Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Puppis |
Right ascension | 07h 13m 32.31810s [1] |
Declination | −44° 38′ 23.0630″ [1] |
Apparent magnitude (V) | 5.10 [2] 2.6–6 (GCVS) [3] 6–8 (1995 – ) [4] |
Characteristics | |
Spectral type | M5IIIe [3] |
U−B color index | +1.24 [2] |
B−V color index | +1.56 [2] |
Variable type | SRb [3] |
Astrometry | |
Radial velocity (Rv) | 33.0 [5] km/s |
Proper motion (μ) | RA: 106.31 [1] mas/yr Dec.: 324.99 [1] mas/yr |
Parallax (π) | 15.61 ± 0.99 mas [1] |
Distance | 210 ± 10 ly (64 ± 4 pc) |
Details | |
Mass | 0.659±0.043 [5] M☉ |
Radius | 123±14 [5] R☉ |
Luminosity | 2,000±17 [5] L☉ |
Surface gravity (log g) | 0.078±0.027 [5] cgs |
Temperature | 3,500±250 [5] K |
Age | 10 [5] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
L2 Puppis (also known as HD 56096) is a giant star in the constellation of Puppis and is located between the bright stars Canopus and Sirius. It is a semi-regular pulsating star.
The designation L2 has a tangled history. This star and another were both labelled with "L" by Nicolas-Louis de Lacaille when he created the constellation Puppis within Argo Navis. [6] The two stars were labelled as "1.L" and "2.L" by Johann Elert Bode in his star catalogue published in 1801. [7] Later authors used L1 and L2, usually with numeric subscripts (i.e. L1 and L2), [8] but occasionally as superscripts. [9] The subscripted designation is now universally used where typography allows for subscripts. [5] [10]
L2 Puppis was discovered to be variable by Benjamin Apthorp Gould in 1872, [11] and was listed in Uranometria Argentina as 73 G. Puppis with magnitude 5.10v. It has never been given a formal variable star designation, unlike L1 Puppis which is OU Puppis. [12]
L2 Puppis varies in apparent magnitude by about two magnitudes with a period of 140 days. The average brightness also varies slowly over several years so that the total range is given as magnitude 2.6–6.0. Since 1995 the average brightness has dropped so that the 140-day variations are now between about magnitude 6 and 8. [4] [14] The variation in light may be caused by a combination of radial pulsations in the star's atmosphere and by dimming from circumstellar dust. [15]
L2 Puppis is most likely an asymptotic giant branch star that has passed through the main sequence and is evolving to become a white dwarf. It is shedding mass at the rate of about 5×10−7 M☉ per year, forming a circumstellar dust disk and bipolar plumes of gas that are thought to be the start of a "butterfly"-type planetary nebula. [5]
It has been calculated that the mass of L2 Puppis is currently about 0.66 M☉ and its original mass was close to one M☉ about 10 billion years ago. [5] Other calculations give higher masses, for example 2+1
−0.5 M☉, and younger ages such as 1.5 billion years. [10]
A candidate exoplanet has been found orbiting L2 Puppis every 4.69 years at a distance of 2.43 AU . The mass is highly uncertain, at 12 ± 16 MJ, and it might just be a dense clump of gas and dust. [5]
L2 Puppis has a visual 12th-magnitude companion. A hundred years ago, they were separated by about a minute of arc, but different proper motions mean that this is now about 1.5′ . [16]
15 Arietis is a single variable star in the northern constellation of Aries. 15 Arietis is the Flamsteed designation; it also bears the variable star designation AV Arietis. It has an apparent visual magnitude of 5.74, which is just bright enough to be visible to the naked eye from dark suburban skies. An annual parallax shift of 5.84 mas corresponds to a physical distance of approximately 560 light-years from Earth. At that distance, the star's brightness is reduced by 0.33 in magnitude because of extinction from interstellar gas and dust.
R Carinae is a double star in the southern constellation of Carina. The brighter component is a variable star that can be viewed with the naked eye at peak brightness, but is usually too faint to be seen without a telescope, having an apparent visual magnitude that fluctuates around 7.43. This star is located at a distance of approximately 1,300 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +28 km/s.
NO Aurigae is a pulsating variable star in the constellation Auriga. It is an unusually-luminous asymptotic giant branch star about 3,500 light years away.
HD 27245 is a solitary star in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.52, making it faintly visible to the naked eye. Parallax measurements place it approximately 607 light years away from it the Solar System; it is drifting further away with a heliocentric radial velocity of 25.16 km/s.
Omega1 Cygni, Latinized from ω1 Cygni, is the Bayer designation for a solitary star in the northern constellation of Cygnus. It is visible to the naked eye with an apparent visual magnitude of 4.94. Based upon an annual parallax shift of 2.59 mas, it is estimated to lie roughly 1,260 light years from the Sun. Relative to its neighbors, this star has a peculiar velocity of 25.7±2.2 km/s.
9 Pegasi is a supergiant star in the constellation Pegasus. Its apparent magnitude is 4.35.
17 Persei is a single star in the northern constellation of Perseus, located about 390 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.53. This object is moving further from the Earth at a heliocentric radial velocity of +13 km/s.
NS Puppis is an irregular variable star in the constellation Puppis. Its apparent magnitude varies between 4.4 and 4.5.
V Puppis is a star system in the constellation Puppis. Its apparent magnitude is 4.41. There is a binary star system at the center with a B1 dwarf orbiting a B3 subgiant star. They have an orbital period of 1.45 days and a distance of only 15 solar radii apart. However, the system moves back and forth, indicating that there is a massive object orbiting them with a period around 5.47 years. Based on the mass of the object, its lack of a visible spectrum, and circumstellar matter in the system with many heavy elements, it is probably a black hole. However, a follow-up study could not confirm this object, but found signs that there may be a third object which is fainter than the other components.
1 Puppis is a single star in the southern constellation of Puppis. It lies in the northern part of the constellation at a distance of about 790 ly, east of Aludra in Canis Major and just north of the white supergiant, 3 Puppis. This object is visible to the naked eye as a faint, red-hued star with an apparent visual magnitude of 4.59. It is moving further from the Earth with a heliocentric radial velocity of +32.4 km/s.
HD 68601 is a class A7Ib star in the constellation Puppis. Its apparent magnitude is 4.75 and it is approximately 4,200 light years away based on parallax.
KQ Puppis is a spectroscopic binary variable star in the constellation Puppis. A red supergiant star and a hot main sequence star orbit each other every 9,742 days. Its apparent magnitude varies between 4.82 and 5.17.
HD 70555 is a class K2.5II-III star in the constellation Puppis. Its apparent magnitude is 4.83 and it is approximately 1,010 light years away based on parallax.
HD 51799 is a class M1III star in the constellation Puppis. Its apparent magnitude is 4.95 and it is approximately 860 light years away based on parallax.
HD 50235 is a class K5III star located approximately 811 light years away, in the constellation Puppis. Its apparent magnitude is 4.99. HD 50235 made its closest approach to the Sun 7.8 million years ago, at the distance of 137 light years, during which it had an apparent magnitude of 1.13.
Y Centauri or Y Cen is a semiregular variable star in the constellation of Centaurus.
NW Puppis, also known as υ2 Puppis, is a star in the constellation Puppis. Located around 910 light-years distant, it shines with a luminosity approximately 1,108 times that of the Sun and has a surface temperature of 15,000 K. Anamarija Stankov ruled this star out as a Beta Cephei variable.
HD 57197, also known as M Puppis or HR 2789, is a suspected astrometric binary located in the southern constellation Puppis, the poop deck. It has an apparent magnitude of 5.84, making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from the Gaia satellite, the system is estimated to be 629 light years away from the Solar System. The value is poorly constrained, but it appears to be receding with a heliocentric radial velocity of 13 km/s. At its current distance, HD 57197's brightness is diminished by 0.3 magnitudes due to interstellar dust. It has an absolute magnitude of -0.43.
II Lupi is a Mira variable and carbon star located in the constellation Lupus. It is the brightest carbon star in the Southern Hemisphere at 12 μm.
HR 1217 is a variable star in the constellation Eridanus. It has the variable star designation DO Eridani, but this seldom appears in the astronomical literature; it is usually called either HR 1217 or HD 24712. At its brightest, HR 1217 has an apparent magnitude of 5.97, making it very faintly visible to the naked eye for an observer with excellent dark-sky conditions.