HD 84810

Last updated
ℓ Carinae
Carina constellation map.svg
Red circle.svg
Location of l Carinae (circled in red)
Observation data
Epoch J2000.0        Equinox J2000.0
Constellation Carina
Right ascension 09h 45m 14.81122s [1]
Declination −62° 30′ 28.4519″ [1]
Apparent magnitude  (V)3.35 - 4.06 [2]
Characteristics
Spectral type G5 Iab/Ib [3] ; F6Ib-K0Ib [2]
U−B color index +0.76 [4]
B−V color index +1.03 [4]
Variable type Classical Cepheid [2]
Astrometry
Radial velocity (Rv)+3.3 [5]  km/s
Proper motion (μ)RA: −12.88 [1]   mas/yr
Dec.: +8.19 [1]   mas/yr
Parallax (π)2.09 ± 0.29  mas [1]
Distance 498+55
−45 [6]   pc
Absolute magnitude  (MV)−5.22 [7]
Details
Mass 8.4 [3] to 13 [8]   M☉
Radius 169±8 [9]   R☉
Luminosity 11,482 [6]   L☉
Surface gravity (log g)1.5 [10]   cgs
Temperature 5,091 [10]   K
Metallicity [Fe/H]0.30 [10]   dex
Age 31.25 [6]   Myr
Other designations
l Carinae, 2MASS  J09451481-6230284, CD−61°2349, FK5  1254, HD  84810, HIP  47854, HR  3884, IRAS  09438-6216, SAO  250683
Database references
SIMBAD data
ESO - Model Image of Cepheid l Carinae ESO - Model Image of Cepheid L Carinae (by).jpg
ESO - Model Image of Cepheid l Carinae

HD 84810, also known as l Carinae (l Car), is a star in the southern constellation of Carina. Its apparent magnitude varies from about 3.4 to 4.1, making it readily visible to the naked eye and one of the brightest members of Carina. Based upon parallax measurements, it is approximately 1,600 light-years (490 parsecs ) from Earth. [1]

From the characteristics of its spectrum, l Carinae has a stellar classification of G5 Iab/Ib. [3] This indicates the star has reached a stage in its evolution where it has expanded to become a supergiant with 169 times the radius of the Sun. [9] As this is a massive star with 8 [3] –13 [8] times the mass of the Sun, it rapidly burns through its supply of nuclear fuel and has become a supergiant in roughly 17-19 million years, after spending 15–17 million years as a main sequence star. [8]

A light curve for l Carinae, plotted from Hipparcos data LCarLightCurve.png
A light curve for l Carinae, plotted from Hipparcos data

l Carinae is classified as a Cepheid variable star and its brightness varies over an amplitude range of 0.725 in magnitude with a long period of 35.560 days. This unusually long period makes it essential for calibrating the period-luminosity relation for Cepheid variables; additionally, it is one of the nearest Cepheid variables, making it relatively easy to observe. [6] The radial velocity of the star likewise varies by 39 km/s during each pulsation cycle. [12] Its radius varies by about 40 R☉ as it pulsates, reaching maximum size as its brightness is decreasing towards minimum. [6]

It has a compact circumstellar envelope that can be discerned using interferometry. The envelope has been resolved at an infrared wavelength of 10μm, showing a radius of 10–100  AU at a mean temperature of 100 K. The material for this envelope was supplied by mass ejected from the central star. [8]

The period of l Carinae is calculated to be slowly increasing and it is thought to be crossing the instability strip for the third time, cooling as it evolves towards a red supergiant after a blue loop. [6]

Related Research Articles

<span class="mw-page-title-main">X Sagittarii</span> Variable star and possible binary star system in the constellation Sagittarius

X Sagittarii is a variable star and candidate binary star system in the southern constellation of Sagittarius, near the western constellation boundary with Ophiuchus. It has a yellow-white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around 4.54. The star is located at a distance of approximately 950 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −10 km/s. The star has an absolute magnitude of around −2.85.

<span class="mw-page-title-main">RT Aurigae</span> Star in the constellation Auriga

RT Aurigae is a yellow supergiant variable star in the constellation Auriga, about 1,500 light years from Earth.

<span class="mw-page-title-main">V399 Carinae</span> Star in the constellation Carina

V399 Carinae is a variable star in the constellation Carina.

<span class="mw-page-title-main">V382 Carinae</span> Star in the constellation Carina

V382 Carinae, also known as x Carinae, is a yellow hypergiant in the constellation Carina. It is a G-type star with a mean apparent magnitude of +3.93, and a variable star of low amplitude.

<span class="mw-page-title-main">V533 Carinae</span> Star in the constellation Carina

V533 Carinae is a white A-type supergiant variable star with a mean apparent magnitude of +4.59 in the constellation Carina. It is over 10,000 light years from Earth.

<span class="mw-page-title-main">HD 95109</span> Star in the constellation Carina

HD 95109 is a Classical Cepheid variable, a type of variable star, in the constellation Carina. Its apparent magnitude is 6.86.

<span class="mw-page-title-main">Y Carinae</span> Star in the constellation Carina

Y Carinae is a Classical Cepheid variable, a type of variable star, in the constellation Carina. Its apparent magnitude varies from 7.53 to 8.48.

<span class="mw-page-title-main">RS Puppis</span> Variable star in the constellation Puppis

RS Puppis is a Cepheid variable star around 6,000 ly away in the constellation of Puppis. It is one of the biggest and brightest known Cepheids in the Milky Way galaxy and has one of the longest periods for this class of star at 41.5 days.

<span class="mw-page-title-main">V810 Centauri</span> Star in the constellation Centaurus

V810 Centauri is a double star consisting of a yellow hypergiant primary and blue giant secondary. It is a small amplitude variable star, entirely due to the supergiant primary which is visually over three magnitudes brighter than the secondary. It is the MK spectral standard for class G0 0-Ia.

<span class="mw-page-title-main">V636 Scorpii</span> Spectroscopic binary star system in the constellation Scorpius

V636 Scorpii is a multiple star system in the constellation Scorpius, 3,000 light years away. The primary is a Classical Cepheid variable and its visual magnitude varies from 6.4 to 6.9.

<span class="mw-page-title-main">FF Aquilae</span> Star and possible star system in the constellation Aquila

FF Aquilae is a classical Cepheid variable star located in the constellation Aquila. It ranges from apparent magnitude 5.18 to 5.51 over a period of 4.470848 days, meaning it is faintly visible to the unaided eye in rural or suburban settings.

<span class="mw-page-title-main">HR Carinae</span> Star in the constellation Carina

HR Carinae is a luminous blue variable star located in the constellation Carina. It is surrounded by a vast nebula of ejected nuclear-processed material because this star has a multiple shell expanding atmosphere. This star is among the most luminous stars in the Milky Way. It has very broad emission wings on the Balmer lines, reminiscent from the broad lines observed in the spectra of O and Wolf–Rayet stars. A distance of 5 kpc and a bolometric magnitude of -9.4 put HR Car among the most luminous stars of the galaxy.

VX Sagittarii is an asymptotic giant branch star located more than 1.5 kiloparsec away from the Sun in the constellation of Sagittarius. It is a pulsating variable star with an unusually large magnitude range. It is one of the largest stars discovered, with a radius varying between 1,350 and 1,940 solar radii (940,000,000 and 1.35×109 km; 6.3 and 9.0 au). It is the most luminous known AGB star, at bolometric magnitude –8.6, which is brighter than the theoretical limit at –8.0.

<span class="mw-page-title-main">V602 Carinae</span> Star in the constellation Carina

V602 Carinae is a red supergiant and variable star of spectral type of M3 in the constellation Carina. It is one of largest known stars.

<span class="mw-page-title-main">Kappa Pavonis</span> Variable star in the constellation Pavo

Kappa Pavonis is a variable star in the constellation Pavo. It is the brightest W Virginis variable in the sky.

<span class="mw-page-title-main">AX Circini</span> Binary star system in the constellation Circinus

AX Circini is a binary star system in the southern constellation of Circinus. It has a nominal magnitude of 5.91, which is bright enough to be visible to the naked eye. Based upon an annual parallax shift of 1.7 mas, it is located roughly 1,900 light-years from the Earth. The system is moving closer with a heliocentric radial velocity of −21 km/s.

<span class="mw-page-title-main">R Muscae</span> Variable star in the constellation Musca

R Muscae is a yellow-white hued variable star in the southern constellation of Musca. It has a nominal apparent visual magnitude of 6.31, which is near the lower limit of visibility to the naked eye. The distance to this star, as determined from its annual parallax shift of 1.00 mas, is around 3,260 light years.

<span class="mw-page-title-main">S Muscae</span> Star in the constellation Musca

S Muscae is a classical (δ) Cepheid variable star in the constellation Musca about 2,600 light years away.

<span class="mw-page-title-main">CK Carinae</span> Red supergiant star in the constellation Carina

CK Carinae is a variable star in the constellation Carina, the keel of Argo Navis. It is a member of the star association Carina OB1-D, at a distance of around 2,300 parsecs or 7,500 light years.

<span class="mw-page-title-main">SZ Tauri</span>

SZ Tauri is a variable star in the equatorial constellation of Taurus. The brightness of this star varies from an apparent visual magnitude of 6.39 down to 6.69 with a period of 3.149 days, which is near the lower limit of visibility to the naked eye. The distance to this star is approximately 2,070 light years based on parallax measurements. There is some indication this may be a binary system, but the evidence is inconclusive.

References

  1. 1 2 3 4 5 6 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv: 0708.1752 , Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID   18759600.
  2. 1 2 3 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
  3. 1 2 3 4 Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society , 410 (1): 190–200, arXiv: 1007.4883 , Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID   118629873.
  4. 1 2 Madore, B. F. (June 1975), "Photoelectric UBV photometry of Cepheids in the Magellanic Clouds and in the southern Milky Way", Astrophysical Journal Supplement Series, 29: 219–284, Bibcode:1975ApJS...29..219M, doi: 10.1086/190342 .
  5. ↑ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick (eds.), "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and Their Applications, Proceedings from IAU Symposium No. 30, University of Toronto: International Astronomical Union, 30: 57, Bibcode:1967IAUS...30...57E.
  6. 1 2 3 4 5 6 Neilson, Hilding R; Engle, Scott G; Guinan, Edward F; Bisol, Alexandra C; Butterworth, Neil (2016), "The Secret Lives of Cepheids: Evolution, Mass-Loss, and Ultraviolet Emission of the Long-period Classical Cepheid", The Astrophysical Journal, 824 (1): 1, arXiv: 1604.03128 , Bibcode:2016ApJ...824....1N, doi: 10.3847/0004-637X/824/1/1 , S2CID   118642210.
  7. ↑ Fouqué, P.; Arriagada, P.; Storm, J.; Barnes, T. G.; Nardetto, N.; Mérand, A.; Kervella, P.; Gieren, W.; Bersier, D.; Benedict, G. F.; McArthur, B. E. (2007). "A new calibration of Galactic Cepheid period-luminosity relations from B to K bands, and a comparison to LMC relations". Astronomy and Astrophysics. 476 (1): 73–81. arXiv: 0709.3255 . Bibcode:2007A&A...476...73F. doi:10.1051/0004-6361:20078187. S2CID   17687829.
  8. 1 2 3 4 Kervella, P.; Mérand, A.; Gallenne, A. (2009), "The circumstellar envelopes of the Cepheids ℓ Carinae and RS Puppis. Comparative study in the infrared with Spitzer, VLT/VISIR, and VLTI/MIDI", Astronomy and Astrophysics, 498 (2): 425–443, arXiv: 0902.1588 , Bibcode:2009A&A...498..425K, doi:10.1051/0004-6361/200811307, S2CID   14541935.
  9. 1 2 Davis, J.; et al. (April 2009), "Observations of the pulsation of the Cepheid l Car with the Sydney University Stellar Interferometer", Monthly Notices of the Royal Astronomical Society, 394 (3): 1620–1630, arXiv: 0812.4791 , Bibcode:2009MNRAS.394.1620D, doi:10.1111/j.1365-2966.2009.14433.x, S2CID   16697473.
  10. 1 2 3 Luck, R. E. (September 1979), "The chemical compositions of nine southern supergiant stars", Astrophysical Journal, Part 1, 232: 797–806, Bibcode:1979ApJ...232..797L, doi:10.1086/157340.
  11. ↑ "Light Curve", Hipparcos ESA, ESA, retrieved 17 February 2022.
  12. ↑ Klagyivik, P.; Szabados, L. (September 2009), "Observational studies of Cepheid amplitudes. I. Period-amplitude relationships for Galactic Cepheids and interrelation of amplitudes", Astronomy and Astrophysics, 504 (3): 959–972, arXiv: 0908.3561 , Bibcode:2009A&A...504..959K, doi:10.1051/0004-6361/200811464, S2CID   18283579.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.