DM Ursae Majoris

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DM Ursae Majoris
DMUMaLightCurve.png
Visual band light curves for DM Ursae Majoris, adapted from Mohin et al. (1985) [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Ursa Major
Right ascension 10h 55m 43.544s [2]
Declination +60° 28′ 09.72″ [2]
Apparent magnitude  (V)9.29 [3]
Characteristics
Spectral type K0III-IV [4] (K0IV + K5V) [5]
B−V color index 1.014±0.026 [3]
Variable type RS CVn [6]
Astrometry
Radial velocity (Rv)−6.9±1.2 [7]  km/s
Proper motion (μ)RA: −37.912  mas/yr [2]
Dec.: −7.566  mas/yr [2]
Parallax (π)5.3862 ± 0.0157  mas [2]
Distance 606 ± 2  ly
(185.7 ± 0.5  pc)
Absolute magnitude  (MV)3.65 [3]
Orbit [7]
Period (P)7.4920±0.0009 d
Eccentricity (e)0.0 (assumed)
Inclination (i)40 [8] °
Periastron epoch (T)2,443,881.4±0.1  JD
Argument of periastron (ω)
(secondary)		0.0 (assumed)°
Semi-amplitude (K1)
(primary)		27.6 km/s
Details
Primary
Mass ~1.2 [5]   M☉
Radius 6.00 [4]   R☉
Luminosity 4.24 [3]   L☉
Temperature 4,500 [4]   K
Secondary
Mass ~0.7 [5]   M☉
Other designations
2A 1052+606, DM UMa, BD+61°1211, HIP  53425, SAO  15338, PPM  17646 [9]
Database references
SIMBAD data

DM Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated DM UMa. It is sometimes identified by the Bonner Durchmusterung catalogue designation BD +61 1211; DM UMa is the variable star designation. The system has a combined apparent visual magnitude of 9.29, [3] which is too faint to be visible to the naked eye. Based on parallax measurements, the system is located at a distance of approximately 606  light years from the Sun, [2] but it is drifting closer with a heliocentric radial velocity of −7 km/s. [7]

In 1978, the X-ray source designated 2A 1052+606 was initially included in the 2A catalogue of observations by the Ariel 5 satellite. [10] The approximate position of this source was determined using the HEAO-1 satellite, then W. Liller matched it with the candidate star SAO 015338 (later DM UMa). He determined the spectra matches a K-type star with strong H-alpha emission lines. [11] In 1979, this object was shown to be an RS Canum Venaticorum variable (RS CVn) by D. Crampton and associates, which indicated this is a close binary star system where one of the components has an active chromosphere with star spots. [7] DM UMa was the first RS CVn variable to be so classified based on its X-ray emission. [12]

Radial velocity measurements demonstrated an orbital period of about 7.5 days. A mass function of 0.016  M☉ suggested the system is being viewed from a low inclination, close to pole-on. [7] The system showed variations in emission lines on a time scale of a day. [13] A photometric light curve was generated by R. A. Kimble and associates in 1981, showing strong variability within each orbital period. [5] A model fit to the light curve indicated the star has an extensive distribution of star spots, with regions of enhanced spot activity toward and away from the companion. It is one of the few variables of this class that show a continual emission of H-alpha, although this varies by a factor of three over the course of an orbit. [12]

This is a single-lined spectroscopic binary [5] with the spectra matching a stellar classification of K0III-IV. [4] The secondary is at least 1.5 magnitudes fainter than the primary, so the contribution of the former to the luminosity is no more than 20%. [12] The observed properties of the system can be modeled by a combination of a subgiant primary of class K0IV with a K5V main sequence secondary. [5]

Related Research Articles

<span class="mw-page-title-main">W Ursae Majoris</span> Star in the constellation Ursa Major

W Ursae Majoris is the variable star designation for a binary star system in the northern constellation of Ursa Major. It has an apparent visual magnitude of about 7.9, which is too faint to be seen with the naked eye. However, it can be viewed with a small telescope. Parallax measurements place it at a distance of roughly 169 light years (52 parsecs) from Earth.

Kappa Ursae Majoris is a binary star in the constellation of Ursa Major. With a combined apparent magnitude of +3.60, the system is approximately 358 light-years from Earth.

Xi Ursae Majoris is a star system in the constellation of Ursa Major. It has the traditional name Alula Australis; Xi Ursae Majoris is the Bayer designation, which is Latinised from ξ Ursae Majoris and abbreviated Xi UMa or ξ UMa. It was the first visual double star for which an orbit was calculated, when it was computed by Félix Savary in 1828. It is also a variable star with a small amplitude. Xi Ursae Majoris is found in the left hind paw of the Great Bear.

<span class="mw-page-title-main">Omega Ursae Majoris</span> Binary system in the constellation Ursa Major

Omega Ursae Majoris is the Bayer designation for a binary star system in the northern circumpolar constellation of Ursa Major. It is visible to the naked eye with an apparent visual magnitude of 4.61. Based upon an annual parallax shift of 13.24 mas, it is roughly 246 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.11 due to interstellar dust.

<span class="mw-page-title-main">24 Ursae Majoris</span> Star in the constellation Ursa Major

24 Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major, located 101.5 light-years from the Sun. It has the variable star designation DK Ursae Majoris and the Bayer designation d Ursae Majoris; 24 Ursae Majoris is the Flamsteed designation. This object is visible to the naked eye as a faint, yellow-hued star with an apparent visual magnitude of 4.54. It is moving closer to the Earth with a heliocentric radial velocity of −27 km/s, and is expected to come as close as 51 light-years in around 879,000 years.

<span class="mw-page-title-main">SU Ursae Majoris</span> Variable star in the constellation Ursa Major

SU Ursae Majoris, or SU UMa, is a close binary star in the northern circumpolar constellation of Ursa Major. It is a periodic cataclysmic variable that varies in magnitude from a peak of 10.8 down to a base of 14.96. The distance to this system, as determined from its annual parallax shift of 4.53 mas, is 719 light-years. It is moving further from the Earth with a heliocentric radial velocity of +27 km/s.

<span class="mw-page-title-main">RS Canum Venaticorum</span> Binary star in the constellation Canes Venatici

RS Canum Venaticorum is a binary star system in the northern constellation of Canes Venatici. It serves as the prototype to the class of RS Canum Venaticorum variables. The peak apparent visual magnitude of this system is below the level needed to observe it with the naked eye. It is located at a distance of approximately 443 light years from the Sun based on parallax, but is drifting closer with a net radial velocity of −14 km/s. Olin J. Eggen (1991) included this system as a member of the IC 2391 supercluster, but it was later excluded.

<span class="mw-page-title-main">TU Ursae Majoris</span>

TU Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major. It is classified as a Bailey-type 'ab' RR Lyrae variable with a period of 0.557648 days that ranges in brightness from apparent visual magnitude of 9.26 down to 10.24. The distance to this star is approximately 2,090 light years based on parallax measurements. It is located near the north galactic pole at a distance that indicates this is a member of the galactic halo.

<span class="mw-page-title-main">TX Ursae Majoris</span> Eclipsing binary star system in the constellation of Ursa Major

TX Ursae Majoris is an eclipsing binary star system in the northern circumpolar constellation of Ursa Major. With a combined apparent visual magnitude of 6.97, the system is too faint to be readily viewed with the naked eye. The pair orbit each other with a period of 3.063 days in a circular orbit, with their orbital plane aligned close to the line of sight from the Earth. During the primary eclipse, the net brightness decreases by 1.74 magnitudes, while the secondary eclipse results in a drop of just 0.07 magnitude. TX UMa is located at a distance of approximately 780 light years from the Sun based on parallax measurements, but is drifting closer with a mean radial velocity of −13 km/s.

<span class="mw-page-title-main">UX Ursae Majoris</span>

UX Ursae Majoris is an Algol type binary star system in the northern circumpolar constellation of Ursa Major. It is classified as a nova-like variable star similar to DQ Herculis, although no eruptions have been reported. Since its discovery in 1933, this system has been the subject of numerous studies attempting to determine its properties. The combined apparent visual magnitude of UX UMa ranges from 12.57 down to 14.15. The system is located at a distance of approximately 952 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 112 km/s.

<span class="mw-page-title-main">XY Ursae Majoris</span> Eclipsing binary star system in the constellation of Ursa Major

XY Ursae Majoris is a short period binary star system in the northern circumpolar constellation of Ursa Major. It is an eclipsing binary with a baseline apparent visual magnitude of 9.50. The system is located at a distance of 221.5 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −10 km/s. It has a relatively high proper motion, traversing the celestial sphere at the angular rate of 0.191″·yr−1.

<span class="mw-page-title-main">UV Piscium</span> Binary star system in the Pisces constellation

UV Piscium is a binary star system in the constellation of Pisces. With a peak apparent visual magnitude of 8.98, it is too faint to be visible to the naked eye. This is an eclipsing binary system that decreases to magnitude 10.05 during the primary eclipse, then to magnitude 9.54 with the secondary eclipse. It is located at a distance of 232 light years from the Sun based on parallax measurements, and is receding with a radial velocity of 6.5 km/s. The position of this star near the ecliptic means it is subject to lunar occultation.

<span class="mw-page-title-main">SW Ursae Majoris</span> Variable star in the constellation Ursa Major

SW Ursae Majoris is a cataclysmic binary star system in the northern circumpolar constellation of Ursa Major, abbreviated SW UMa. During quiescence it has an apparent visual magnitude of 16.5–17, which is too faint to be visible to the naked eye. Based on parallax measurements, it is located at a distance of approximately 526 light years from the Sun.

<span class="mw-page-title-main">VV Ursae Majoris</span> Variable star system in the constellation Ursa Major

VV Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated VV UMa. It is a variable star system with a brightness that cycles around an apparent visual magnitude of 10.19, making it too faint to be visible to the naked eye. The system is located at a distance of approximately 1,500 light years based on parallax measurements.

<span class="mw-page-title-main">AE Ursae Majoris</span> Variable star in the constellation Ursa Major

AE Ursae Majoris is a star in the northern circumpolar constellation of Ursa Major, abbreviated AE UMa. It is a variable star that ranges in brightness from a peak apparent visual magnitude of 10.86 down to 11.52. The distance to this star is approximately 2,400 light years based on parallax measurements.

<span class="mw-page-title-main">AW Ursae Majoris</span> Variable star in the constellation Ursa Major

AW Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated AW UMa. It is an A-type W Ursae Majoris variable with an apparent visual magnitude of 6.83, which is near the lower limit of visibility to the naked eye. This is an eclipsing binary with the brightness dropping to magnitude 7.13 during the primary eclipse and to 7.08 with the secondary eclipse. Parallax measurements give a distance estimate of 221 light years from the Sun. It is drifting closer to the Sun with a radial velocity of approximately −17 km/s. The system has a high proper motion, traversing the celestial sphere at the rate of 0.216 arc second per annum.

<span class="mw-page-title-main">BE Ursae Majoris</span> Variable star in the constellation Ursa Major

BE Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated BE UMa. The two components are an unusual M-class dwarf star and a subdwarf O star, borderline white dwarf. It is classified as a detached Algol variable and ranges in brightness from an apparent visual magnitude of 14.8 down to 17.8. This is too faint to be visible to the naked eye. The distance to this system is approximately 4,600 light years based on parallax measurements.

<span class="mw-page-title-main">CQ Ursae Majoris</span> Variable star in the constellation Ursa Major

CQ Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major, abbreviated CQ UMa. It is sometimes identified as HR 5153 from the Bright Star Catalogue or HD 119213 in the Henry Draper Catalogue; CQ UMa is the variable star designation. The star ranges in apparent visual magnitude from 6.28 to 6.30, which is bright enough to be dimly visible to the naked eye. It is located at a distance of 296 light years from the Sun based on parallax measurements.

<span class="mw-page-title-main">DW Ursae Majoris</span> Variable star in the constellation Ursa Major

DW Ursae Majoris is an eclipsing binary star system in the northern circumpolar constellation of Ursa Major, abbreviated DW UMa. It is a cataclysmic variable of the SX Sextanis type, consisting of a compact white dwarf that is accreting matter from an orbiting companion star. The brightness of this source ranges from an apparent visual magnitude of 13.6 down to magnitude 18, which is too faint to be viewed with the naked eye. The distance to this system is approximately 1,920 light years based on parallax measurements.

<span class="mw-page-title-main">84 Ursae Majoris</span> Variable star in the constellation Ursa Major

84 Ursae Majoris, also known as HD 120198, is a star about 300 light years from the Earth, in the constellation Ursa Major. It is a 5th magnitude star, making it faintly visible to the naked eye of an observer far from city lights. It is an Ap star with an 1,100 gauss magnetic field, and an α2 CVn variable star, varying in brightness from magnitude 5.65 to 5.70, over a period of 1.37996 days. 84 Ursae Majoris is located just 70 arcseconds from the star LDS 2914, but that star is believed to be a background star not physically associated with 84 Ursae Majoris.

References

  1. ↑ Mohin, S.; Raveendran, A. V.; Mekkaden, M. V.; Hall, D. S.; Henry, G. W.; Lines, R. D.; Fried, R. E.; Louth, H.; Stelzer, H. J. (October 1985). "Evolution of Starspot Regions in DM UMa". Astrophysics and Space Science. 115 (2): 353–368. Bibcode:1985Ap&SS.115..353M. doi:10.1007/BF00653812. S2CID   119914476 . Retrieved 6 October 2022.
  2. 1 2 3 4 5 6 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.
  3. 1 2 3 4 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.
  4. 1 2 3 4 Strassmeier, Klaus G. (September 2009), "Starspots", The Astronomy and Astrophysics Review, 17 (3): 251–308, Bibcode:2009A&ARv..17..251S, doi: 10.1007/s00159-009-0020-6 .
  5. 1 2 3 4 5 6 Kimble, R. A.; et al. (December 1981), "Discovery of a large-amplitude photometric wave in the RS CVn binary BD +61 1211 (=DM UMA) and constraints on starspot models for the observed variation", Astrophysical Journal, 251: 585–590, Bibcode:1981ApJ...251..585K, doi:10.1086/159502.
  6. ↑ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports , 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID   125853869.
  7. 1 2 3 4 5 Crampton, D.; et al. (December 1979), "The RS CVn system BD +61 1211 = 2A 1052+60.6", Astrophysical Journal, 234: 993–996, Bibcode:1979ApJ...234..993C, doi:10.1086/157583, S2CID   120565755.
  8. ↑ Hatzes, Artie P. (January 1995), "Spot and Chromospheric Activity on the RS CVN Star DM Ursae Majoris", Astronomical Journal, 109: 350, Bibcode:1995AJ....109..350H, doi: 10.1086/117280 .
  9. ↑ "DM UMa". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2022-10-01.
  10. ↑ Cooke, B. A.; et al. (February 1978), "The Ariel V (SSI) catalogue of high galactic latitude (|b| > 10°) X-ray sources", Monthly Notices of the Royal Astronomical Society, 182 (3): 489–515, Bibcode:1978MNRAS.182..489C, doi: 10.1093/mnras/182.3.489 .
  11. ↑ Liller, W.; et al. (February 1978), Marsden, B. G. (ed.), "2A 1052+606 = SAO 015338?", IAU Circular, 3176: 2, Bibcode:1978IAUC.3176....2L.
  12. 1 2 3 Rosario, M. J.; et al. (April 2009), "Spot activity in the RS CVn binary DM Ursae Majoris", Monthly Notices of the Royal Astronomical Society, 394 (2): 872–881, Bibcode:2009MNRAS.394..872R, doi:10.1111/j.1365-2966.2008.14372.x, S2CID   123218100.
  13. ↑ Charles, P.; et al. (December 1979), "X-ray and optical variability in 2A1052+606-a new RS CVn-type system", Nature, 282 (5740): 691–692, Bibcode:1979Natur.282..691C, doi:10.1038/282691a0, S2CID   4315279.

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