U Antliae

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U Antliae
Antlia constellation map.svg
Red circle.svg
Location of U Antliae (circled)
Observation data
Epoch J2000       Equinox J2000
Constellation Antlia
Right ascension 10h 35m 12.852s [1]
Declination −39° 33 45.32 [1]
Apparent magnitude  (V)5.27 - 6.04 [2]
Characteristics
Evolutionary stage AGB
Spectral type C-N3 [3] (C5,3 [4] )
U−B color index 7.10 [5]
B−V color index 2.84 [5]
Variable type LB [6]
Astrometry
Radial velocity (Rv)41.00 [7]  km/s
Proper motion (μ)RA: −31.372±0.228 [8]   mas/yr
Dec.: 2.371±0.267 [8]   mas/yr
Parallax (π)3.5717 ± 0.2043  mas [8]
Distance 910 ± 50  ly
(280 ± 20  pc)
Absolute magnitude  (MV)−1.87 [9]
Details
Radius 325 [10]   R
Luminosity 8,000 [11]   L
Temperature 2,800 [11]   K
Other designations
HR  4153, HD  91793, HIP  51821, CD−38°6579, 2MASS  J10351285-3933453, PPM  287864, AAVSO  1030–39, SAO  201533
Database references
SIMBAD data

ALMA image of the dust shells around U Antliae U Antliae - ALMA - Eso1730a.tif
ALMA image of the dust shells around U Antliae

U Antliae (U Ant) is a variable star in the constellation Antlia. It is a carbon star surrounded by two thin shells of dust.

U Antliae is an extremely red C-type carbon star. These cool stars on the asymptotic giant branch are further reddened by strong mass loss and dust that forms around the star. U Antliae is calculated to have an effective surface temperature of 2,800  K , although the light that reaches us has an appearance more like that from a black body with a temperature of 2,300 K surrounded by dust at a temperature of 72 K. [11] It emits most of its radiation in the infrared and although it is only about 500 times brighter than the sun at visual wavelengths, [9] its bolometric luminosity is 8,000 times higher than the Sun's. [11]

The visual band light curve of T Antliae, from AAVSO data UAntLightCurve.png
The visual band light curve of T Antliae, from AAVSO data

U Antliae is an irregular variable star with an apparent magnitude that varies between 5.27 and 6.04. Approximately 900 light years from Earth, it is surrounded by two shells of dust, thought to have been ejected 14,000 and 10,000 years ago. [13] The exact origin and structure of the shells is uncertain, possibly due to enhanced mass loss during thermal pulses, possibly due to interaction of the stellar wind with interstellar material. [11]

Related Research Articles

Antlia Constellation in the Southern Celestial Hemisphere

Antlia is a constellation in the Southern Celestial Hemisphere. Its name means "pump" in Latin and Greek; it represents an air pump. Originally Antlia Pneumatica, the constellation was established by Nicolas-Louis de Lacaille in the 18th century. Its non-specific (single-word) name, already in limited use, was preferred by John Herschel then welcomed by the astronomic community which officially accepted this. North of stars forming some of the sails of the ship Argo Navis, Antlia is completely visible from latitudes south of 49 degrees north.

R Hydrae Variable star in the constellation Hydra

R Hydrae, abbreviated R Hya, is a single star in the equatorial constellation of Hydra, about 2.7° to the east of Gamma Hydrae. It is a Mira-type variable that ranges in apparent visual magnitude from 3.5 down to 10.9 over a period of 389 days. At maximum brightness the star can be seen with the naked eye, while at minimum a telescope of at least 5 cm is needed. This star is located at a distance of approximately 410 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −10 km/s.

R Cassiopeiae Star in the constellation Cassiopeia

R Cassiopeiae is a variable star in the northern constellation of Cassiopeia. It is located approximately 574 light years distant from the Sun, but is drifting closer with a radial velocity of −23 km/s. This is a pulsating Mira-type variable star with a brightness varies from magnitude +4.4 down to +13.5 with a period of 433.6 days. At its maximum, R Cassiopeiae is visible to the naked eye as a faint, red-hued star.

R Centauri Variable star in the constellation Centaurus

R Centauri is a Mira variable star in the constellation Centaurus.

V Aquilae Carbon star in the constellation Aquila

V Aquilae is a carbon star and semiregular variable star in the constellation Aquila. It has an apparent magnitude which varies between 6.6 and 8.4 and is located around 400 parsecs (1,300 ly) away.

T Cephei Star in the constellation Cepheus

T Cephei is a Mira variable star in the constellation Cepheus. Located approximately 570 ± 40 light-years distant, it varies between magnitudes 5.2 and 11.3 over a period of around 388 days.

HD 97048 or CU Chamaeleontis is a Herbig Ae/Be star 603 ly away in the constellation Chamaeleon. It is a variable star embedded in a dust cloud containing a stellar nursery, and is itself surrounded by a dust disk.

R Boötis Star in the constellation Boötes

R Boötis is a variable star in the northern constellation of Boötes. Typically the star is too faint to be readily visible to the naked eye, with a brightness that fluctuates between apparent visual magnitudes of 9.98. The distance to this star is approximately 2,150 light years based on parallax measurements. It is drifting closer with a radial velocity of about −58 km/s.

W Andromedae Variable star in the constellation Andromeda

W Andromedae is a variable star in the constellation of Andromeda. It is classified as a Mira variable and S-type star, and varies from an apparent visual magnitude of 14.6 at minimum brightness to a magnitude of 6.7 at maximum brightness, with a period of approximately 397.3 days. The star is losing mass due to stellar winds at a rate of 2.79×10−7M/yr.

U Camelopardalis Star in the constellation Camelopardalis

U Camelopardalis is a semiregular variable star in the constellation Camelopardalis. Based on parallax measurements made by the Hipparcos spacecraft, it is located about 3,000 light-years away from the Earth. Its apparent visual magnitude is about 8, which is dim enough that it cannot be seen with the unaided eye.

U Hydrae Variable star in the constellation Hydra

U Hydrae is a single star in the equatorial constellation of Hydra, near the northern constellation border with Sextans. It is a semiregular variable star of sub-type SRb, with its brightness ranging from visual magnitude (V) 4.7 to 5.2 over a 450-day period, with some irregularity. This object is located at a distance of approximately 680 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −26 km/s.

AH Scorpii Red supergiant variable star in the constellation Scorpius

AH Scorpii is a red supergiant variable star located in the constellation Scorpius. It is one of the largest stars known by radius and is also one of the most luminous red supergiant stars in the Milky Way.

TT Cygni Star in the constellation Cygnus

TT Cygni is a carbon star located 561 parsecs (1,830 ly) away in the northern constellation of Cygnus. It is classified as a semiregular variable of subtype SRb that ranges in brightness from magnitude 7.26 down to 8.0 with a period of 118 days. This object is called a carbon star because it has a high ratio of carbon to oxygen in its surface layers. The carbon was produced by helium fusion, dredged up from inside the star by deep convection triggered by a flash from the helium shell.

RS Telescopii Star in the constellation Telescopium

RS Telescopii, abbreviated RS Tel, is a variable star in the southern constellation of Telescopium. It is a dim star with an apparent visual magnitude of 10.67, which is much too faint to be visible without a telescope. The variability of this star was discovered by Evelyn F. Leland and announced by Edward C. Pickering in 1910. It was first studied by Cecilia H. Payne in 1928 at the Harvard College Observatory.

V Antliae Variable star in the constellation Antlia

V Antliae is a Mira variable star in the constellation Antlia. It varies in brightness between magnitudes 8.2 and 14.0 with a period of 303 days.

S Cassiopeiae Star in the constellation Cassiopeia

S Cassiopeiae is a Mira variable and S-type star in the constellation Cassiopeia. It is an unusually cool star, rapidly losing mass and surrounded by dense gas and dust producing masers.

T Leporis Variable star in the constellation Lepus

T Leporis is a variable star in the constellation of Lepus, the Hare. It is located half a degree from ε Leporis in the sky; its distance is approximately 1,100 light years from the Solar System. It has the spectral type M6ev, and is a Mira variable — as is R Leporis, in the same constellation — whose apparent magnitude varies between +7.40 and +14.30 with a period of 368.13 days.

V Crucis Variable star in the constellation Crux

V Crucis is a carbon star in the constellation Crux. A Mira variable, its apparent magnitude ranges from 8.7 to 11.1 over 376.5 days. The fact that this star's period is nearly equal to one year makes it hard to get good observational coverage over the entire cycle. Its near-infrared light curve shows a contribution from the first harmonic of the fundamental period.

ST Camelopardalis Star in the constellation Camelopardalis

ST Camelopardalis is a carbon star in the constellation of Camelopardalis. It has a radius of 244 R.

R Fornacis Variable star in the constellation Fornax

R Fornacis is a Mira variable and carbon star located in the constellation Fornax. It is around 1,800 light years away based on parallax measurements.

References

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  7. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv: 1606.08053 . Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID   119231169.
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  9. 1 2 Alksnis, A.; Balklavs, A.; Dzervitis, U.; Eglitis, I. (1998). "Absolute magnitudes of carbon stars from HIPPARCOS parallaxes". Astronomy and Astrophysics. 338: 209. Bibcode:1998A&A...338..209A.
  10. De Beck, E.; Decin, L.; De Koter, A.; Justtanont, K.; Verhoelst, T.; Kemper, F.; Menten, K. M. (2010). "Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles. II. CO line survey of evolved stars: Derivation of mass-loss rate formulae". Astronomy and Astrophysics. 523: A18. arXiv: 1008.1083 . Bibcode:2010A&A...523A..18D. doi:10.1051/0004-6361/200913771. S2CID   16131273.
  11. 1 2 3 4 5 Kerschbaum, F.; Ladjal, D.; Ottensamer, R.; Groenewegen, M. A. T.; Mecina, M.; Blommaert, J. A. D. L.; Baumann, B.; Decin, L.; Vandenbussche, B.; Waelkens, C.; Posch, T.; Huygen, E.; De Meester, W.; Regibo, S.; Royer, P.; Exter, K.; Jean, C. (2010). "The detached dust shells of AQ Andromedae, U Antliae, and TT Cygni". Astronomy and Astrophysics. 518: L140. arXiv: 1005.2689 . Bibcode:2010A&A...518L.140K. doi:10.1051/0004-6361/201014633. S2CID   55820070.
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