But these data are not consistent with the fact that Grumbridge 1830 belongs to an extensive group of halo stars, and their age is at least 10 billion years.
Flash
In 1968, American astronomer Peter van de Camp announced the discovery of a second, dimmer companion in the system, based on the increase in brightness of a star that he noticed during observations at the Sproule Observatory . However, despite periodic repeats of flares, further studies of the radial velocity [5] and spectrum [6] of the star did not confirm the presence of a massive companion in the system. Further observations showed [7] that the reason for such an increase in the brightness of Grumbridge 1830 is the unusual powerful flares characteristic of the category of “exotic” stars of the F8 – G8 classes, similar in their characteristics to the Sun, but with extremely strong chromospheric activity.
According to one theory, unusually intense flares in stars can be due to the interaction of the magnetic field of a giant planet orbiting in a narrow orbit with the magnetic field of a given star. [8] Some stars, similar to the Sun, belonging to the F8 – G8 classes, have registered tremendous power explosions (coronal stellar mass ejections), exceeding in strength 10-100 million times the most powerful flash on the Sun. These flares increased the brightness of the star up to 20 times, and the duration of this event varied from an hour to a week. Fortunately, this is not characteristic of our daylight, and so far no traces of such an event that could have happened in the past have been revealed.
Nearest star environment
The following star systems are within 10 light-years of Grumbridge 1830 :
| Star | Spectral class | Distance, st. years old |
| BD + 36 2219 | M1 Ve /? | 2,3 |
| 61 Ursa Major | G8 ve | 2.6 |
| β Hounds Dogs | G0 v | 5,0 |
| Alula South | G0 Ve / G0 Ve | 5,4 |
| G 122-49 | MV | 6.2 |
| Ross 1003 | M3.5-5 V | 6.9 |
| Gliese 436 | M2.2-3.5 V | 7.1 |
| Gliese 1138 | MV | 7.4 |
| Gliese 1134 | MV | 9.1 |
| β Hair Veronica | F9.5-G0 V | 10.0 |
Notes
- ↑ SIMBAD . - Grumbridge 1830 in the SIMBAD database . Date of treatment February 22, 2012.
- ↑ Smith, G., Lambert, DL, & Ruck, MJ A fine analysis of calcium and iron lines in the spectrum of the subdwarf Groombridge 1830 . Astronomy and Astrophysics (ISSN 0004-6361), vol. 263, no. 1-2, p. 249-257. (1992). Date of treatment April 13, 2009. Archived March 29, 2012.
- ↑ Cayrel de Strobel, G., Hauck, B., Francois, P., Thevenin, F., Friel, E., Mermilliod, M. A catalog of Fe / H determinations - 1991 edition . Astronomy and Astrophysics Supplement Series (ISSN 0365-0138), vol. 95, no. 2, p. 273-336. (09/1995). Date of treatment April 13, 2009. Archived March 29, 2012.
- ↑ Barry, DC The chromospheric age dependence of the birthrate, composition, motions, and rotation of late F and G dwarfs within 25 parsecs of the sun . Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 334, Nov. 1, 1988, p. 436-448. (11/1988). Date of treatment April 13, 2009. Archived March 25, 2012.
- ↑ Griffin, RF The radial velocity of HR 4550 (Groombridge 1830) in 1974-1984 . The Observatory, vol. 104, p. 192-193 (1984). Date of treatment April 13, 2009. Archived March 29, 2012.
- ↑ Heintz, WD Astrometric study of the subdwarf HR 4550 . Astronomical Society of the Pacific, Publications (ISSN 0004-6280), vol. 96, July 1984, p. 557, 558. (1984). Date of treatment April 13, 2009. Archived March 29, 2012.
- ↑ Schaefer, Bradley E .; King, Jeremy R .; Deliyannis, Constantine P. Superflares on Ordinary Solar-Type Stars . The Astrophysical Journal, Volume 529, Issue 2, pp. 1026-1030. (02/2000). Date of treatment April 13, 2009. Archived March 29, 2012.
- ↑ Rubenstein, Eric P .; Schaefer, Bradley E. Are Superflares on Solar Analogues Caused by Extrasolar Planets? (eng.) . The Astrophysical Journal, Volume 529, Issue 2, pp. 1031-1033. (02/2000). Date of treatment April 13, 2009. Archived March 29, 2012.
See also
- The list of stars of the constellation Ursa Major