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 | |
Database references | |
SIMBAD | data |
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]
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]
Zeta Geminorum is a bright star with cluster components, distant optical components and a likely spectroscopic partner in the zodiac constellation of Gemini — in its south, on the left 'leg' of the twin Pollux. It is a classical Cepheid variable star, of which over 800 have been found in our galaxy. As such its regular pulsation and luminosity and its relative proximity means the star is a useful calibrator in computing the cosmic distance ladder. Based on parallax measurements, it is approximately 1,200 light-years from the Sun.
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.
RT Aurigae is a yellow supergiant variable star in the constellation Auriga, about 1,500 light years from Earth.
V399 Carinae is a variable 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.
V533 Carinae is a A-type supergiant and a Alpha Cygni variable star with a mean apparent magnitude of +4.59 in the constellation Carina. It is located at a distance of about 13,000 light years.
HD 95109 is a Classical Cepheid variable, a type of variable star, in the constellation Carina. Its apparent magnitude is 6.86.
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.
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.
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.
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.
FF Aquilae is a classical Cepheid variable star located in the constellation Aquila, close to the border with Hercules. It ranges from apparent magnitude 5.18 to 5.51 over a period of 4.47 days, meaning it is faintly visible to the unaided eye in rural or suburban settings.
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.
V602 Carinae is a red supergiant and variable star of spectral type M3 in the constellation Carina. It is considered to be one of largest known stars, being around 1,000 times larger than the Sun.
Kappa Pavonis is a variable star in the constellation Pavo. It is the brightest W Virginis variable in the sky.
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.
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.
S Muscae is a classical (δ) Cepheid variable star in the constellation Musca about 2,600 light years away.
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.
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.