HD 27563

HD 27563, also known by the Bayer designation d Eridani, is a single star in Eridanus, in the direction of the Orion–Eridanus Superbubble,^[11] that is faintly visible to the naked eye at a magnitude of about 5.84. Cowley (1972) classifies this star as spectral type B5III,^[3] but Houk and Swift (1999) catalog it as B7II.^[4]

HD 27563

Location of HD 27563 (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Eridanus
Right ascension	04h 20m 42.8341s[1]
Declination	−07° 35′ 32.986″[1]
Apparent magnitude (V)	5.84[2]
Characteristics
Spectral type	B5III[3] or B7II[4]
Apparent magnitude (U)	5.23
Apparent magnitude (B)	5.710
Apparent magnitude (G)	5.829944
Apparent magnitude (J)	6.026
Apparent magnitude (H)	6.109
Apparent magnitude (K)	6.113
Variable type	SPB[2]
Astrometry
Radial velocity (Rv)	11.20±4.3 km/s
Proper motion (μ)	RA: 3.540 mas/yr[1] Dec.: −2.298 mas/yr[1]
Parallax (π)	3.7763 ± 0.0612 mas[1]
Distance	860 ± 10 ly (265 ± 4 pc)
Absolute magnitude (MV)	−1.05[5]
Details
Mass	4.3[6] M☉
Radius	2.8[7] R☉
Luminosity	687[6] L☉
Surface gravity (log g)	3.69[6] cgs
Temperature	13,315[6] K
Rotational velocity (v sin i)	34[8] km/s
Age	180[9] Myr
Other designations
d Eri, 210 G. Eri, EM Eri, HR 1363, HD 27563, HIP 20271, BD−07 798, TIC 37777866, 2MASS J04204283−0735329[10]
Database references
SIMBAD	data

It was used as a comparison star for 46 Eridani in four separate runs at La Silla Observatory in the 1970s and 1980s,^[12] but in 1989, both stars were found to be variable with similar periods of about four days, and HD 27563 assigned the designation EM Eridani.^[13] Despite the lack of reliable comparisons for EM Eridani, it was found that the power spectrum of its light curve is remarkably noisy, with two or four prominent oscillation periods centered around 3.9215 d,^[13][14] and is classified as a slowly pulsating B-type star.^[15]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
2. Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
3. Cowley, A. (1 November 1972). "Spectral classification of the bright B8 stars". The Astronomical Journal. 77: 750–755. Bibcode:1972AJ.....77..750C. doi:10.1086/111348. ISSN 0004-6256.
4. Houk, N.; Swift, C. (1 January 1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5: 0. Bibcode:1999MSS...C05....0H.
5. Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
6. Fouesneau, M.; Andrae, R.; Dharmawardena, T.; Rybizki, J.; Bailer-Jones, C. A. L.; Demleitner, M. (2022). "Astrophysical parameters from Gaia DR2, 2MASS, and AllWISE". Astronomy and Astrophysics. 662: A125. arXiv:2201.03252. Bibcode:2022A&A...662A.125F. doi:10.1051/0004-6361/202141828. S2CID 245837778.
7. Stassun, Keivan G.; Oelkers, Ryan J.; Pepper, Joshua; Paegert, Martin; De Lee, Nathan; Torres, Guillermo; Latham, David W.; Charpinet, Stéphane; Dressing, Courtney D.; Huber, Daniel; Kane, Stephen R.; Lépine, Sébastien; Mann, Andrew; Muirhead, Philip S.; Rojas-Ayala, Bárbara; Silvotti, Roberto; Fleming, Scott W.; Levine, Al; Plavchan, Peter; the TESS Target Selection Working Group (2018). "The TESS Input Catalog and Candidate Target List". The Astronomical Journal. 156 (3): 102. arXiv:1706.00495. Bibcode:2018AJ....156..102S. doi:10.3847/1538-3881/aad050. S2CID 73582386.
8. Bowman, D. M.; Burssens, S.; Simón-Díaz, S.; Edelmann, P. V. F.; Rogers, T. M.; Horst, L.; Röpke, F. K.; Aerts, C. (2020). "Photometric detection of internal gravity waves in upper main-sequence stars. II. Combined TESS photometry and high-resolution spectroscopy". Astronomy and Astrophysics. 640: A36. arXiv:2006.03012. Bibcode:2020A&A...640A..36B. doi:10.1051/0004-6361/202038224. S2CID 260542391.
9. Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. ISSN 0320-0108. S2CID 255201789.
10. "EM Eri". simbad.u-strasbg.fr. Retrieved 20 May 2023.
11. Welsh, B. Y.; Sallmen, S.; Jelinsky, S. (September 2005). "NaI and CaII absorption components observed towards the Orion-Eridanus Superbubble". Astronomy & Astrophysics. 440 (2): 547–557. Bibcode:2005A&A...440..547W. doi:10.1051/0004-6361:20052691. S2CID 122007577.
12. Mathys, G.; Manfroid, J.; Renson, P. (1 March 1986). "Photometric variability of some early-type stars". Astronomy and Astrophysics Supplement Series. 63: 403–416. Bibcode:1986A&AS...63..403M. ISSN 0365-0138.
13. Manfroid, J. (1 March 1989). "On the Light Curve of HD 27563". Information Bulletin on Variable Stars. 3297: 1. Bibcode:1989IBVS.3297....1M. ISSN 0374-0676.
14. Manfroid, J.; Renson, P. (1 October 1989). "Photometric variations of 46 Eridani and 210 G. Eridani". Astronomy and Astrophysics. 223: 187–195. Bibcode:1989A&A...223..187M. ISSN 0004-6361.
15. Dziembowski, W. A.; Moskalik, P.; Pamyatnykh, A. A. (1 December 1993). "The opacity mechanism in B-type stars - II. Excitation of high-order g-modes in main-sequence stars". Monthly Notices of the Royal Astronomical Society. 265 (3): 588–600. Bibcode:1993MNRAS.265..588D. doi:10.1093/mnras/265.3.588. ISSN 0035-8711.