Article · Wikipedia archive · Last revised Jul 13, 2026

44 Tauri

44 Tauri, also known as HD 1287 and IM Tauri, is a star located about 210 light years from the Earth, in the constellation Taurus. It is a 5th magnitude star, making it faintly visible to the naked eye of an observer located far from city lights. It is a Delta Scuti variable star, ranging between magnitude 5.37 and 5.58 over a period of about 3.5 hours.

Last revised
Jul 13, 2026
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44 Tauri

A light curve for IM Tauri, plotted from TESS data.1 The 3.479 hour period2 is marked in red.
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Taurus
Right ascension 04h 10m 49.86084s3
Declination +26° 28′ 51.4365″3
Apparent magnitude (V) 5.37 - 5.584
Characteristics
Evolutionary stage main sequence35
Spectral type F2 IV6
Variable type δ Scuti4
Astrometry
Radial velocity (Rv)17.43±0.643 km/s
Proper motion (μ) RA: −30.919±0.1233 mas/yr
Dec.: −35.105±0.0723 mas/yr
Parallax (π)15.4199±0.0863 mas3
Distance212 ± 1 ly
(64.9 ± 0.4 pc)
Absolute magnitude (MV)1.44±0.167
Details
Primary
Mass1.897 M☉
Surface gravity (log g)3.6±0.16 cgs
Temperature7000±2008 K
Rotational velocity (v sin i)2±18 km/s
Other designations
p Tauri, IM Tauri, BD+26 411, HIP 19513, HD 26322, HR 1287, SAO 764859
Database references
SIMBADdata

44 Tauri, also known as HD 1287 and IM Tauri, is a star located about 210 light years from the Earth, in the constellation Taurus.3 It is a 5th magnitude star, making it faintly visible to the naked eye of an observer located far from city lights. It is a Delta Scuti variable star, ranging between magnitude 5.37 and 5.58 over a period of about 3.5 hours.4

In 1966, Ivan Danziger and Robert Dickens discovered that 44 Tauri was a low amplitude variable star, with a period of approximately 3.22 hours.10 In a follow-up study published the next year, they reported that the period was irregular, indicating beat phenomena, and they classified it as a δ Scuti variable.11 In 1968, 44 Tauri was given the variable star designation IM Tauri.12

44 Tauri has been a popular object for detailed astroseismic and spectroscopic studies, because its very slow (relative to other δ Scuti stars) rotation speed of 3±2 km/sec does not complicate pulsation mode identification or greatly broaden spectral lines.6813 As of 2010, 44 Tauri had been found to pulsate with 15 independent periods, ranging from 1.89 to 4.52 hours.6

References

References

  1. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 16 January 2023.
  2. "IM Tau". The International Variable Star Index. AAVSO. Retrieved 19 January 2023.
  3. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  4. Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
  5. Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy & Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. S2CID 55586789.
  6. Lenz, P.; Pamyatnykh, A. A.; Zdravkov, T.; Breger, M. (January 2010). "A δ Scuti star in the post-MS contraction phase: 44 Tauri". Astronomy and Astrophysics. 509: A90. arXiv:0911.4339. Bibcode:2010A&A...509A..90L. doi:10.1051/0004-6361/200912914. S2CID 119311255.
  7. Civelek, R.; Kızıloğlu, N.; Kırbıyık, H. (October 2001). "Radial and Nonradial Oscillations of 44 Tauri". The Astronomical Journal. 122 (4): 2042–2046. Bibcode:2001AJ....122.2042C. doi:10.1086/323078. hdl:11511/66296. S2CID 122087742.
  8. Lenz, P.; Pamyatnykh, A. A.; Zdravkov, T.; Breger, M. (August 2007). "High-resolution spectroscopy of the δ Scuti star 44 Tauri: photospheric element abundances and mode identification". Astronomy and Astrophysics. 471 (1): 237–245. arXiv:0911.4339. Bibcode:2010A&A...509A..90L. doi:10.1051/0004-6361/200912914. S2CID 119311255.
  9. "p Tau -- delta Sct Variable". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-01-19.
  10. Danziger, I. J.; Dickens, R. J. (August 1966). "Observations of Variable F-Type Stars with Short Periods". Information Bulletin on Variable Stars. 150: 1. Bibcode:1966IBVS..150....1D.
  11. Danziger, I. J.; Dickens, R. J. (July 1967). "Spectrophotometry of New Short-Period Variable Stars". Astrophysical Journal. 149: 55–72. Bibcode:1967ApJ...149...55D. doi:10.1086/149231.
  12. Kukarkin, B. V.; Efremov, Yu. N.; Frolov, M. S.; Medvedeva, G. I.; Kholopov, P. N.; Kurochkin, N. E.; Kukarkina, N. P.; Perova, N. B.; Fedorovich, V. P. (November 1968). "Identification List of the New Variable Stars Nominated in 1968". Information Bulletin on Variable Stars. 311: 1. Bibcode:1968IBVS..311....1K.
  13. Zima, W.; Lehmann, H.; Stütz, Ch.; Ilyin, I. V.; Breger, M. (August 2007). "High-resolution spectroscopy of the δ Scuti star 44 Tauri: photospheric element abundances and mode identification". Astronomy and Astrophysics. 471 (1): 237–245. Bibcode:2007A&A...471..237Z. doi:10.1051/0004-6361:20077201.