1 Camelopardalis

1 Camelopardalis (1 Cam) is a double star system in the constellation Camelopardalis. Its combined apparent magnitude is 5.56 and it is approximately 800 parsecs (2,600 ly) away. It is faintly visible to the naked eye under good observing conditions.

1 Camelopardalis

Location of 1 Camelopardalis (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Camelopardalis
1 Cam A
Right ascension	04h 32m 01.841s[1]
Declination	+53° 54′ 39.02″[1]
Apparent magnitude (V)	5.77[2]
1 Cam B
Right ascension	04h 32m 00.915s[3]
Declination	+53° 54′ 45.35″[3]
Apparent magnitude (V)	6.803[2]
Characteristics
1 Cam A
Spectral type	O9.7IIn[4]
U−B color index	−0.73[5]
B−V color index	+0.18[5]
Variable type	SPB?[6]
1 Cam B
Spectral type	B1IV:[7]
U−B color index	−0.70[5]
B−V color index	+0.16[5]
Astrometry
1 Cam A
Proper motion (μ)	RA: +2.775[1] mas/yr Dec.: −3.783[1] mas/yr
Parallax (π)	1.2630 ± 0.0486 mas[1]
Distance	2,580 ± 100 ly (790 ± 30 pc)
1 Cam B
Proper motion (μ)	RA: +0.775[3] mas/yr Dec.: −3.211[3] mas/yr
Parallax (π)	1.1211 ± 0.0462 mas[3]
Distance	2,900 ± 100 ly (890 ± 40 pc)
Absolute magnitude (MV)	−5.53[8]
Details
1 Cam A
Luminosity	4,365[9] L☉
Surface gravity (log g)	3.65[9] cgs
Temperature	29,800[9] K
Rotational velocity (v sin i)	275[10] km/s
1 Cam B
Luminosity	1,995[11] L☉
Temperature	29,512[11] K
Rotational velocity (v sin i)	11[11] km/s
Age	<20[8] Myr
Other designations
DL Camelopardalis, HR 1417, HD 28446, SAO 24672, BD+53°779, FK5 165, WDS J04320+5355, HIP 21148
Database references
SIMBAD	data
	1 Cam A
	1 Cam B

The 1 Camelopardalis system is part of the Camelopardalis OB1 stellar association, which is 820 pc away.^[12] 1 Camelopardalis A is a hot massive star which has evolved away from the main sequence to become a giant. 1 Camelopardalis B is 10" away and is probably an early B class subgiant.

There is an 11th magnitude star 150" away.^[13] It has been considered to be a member of a triple system,^[12] but Gaia observations show it to be an unrelated background object.^[14]

A light curve for DL Camelopardalis, plotted from TESS data^[15]

In 1982, Mikołaj Jerzykiewicz and Christiaan L. Sterken reported that 1 Camelopardalis might be a variable star,^[16] but some subsequent studies failed to confirm that.^[17] Its brightness was convincingly shown to be variable when the Hipparcos data was analyzed. It was given its variable star designation, DL Camelopardalis, in 1999.^[18] 1 Camelopardalis A is a variable star with a small amplitude. It has a likely period of 0.22132 days and is thought to be a β Cephei variable or slowly pulsating B-type star.^[19] Hipparcos photometry shows an amplitude of 0.035 magnitudes.^[20] It has a rotational velocity of 275 km/s, one of the highest known.^[10]

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. Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H.
3. 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.
4. Sota, A; Apellániz, J. Maíz; Morrell, N. I; Barbá, R. H; Walborn, N. R; Gamen, R. C; Arias, J. I; Alfaro, E. J (2014). "The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars". The Astrophysical Journal Supplement Series. 211 (1): 10. arXiv:1312.6222. Bibcode:2014ApJS..211...10S. doi:10.1088/0067-0049/211/1/10. S2CID 118847528.
5. Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H.
6. 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. Bibcode:2009yCat....102025S.
7. Lutz, T. E; Lutz, J. H (1977). "Spectral classification and UBV photometry of bright visual double stars". The Astronomical Journal. 82: 431. Bibcode:1977AJ.....82..431L. doi:10.1086/112066.
8. Westin, T. N. G. (1985). "The local system of early type stars - Spatial extent and kinematics". Astronomy and Astrophysics Supplement Series. 60: 99. Bibcode:1985A&AS...60...99W.
9. Holgado, G.; Simón-Díaz, S.; Haemmerlé, L.; Lennon, D. J.; Barbá, R. H.; Cerviño, M.; Castro, N.; Herrero, A.; Meynet, G.; Arias, J. I. (2020). "The IACOB project. VI. On the elusive detection of massive O-type stars close to the ZAMS". Astronomy and Astrophysics. 638: A157. arXiv:2005.05446. Bibcode:2020A&A...638A.157H. doi:10.1051/0004-6361/202037699. S2CID 218596165.
10. Cazorla, Constantin; et al. (2017). "Chemical abundances of fast-rotating massive stars. I. Description of the methods and individual results". Astronomy and Astrophysics. 603: A56. arXiv:1703.05592. Bibcode:2017A&A...603A..56C. doi:10.1051/0004-6361/201629841. S2CID 59499133.
11. Simón-Díaz, S.; Godart, M.; Castro, N.; Herrero, A.; Aerts, C.; Puls, J.; Telting, J.; Grassitelli, L. (2017). "The IACOB project . III. New observational clues to understand macroturbulent broadening in massive O- and B-type stars". Astronomy and Astrophysics. 597: A22. arXiv:1608.05508. Bibcode:2017A&A...597A..22S. doi:10.1051/0004-6361/201628541. S2CID 3478126.
12. Straižys, V.; Laugalys, V. (2007). "Young Stars in the Camelopardalis Dust and Molecular Clouds. I. The Cam OB1 Association". Baltic Astronomy. 16: 167–182. arXiv:0803.2461. Bibcode:2007BaltA..16..167S.
13. Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
14. 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.
15. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
16. Jerzykiewicz, M.; Sterken, C. (April 1982). Light variations in several broad-lined B stars, in: Be stars; Proceedings of the Symposium, Munich, West Germany, April 6-10, 1981. Vol. 98. Dordrecht, D. Reidel Publishing Co. pp. 49–51. Bibcode:1982IAUS...98...49J. Retrieved 30 December 2024.
17. Stagg, Ch. (August 1983). "An Investigation of Short Timescale Variability in 6 Early B Stars" (PDF). Information Bulletin on Variable Stars. 2376: 1–6. Bibcode:1983IBVS.2376....1S. Retrieved 30 December 2024.
18. Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (January 1999). "The 74th Special Name-list of Variable Stars" (PDF). Information Bulletin on Variable Stars. 4659: 1–27. Bibcode:1999IBVS.4659....1K. Retrieved 30 December 2024.
19. Jerzykiewicz, M. (1993). "Three known and twenty-two new variable stars of early spectral type". Astronomy and Astrophysics Supplement Series. 97: 421. Bibcode:1993A&AS...97..421J.
20. Lefèvre, L; Marchenko, S. V; Moffat, A. F. J; Acker, A (2009). "A systematic study of variability among OB-stars based on HIPPARCOS photometry" (PDF). Astronomy & Astrophysics. 507 (2): 1141. Bibcode:2009A&A...507.1141L. doi:10.1051/0004-6361/200912304.