36 Tauri

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36 Tauri
Observation data
Epoch J2000        Equinox J2000
Constellation Taurus
Right ascension 04h 04m 21.67333s [1]
Declination +24° 06 21.5720 [1]
Apparent magnitude  (V)5.512 [2]
Characteristics
Spectral type K0II + B7V [3]
Astrometry
Radial velocity (Rv)10.38 ± 0.06 [4]  km/s
Proper motion (μ)RA: -0.54 [1]   mas/yr
Dec.: -14.08 [1]   mas/yr
Parallax (π)2.88 ± 0.43 [1]   mas
Distance approx. 1,100  ly
(approx. 350  pc)
Absolute magnitude  (MV)-1.79 (-1.40 / -0.50) [3]
Orbit [3]
Period (P)7.9412 ± 0.0093 yr
Semi-major axis (a)0.0289 ± 0.0024″
Eccentricity (e)0.683 ± 0.006
Inclination (i)149.4 ± 6.9°
Longitude of the node (Ω)260 ± 15°
Periastron epoch (T) B 1985.092 ± 0.013
Argument of periastron (ω)
(secondary)
287.7 ± 1.6°
Semi-amplitude (K1)
(primary)
8.69 ± 0.12 km/s
Other designations
BD+23° 609, HIP  19009, HR  1252, SAO  76425
36 Tauri A: HD  25555
36 Tauri B: HD  25556
Database references
SIMBAD data

36 Tauri (abbreviated to 36 Tau) is a binary star in the constellation of Taurus. Parallax measurements made by the Hipparcos spacecraft put it at a distance of over 1,000 light years (350 parsecs) from Earth. [1] The combined apparent magnitude of the system is about 5.5, [2] meaning it can barely be seen with the naked eye, according to the Bortle scale.

36 Tauri is a spectroscopic binary. The two stars are close enough that periodic Doppler shifts in their spectra can be made out. In this case, light from both stars can be detected (and they overlap in the spectrum), so it is a double-lined system. The primary star, designated HD 25555, is a K-type bright giant, and the secondary star, designated HD 25556, is a B-type main-sequence star. [3] However, the spectrum has also been interpreted as a G-type star and an A-type main-sequence star. [5] The two stars have been resolved using speckle interferometry and are thought to have similar masses. [3]

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Omicron Tauri Star in the constellation Taurus

ο Tauri, Latinized as Omicron Tauri, is a binary star system in the constellation Taurus, near the constellation border with Cetus. It has a yellow hue and is visible to the naked eye with an apparent visual magnitude of 3.61. It is approximately 191 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −20 km/s. This system has the Flamsteed designation 1 Tauri; Omicron Tauri is the Bayer designation.

Tau Ursae Majoris Binary star in the constellation Ursa Major

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40 Aurigae is a binary star in the constellation Auriga. Its apparent magnitude is 5.345, meaning it can just barely be seen with the naked eye. Based on parallax estimates made by the Hipparcos spacecraft, the system is located some 340 light-years away.

39 Boötis is a triple star system located around 224 light years away from the Sun in the northern constellation of Boötes. It is visible to the naked eye as a faint, yellow-white hued star with a combined apparent magnitude of 5.68. The system is moving closer to the Earth with a heliocentric radial velocity of −31 km/s.

Nu Cancri, Latinized from ν Cancri, is a binary star in the zodiac constellation of Cancer. It is faintly visible to the naked eye with an apparent visual magnitude of +5.46. Based upon an annual parallax shift of 8.31 mas as seen from the Earth, the star is located roughly 390 light years from the Sun.

Xi Cancri is a spectroscopic binary star system in the zodiac constellation of Cancer. It is visible to the naked eye with an apparent visual magnitude of +5.15. Based upon parallax measurements obtained during the Hipparcos mission, it is roughly 370 light-years distant from the Sun.

Omicron Cassiopeiae Star in the constellation Cassiopeia

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Tau Librae, Latinized from τ Librae, is the Bayer designation for a binary star system at the southern edge of the zodiac constellation of Libra. It can be seen with the naked eye, having an apparent visual magnitude of 3.68. The distance to this system is around 367 light years, as determined from an annual parallax shift of 8.89 mas.

88 Tauri, also known as d Tauri, is a multiple star system in the constellation Taurus. It has an apparent magnitude of about 4.25, meaning that it is visible to the naked eye. Based upon parallax measurements made by the Hipparcos spacecraft, the star system is some 156 light-years from the Sun.

Phi Cygni Star in the constellation Cygnus

Phi Cygni, Latinized from φ Cygni, is a binary star system in the northern constellation of Cygnus. It is faintly visible to the naked eye with an apparent visual magnitude of 4.70. The annual parallax shift is 12.25 mas as measured from Earth, which yields a distance estimate of around 266 light years. It is moving further from the Sun with a radial velocity of +4.5 km/s.

Tau<sup>5</sup> Eridani Star in the constellation Eridanus

Tau5 Eridani, Latinized from τ5 Eridani, is a binary star system in the constellation Eridanus. It is visible to the naked eye with a combined apparent visual magnitude of 4.26. The distance to this system, as estimated using the parallax technique, is around 293 light years.

Tau9 Eridani is a binary star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 4.63. The distance to this system can be estimated using the parallax method, which yields a value of roughly 327 light years.

Tau8 Eridani, Latinized from τ8 Eridani, is a binary star system in the constellation Eridanus. It is visible to the naked eye with a combined apparent visual magnitude of 4.65. The distance to this system can be estimated via the parallax method, yielding a value of around 380 light years.

Chi Geminorum is a binary star system in the constellation Gemini, near the western border with Cancer. It can be viewed with the naked eye on a dark night, having an apparent visual magnitude of 4.98. Based upon an annual parallax shift of 12.73 mas, it is located roughly 260 light years from the Sun.

Tau1 Hydrae is a triple star system in the equatorial constellation of Hydra. Based upon the annual parallax shift of the two visible components as seen from Earth, they are located about 18 parsecs (59 ly) from the Sun. The system has a combined apparent visual magnitude of +4.59, which is bright enough to be visible to the naked eye at night.

Zeta<sup>1</sup> Lyrae Star in the constellation Lyra

Zeta1 Lyrae, Latinized from ζ1 Lyrae, is a binary star in the northern constellation of Lyra. Based upon an annual parallax shift of 20.89 mas as seen from Earth, the pair are located about 156 light years from the Sun. It is visible to the naked eye with an apparent visual magnitude of 4.37.

ω Leonis, is a star located in the zodiac constellation of Leo. It is visible to the naked eye in the absence of light pollution, with an apparent visual magnitude of about 5.4. The distance to this star, as determined using parallax measurements, is around 108 light years from the Sun. Because of its location close to the ecliptic, it is subject to being obscured by the Moon, and potentially by planets.

HD 163840 is a binary star system in the northern constellation of Hercules. It has a combined apparent visual magnitude of 6.45, which falls just below the brightness level that is visible to the naked eye for people with normal eyesight. An annual parallax shift of 35.40 mas provides a distance estimate of about 92 light years. The system is moving closer to the Sun with a radial velocity of −33 km/s. In about 769,000 years, it will make perihelion at a separation of around 27.2 ly (8.33 pc).

HD 205877 is a visual binary star system in the constellation Indus. It also a double lined spectroscopic binary. The components are very similar and both are located on the giant branch in the Hertzsprung–Russell diagram in agreement with the F7III spectral type.

References

  1. 1 2 3 4 5 6 van Leeuwen, F.; et al. (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 Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
  3. 1 2 3 4 5 Mason, Brian D.; McAlister, Harold A.; Hartkopf, William I.; Griffin, R. F.; Griffin, R. E. M. (1997). "Binary Star Orbits from Speckle Interferometry. X. Speckle-Spectroscopic Orbits of HR 233, 36 Tau, and 73 Leo". The Astronomical Journal. 114: 1607. Bibcode:1997AJ....114.1607M. doi:10.1086/118592.
  4. Pourbaix, D.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv: astro-ph/0406573 . Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID   119387088.
  5. Abt, H. A. (1981). "Visual multiples. VII - MK classifications". The Astrophysical Journal Supplement Series. 45: 437. Bibcode:1981ApJS...45..437A. doi:10.1086/190719.