HD 25558

HD 25558

A light curve for V1133 Tauri, plotted from TESS data.[1] The 1.53 day period is marked in red.
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]
Distance720 ± 40 ly
(220 ± 10 pc)
Absolute magnitude (MV)−1.2[6]
Details[7]
Primary
Mass4.6 M☉
Radius2.4[a] R☉
Luminosity560+530
−270 L☉
Surface gravity (log g)4.2±0.2 cgs
Temperature16,850±800 K
Metallicity [Fe/H]−0.3 dex
Rotation5.9±2 d
Rotational velocity (v sin i)21.5±1.5 km/s
Secondary
Mass4.2 M☉
Radius2.9[a] R☉
Luminosity420+540
−230 L☉
Surface gravity (log g)4.25±0.25 cgs
Temperature16,250±1,000 K
Metallicity [Fe/H]−0.3 dex
Rotation1.2±0.6 d
Rotational velocity (v sin i)35±4 km/s
Age40-55 Myr
Other designations
40 Tauri, V1133 Tau, BD+05 584, HIP 18957, HR 1253, SAO 111585[8]
Database references
SIMBADdata

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]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference dr3 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Ducati2002 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference lesh1968 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference IVSI was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference schulz2019 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Sódor2014 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Waelkens1998 was invoked but never defined (see the help page).


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