Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Taurus |
Right ascension | 04h 03m 44.60445s [2] |
Declination | +05° 26′ 08.2258″ [2] |
Apparent magnitude (V) | +5.33 [3] |
Characteristics | |
Spectral type | B3V [4] |
Variable type | Slowly pulsating B-type star [5] |
Astrometry | |
Proper motion (μ) | RA: 1.271±0.275 [2] mas/yr Dec.: −7.216±0.201 [2] mas/yr |
Parallax (π) | 4.5161 ± 0.2637 mas [2] |
Distance | 720 ± 40 ly (220 ± 10 pc) |
Absolute magnitude (MV) | −1.2 [6] |
Details [7] | |
Primary | |
Mass | 4.6 M☉ |
Radius | 2.4 [lower-alpha 1] R☉ |
Luminosity | 560+530 −270 L☉ |
Surface gravity (log g) | 4.2±0.2 cgs |
Temperature | 16,850±800 K |
Metallicity [Fe/H] | −0.3 dex |
Rotation | 5.9±2 d |
Rotational velocity (v sin i) | 21.5±1.5 km/s |
Secondary | |
Mass | 4.2 M☉ |
Radius | 2.9 [lower-alpha 1] R☉ |
Luminosity | 420+540 −230 L☉ |
Surface gravity (log g) | 4.25±0.25 cgs |
Temperature | 16,250±1,000 K |
Metallicity [Fe/H] | −0.3 dex |
Rotation | 1.2±0.6 d |
Rotational velocity (v sin i) | 35±4 km/s |
Age | 40-55 Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 25558, also known as V1133 Tauri and by its Flamsteed designation 40 Tauri, is a star located about 700 light years from the Earth, in the constellation Taurus. [2] Its apparent magnitude is about 5.3, [3] making it faintly visible to the naked eye of an observer far from city lights. It is a variable star, ranging in brightness from Hipparcos magnitude 5.28 to 5.32 over a period of 1.53232423 days. [5]
In 1998, HD 25558 was discovered to be a variable star by Christoffel Waelkens et al. who analyzed the Hipparcos photometric data for hundreds of stars, and classified HD 25558 as a slowly pulsating B star with a period of 1.53 days. [9]
Beginning in 2008, HD 25558 was the subject of an observing campaign by Ádám Sódor et al. who gathered data collected from 17 observatories on the ground and in space. This star was chosen for the project because it is relatively bright, located near the celestial equator (and thus observable from almost anywhere on Earth), and the slow rotation indicated in earlier studies would simplify the interpretation of spectra. The investigators concluded that HD 25558 is a spectroscopic binary with a period of about 8.9 years, but not enough data was available to derive a full description of the orbit. Both components of the binary show detectable stellar pulsations. The primary star rotates with a period of about 6 days, and the secondary rotates in just 1.2 days. The primary has no detectable magnetic field, but the secondary's field strength is at least a few hundred gauss. The dominant 1.53 day pulsation period arises from the primary star and those pulsations were coherent over the 20 year period spanned by the data used in the study. [7]
26 Canis Majoris is a variable star in the southern constellation of Canis Major, located around 1,010 light years away from the Sun. It has the variable star designation MM Canis Majoris; 26 Canis Majoris is the Flamsteed designation. This object is visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of 5.89. It is moving further from the Earth with a heliocentric radial velocity of +22 km/s.
V345 Carinae is a star in the constellation Carina. It has the Bayer designation E Carinae; V345 Carinae is the variable star designation. The star has a blue-white hue and is faintly visible to the naked eye with an apparent visual magnitude that fluctuates around +4.66. Its actual brightness varies from magnitude +4.67 to +4.78 with a period of 137.7 days. Based on parallax measurements, it is located at a distance of approximately 1,010 light years from the Sun. It is drifting further away with a radial velocity of around +19 km/s.
119 Tauri is a red supergiant star in the constellation Taurus. It is a semiregular variable and its angular diameter has been measured at about 10 mas.
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.
DL Crucis is a variable star in the constellation Crux.
HD 3346, also known as V428 Andromedae, is a binary star system in the northern constellation of Andromeda. It is a dim star but visible to the naked eye under suitable viewing conditions, having an apparent visual magnitude of 5.14. The distance to HD 3346 can be determined from its annual parallax shift of 4.72 mas. This yields a range of about 690 light-years. At that distance the brightness of the system is diminished by an extinction of 0.16 magnitude due to interstellar dust. It is moving closer to the Earth with a heliocentric radial velocity of −33 km/s.
V1472 Aquilae is a triple star system in the equatorial constellation of Aquila. It is a variable star that ranges in brightness from 6.36 down to 6.60. The system is located at a distance of approximately 780 light years from the Sun based on parallax. It is a high-velocity star system with a radial velocity of −112 km/s.
V381 Cephei is a triple star system in the northern constellation of Cepheus. Its apparent magnitude is slightly variable between 5.5 and 5.7.
W Virginis is the prototype W Virginis variable, a subclass of the Cepheid variable stars. It is located in the constellation Virgo, and varies between magnitudes 9.46 and 10.75 over a period of approximately 17 days.
54 Eridani is a suspected astrometric binary star system located around 400 light years from the Sun in the equatorial constellation of Eridanus. It is visible to the naked eye as a faint, reddish hued star with a baseline apparent visual magnitude of 4.32. The object is moving closer to the Earth with a heliocentric radial velocity of −33 km/s.
104 Herculis is a solitary variable star located around 560 light years away from the Sun in the northern constellation of Hercules. It has the variable star designation V669 Herculis and the Bayer designation A Herculis, while 104 Herculis is the Flamsteed designation. This object is visible to the naked eye as a dim, red-hued point of light with a baseline apparent visual magnitude of 4.96. It is moving closer to the Earth with a heliocentric radial velocity of −1.2 km/s.
53 Persei is a single variable star in the northern constellation of Perseus. It has the Bayer designation d Persei, while 53 Persei is the Flamsteed designation. The star is visible to the naked eye as a faint, blue-white hued point of light with an apparent visual magnitude of 4.80. It is located approximately 480 light years away from the Sun, as determined from parallax, and is drifting further away with a radial velocity of +7.3 km/s.
AZ Canis Minoris is a variable star in the equatorial constellation of Canis Minor. It is just visible to the naked eye in good viewing conditions as a dim, white-hued star with an apparent visual magnitude of around 6.46. The star is located around 500 light years away from the Sun based on parallax, and is drifting further away with a radial velocity of +15 km/s. No evidence has been found for a companion to this star, although in the past it has been reported as a binary star system.
HY Velorum is a binary star system in the southern constellation of Vela. It is a dim star but visible to the naked eye with an apparent visual magnitude of 4.83. The distance to this system, as estimated from its annual parallax shift of 7.1 mas, is 460 light years. HY Vel most likely forms a gravitationally bound pair with the magnitude 5.45 binary system KT Vel ; both are members of the IC 2391 open cluster. As of 1998, HY Vel and KT Vel had an angular separation of 76.1″ along a position angle of 311°.
GX Velorum is a solitary variable star in the southern constellation of Vela. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude that fluctuates around 4.99. Based upon parallax measurements, it is located approximately 4,200 light years distant from the Sun, and is drifting further away with a radial velocity of +28 km/s. It may be a member of the Vela OB1 association of co-moving stars.
V4199 Sagittarii is a variable star in the southern constellation of Sagittarius. It is a dim star that is just visible to the naked eye with an apparent visual magnitude that varies between 6.22 and 6.28 over a period of 1.23825 days. The star is located at a distance of approximately 689 light years from the Sun based on parallax, but is drifting closer with a radial velocity of roughly −23 km/s. It has an absolute magnitude of −0.63, on average.
Psi2 Orionis a binary star system in the equatorial constellation of Orion. It has an apparent visual magnitude of 4.6, indicating that it is visible to the naked eye. Based upon an annual parallax shift of 2.87 mass, it is roughly 1,100 light years distant from the Sun.
GP Andromedae is a Delta Scuti variable star in the constellation Andromeda. It is a pulsating star, with its brightness varying with an amplitude of 0.55 magnitudes around a mean magnitude of 10.7.
Rho Phoenicis is a variable star in the constellation of Phoenix. From parallax measurements by the Gaia spacecraft, it is located at a distance of 245 light-years from Earth.
V538 Carinae is a variable star in the constellation of Carina, and a possible red supergiant. If this star replaced the Sun in the Solar System, its photosphere would at least engulf the orbit of Mars.