Beta Carinae
Template:Location mark Location of β Carinae (circled) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Carina |
| Pronunciation | Template:IPAc-en[1] |
| Right ascension | Template:RA[2] |
| Declination | Template:DEC[2] |
| Apparent magnitude (V) | 1.69[3] |
| Characteristics | |
| Spectral type | A1III[4] |
| U−B Template:Engvar | +0.03[5] |
| B−V Template:Engvar | +0.00[5] |
| Astrometry | |
| Radial velocity (Rv) | −5.2[6] km/s |
| Proper motion (μ) | RA: −156.47[2] mas/yr Dec.: +108.95[2] mas/yr |
| Parallax (π) | 28.82±0.11 mas[2] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | −1.03[7] |
| Details | |
| Mass | 3.88[8] Template:Solar mass |
| Radius | 5.82[9] Template:Solar radius |
| Luminosity | 223[9] Template:Solar luminosity |
| Surface gravity (log g) | 3.50[10] cgs |
| Temperature | Script error: No such module "val".[10] K |
| Metallicity [Fe/H] | −0.36[4] dex |
| Rotational velocity (v sin i) | 145.7±2.2[11] km/s |
| Age | 260[12][8] Myr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist[13] | |
| Database references | |
| SIMBAD | data |
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Beta Carinae is the second-brightest star in the southern constellation of Carina. It has the official name Miaplacidus;[14] Beta Carinae is the star's Bayer designation, which is Latinised from β Carinae and abbreviated Beta Car or β Car. With apparent magnitude of 1.69,[3] it is one of the brightest stars in the night sky. It is the brightest star in the southern asterism known as the Diamond Cross, marking the southwestern end of the asterism. It lies near the planetary nebula IC 2448. Parallax measurements place it at a distance of Script error: No such module "convert". from the Sun.[2]
Nomenclature
β Carinae (Latinised to Beta Carinae) is the star's Bayer designation.
The star's historical name Miaplacidus made its debut on star maps in 1856 when the star atlas Geography of the Heavens, composed by Elijah Hinsdale Burritt, was published. The meaning and linguistic origin of the name remained an enigma for many decades, until William Higgins, a great scholar and expert on star names, surmised that the name Miaplacidus is apparently a bilingual combination of Arabic مياه miyāh for 'waters' and Latin placidus for 'placid'.Script error: No such module "Unsubst". The IAU Working Group on Star Names first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Miaplacidus for this star.[15]
In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Southern Boat, refers to an asterism consisting of β Carinae, V337 Carinae, PP Carinae, θ Carinae and ω Carinae.[16] Consequently, β Carinae itself is known as Script error: No such module "Lang". (Script error: No such module "Lang"., Template:Langx).[17]
Physical properties
The stellar classification of A1 III[4] mean that Miaplacidus is an evolved giant star that has exhausted the hydrogen at its core and has expanded. It has an estimated age of 260 million years.[12] This star does not show an excess emission of infrared radiation that might otherwise suggest the presence of a debris disk.[12] It has about 3.8[8] times the Sun's mass and has expanded to almost six times the radius of the Sun. Presently it is radiating 223 times as much luminosity as the Sun[9] from its outer envelope at an effective temperature of Script error: No such module "val"..[10] Despite its enlarged girth, this star still shows a rapid rotation rate, with a projected rotational velocity of 146 km/s.[11]
References
- ↑ Script error: No such module "citation/CS1".
- ↑ a b c d e f Script error: No such module "citation/CS1". Note: see VizieR catalogue I/311.
- ↑ a b Script error: No such module "Citation/CS1".
- ↑ a b c Script error: No such module "citation/CS1".
- ↑ a b Script error: No such module "citation/CS1".
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- ↑ a b c Script error: No such module "citation/CS1".
- ↑ a b c Script error: No such module "citation/CS1".
- ↑ a b c Script error: No such module "citation/CS1".
- ↑ a b Script error: No such module "citation/CS1".
- ↑ a b c Script error: No such module "citation/CS1".
- ↑ Template:Cite simbad
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Template:In lang 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, Template:ISBN.
- ↑ Template:In lang 香港太空館 - 研究資源 - 亮星中英對照表 Template:Webarchive, Hong Kong Space Museum. Accessed on line November 23, 2010.