Iota Carinae
Template:Short description Script error: No such module "For".
Template:Location mark Location of ι Carinae (circled in red) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Carina |
| Right ascension | Template:RA[1] |
| Declination | Template:DEC[1] |
| Apparent magnitude (V) | 2.21[2] |
| Characteristics | |
| Spectral type | A7 Ib[3] |
| U−B Template:Engvar | +0.16[4] |
| B−V Template:Engvar | +0.18[4] |
| Variable type | Suspected[5] |
| Astrometry | |
| Radial velocity (Rv) | 13.3[2] km/s |
| Proper motion (μ) | RA: −19.03 mas/yr[1] Dec.: +13.11 mas/yr[1] |
| Parallax (π) | 4.26±0.1 mas[1] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | −5.1[6] |
| Details | |
| Mass | 6.9[7] Template:Solar mass |
| Radius | 46.4–50.1[7] Template:Solar radius |
| Luminosity | 4,900[8] Template:Solar luminosity |
| Surface gravity (log g) | Script error: No such module "val".[7] cgs |
| Temperature | 7,500[7]–7,700[9] K |
| Metallicity [Fe/H] | −0.14[8] dex |
| Rotational velocity (v sin i) | 10.0[8] km/s |
| Age | 56[7] Myr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist[10] | |
| Database references | |
| SIMBAD | data |
Script error: No such module "Check for unknown parameters".
Iota Carinae is a star in the southern constellation of Carina. It has the official name Aspidiske, pronounced Template:IPAc-en;[11] Iota Carinae is its Bayer designation, which is Latinized from ι Carinae and abbreviated Iota Car or ι Car. With an apparent visual magnitude of 2.2,[2] it is one of the brighter stars in the night sky.
Appearance and location
The star and rest of southern Carina never sets on places from about 34° S southwards including Cape Town; its northernmost viewpoints are unobstructed southern horizons near to the 30th parallel north, once a day.[12]
The False Cross is an asterism formed from Iota Carinae, Delta Velorum, Kappa Velorum and Epsilon Carinae. It is so called because it is sometimes mistaken for the Southern Cross, causing errors in astronavigation.[13]
The star appears 46.0' (0.7668°) WSW of V357 Carinae, a mid-third-magnitude star, also forming part of the asterism and leading to its long, narrow projection which culminates in Canopus.[14]
Nomenclature
ι Carinae (Latinised to Iota Carinae) is the star's Bayer designation.
It has the traditional cognate names Aspidiske (not be confused with Asmidiske, the proper name of Xi Puppis), Scutulum and Turais (or Tureis, a name shared with Rho Puppis). Turais is the Arabic تُرَيْس turais "small shield" (diminutive), while Aspidiske and Scutulum are Greek and Latin translations from ασπίδα and scūtum.[12] In 2016, the International Astronomical Union formed its Working Group on Star Names (WGSN)[15] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[16] included a table of the first two batches of names it approved which included Aspidiske for this star.
In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Sea Rock, refers to an asterism consisting of Iota Carinae, Epsilon Carinae, HD 83183, HD 84810 and Upsilon Carinae.[17] Consequently, Iota Carinae itself is known as Script error: No such module "Lang". (Script error: No such module "Lang"., Template:Langx).[18]
Properties
Based on parallax measurements this star is about Script error: No such module "convert". from the Earth. It has a stellar classification of A7 Ib,[3] with the luminosity class of 'Ib' indicating it has reached the stage of its evolution where it has expanded to become a lower-luminosity supergiant. It is just entering the Hertzsprung gap of the Hertzsprung–Russell diagram, and is evolving towards a red supergiant phase.[19]
Iota Carinae has around seven times the Sun's mass and has expanded to roughly 50 times the Sun's radius.[7] It is radiating about 4,900 times the luminosity of the Sun.[8] However, this luminosity appears to vary, causing the star's apparent magnitude to range between 2.23 and 2.28.[5] This energy is being radiated into space from the star's outer envelope at an effective temperature of 7,500 K,[7] giving Iota Carinae the white hue typical of an A-type star.[20] Being short of the rough initial mass limit above which stars collapse and explode as supernovae, Iota Carinae will likely end its life as a white dwarf with roughly the current mass of the Sun, similar to Sirius B today[21] (which was also estimated to have an initial mass of up to 7 solar masses).[22]
Due to precession of the Earth's axis of rotation, in the next 7,500 years the south celestial pole will pass close to this star and Upsilon Carinae and it will become the South Star around 8100 CE.[23]
References
<templatestyles src="Reflist/styles.css" />
- ↑ a b c d 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 Script error: No such module "Citation/CS1".
- ↑ a b Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ a b c d e f g Script error: No such module "Citation/CS1".
- ↑ a b c d Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ a b Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ In the Sky Map, Dominic Ford, 2011–2019.
- ↑ 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.
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
Script error: No such module "Check for unknown parameters".
Template:Stars of Carina Template:Portal bar Template:Authority control