RT Andromedae

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RT Andromedae
RT Andromedae system.png
RT Andromedae system.
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Andromeda
Right ascension 23h 11m 10.099s [1]
Declination +53° 01 33.04 [1]
Apparent magnitude  (V)9.043 [2]
Characteristics
Spectral type F8-G0V + K1-3V [3]
Variable type RS CVn
Astrometry
Radial velocity (Rv)0.60±0.6 [4]  km/s
Proper motion (μ)RA: -7.01 [1]   mas/yr
Dec.: -20.80 [1]   mas/yr
Parallax (π)10.1267 ± 0.0424  mas [5]
Distance 322 ± 1  ly
(98.7 ± 0.4  pc)
Absolute bolometric
magnitude
 (Mbol)
5.707 / 4.079 [6]
Orbit [7] [6]
Period (P)0.62893095 ± 0.00000009 d
Semi-major axis (a)0.01787 AU (3.839 R)
Eccentricity (e)0.0049 ± 0.0005
Inclination (i)87.26 ± 0.07°
Periastron epoch (T)JD 2436697.857
Details [6]
RT And A
Mass 1.088 ± 0.030  M
Radius 1.286 ± 0.011  R
Temperature 6,150 ± 132  K
RT And B
Mass 0.837 ± 0.030  M
Radius 0.956 ± 0.012  R
Temperature 4,780  K
Other designations
RT And, GSC 03998-02167, HIP 114484, TYC 3998-2167-1, BD+52° 3383a, GCRV 14555, 2MASS J23111009+5301330
Database references
SIMBAD data

RT Andromedae is a variable star in the constellation of Andromeda. The system is estimated to be 322 light-years (98.7 parsecs) away. [3]

The Infrared (K band) light curve of RT Andromedae plotted from data presented in Arevalo & Lazaro (1995) RTAndLightCurve.png
The Infrared (K band) light curve of RT Andromedae plotted from data presented in Arévalo & Lázaro (1995)

RT Andromedae is classified as a RS Canum Venaticorum variable, a type of close eclipsing binary star. It varies from an apparent visual magnitude of 9.83 at minimum brightness to a magnitude of 8.97 at maximum brightness, with a period of 0.6289216 days. [9] The system consists of a G-type main-sequence star slightly more massive than the Sun, and a K-type main-sequence star slightly less massive; the light curve of this eclipsing binary exhibits secular variations of period and minima. [3]

Presence of a third body

According to Pribulla et al. (2000), the changes in variability could be ascribed to a third object in the system, with even a possible fourth. Its minimum mass is estimated to be 5 percent the mass of the Sun (roughly 50 times the mass of Jupiter), with an orbital period close to 75 years and an eccentricity that is thought to be fairly high (at 0.56). [3] Such an object could likely turn out to be a brown dwarf or even a massive jovian planet. However, a recent paper of Manzoori (2009) noticed that there is a decreasing trend in the orbital period, so magnetic braking could explain better the evolution of this orbital system. [6]

Related Research Articles

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<span class="mw-page-title-main">2 Andromedae</span> Binary star system in the constellation Andromeda

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36 Andromedae is a visual binary star system in the northern constellation of Andromeda. The designation is from the star catalogue of English astronomer John Flamsteed, first published in 1712. It is faintly visible to the naked eye with an apparent visual magnitude of 5.45. An annual parallax shift of 26.33 mas yields a distance estimate of about 124 light years. The system is moving closer to the Sun with a radial velocity of −0.8 km/s.

<span class="mw-page-title-main">9 Andromedae</span> Star in the constellation Andromeda

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<span class="mw-page-title-main">AR Aurigae</span> Binary star system in the constellation Auriga

AR Aurigae, also known by its Flamsteed designation 17 Aurigae, is a binary star in the constellation Auriga. Based on parallax measurements made by the Hipparcos spacecraft, it is approximately 461 light-years from Earth.

<span class="mw-page-title-main">42 Capricorni</span> Binary star system in the constellation Capricornus

42 Capricorni is a binary star system in the zodiac constellation of Capricornus. It has a combined apparent visual magnitude of 5.18, so it is faintly visible to the naked eye. Its annual parallax shift of 30.09 mas yields a distance estimate of about 108 light years; the system is moving closer to the Sun with a radial velocity of −1.2 km/s. 42 Capricorni is 0.2 degree south of the ecliptic and so is subject to lunar occultations.

<span class="mw-page-title-main">ET Andromedae</span> Star in the constellation Andromeda

ET Andromedae is a binary star system star in the northern constellation of Andromeda. It has an apparent visual magnitude of 6.48, placing it at the nominal limit for visibility with the naked eye. The distance to this system can be estimated from its annual parallax shift of 5.42 mas, which yields a value of 602 light years.

<span class="mw-page-title-main">V1191 Cygni</span> Star in the constellation Cygnus

V1191 Cygni is the variable star designation for an overcontact binary star system in the constellation Cygnus. First found to be variable in 1965, it is a W Ursae Majoris variable with a maximum apparent magnitude 10.82. It drops by 0.33 magnitudes during primary eclipses with a period of 0.3134 days, while dropping by 0.29 magnitudes during secondary eclipses. The primary star, which is also the cooler star, appears to have a spectral type of F6V, while the secondary is slightly cooler with a spectral type of G5V. With a mass of 1.29 solar masses and a luminosity of 2.71 solar luminosities, it is slightly more massive and luminous than the sun, while the secondary is only around 1/10 as massive and less than half as luminous. With a separation of 2.20 solar radii, the mass transfer of about 2×10−7 solar masses per year from the secondary to the primary is one of the highest known for a system of its type.

<span class="mw-page-title-main">16 Lacertae</span> Triple star system in the constellation Lacerta

16 Lacertae is a triple star system in the northern constellation of Lacerta, located about 1,580 light years from the Sun. It has the variable star designation EN Lacertae; 16 Lacertae is the Flamsteed designation. This system is visible to the naked eye as a faint blue-white hued star with a maximum apparent visual magnitude of +5.587. It is moving closer to the Earth with a heliocentric radial velocity of –12 km/s.

<span class="mw-page-title-main">TW Andromedae</span> Star in the constellation Andromeda

TW Andromedae is an eclipsing binary star, classified also as an Algol variable star, in the constellation Andromeda. Its brightness varies with a period of 4.12 days, and has a typical brightness of magnitude 8.98 but decreasing down to a magnitude of 11.04 during the main eclipse.

<span class="mw-page-title-main">AB Andromedae</span> Binary star in the Andromeda constellation

AB Andromedae is a binary star in the constellation Andromeda. Paul Guthnick and Richard Prager discovered that the star is an eclipsing binary in 1927. Its maximum apparent visual magnitude is 9.49 but shows a variation in brightness down to a magnitude of 10.46 in a periodic cycle of roughly 8 hours. The observed variability is typical of W Ursae Majoris variable stars, so the two stars in this system form a contact binary.

<span class="mw-page-title-main">AD Andromedae</span> Eclipsing binary star in the constellation Andromeda

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<span class="mw-page-title-main">BX Andromedae</span> Star in the constellation Andromeda

BX Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 8.87. Within a cycle of approximately 14.6 hours, the brightness drops down to a magnitude of 9.53 during the main eclipse, and to a magnitude of 9.12 during the secondary one. It is classified as a Beta Lyrae variable.

<span class="mw-page-title-main">CN Andromedae</span> Star in the constellation Andromeda

CN Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 9.62 and drops down to a minimum of 10.2 during the main eclipse. It is classified as a Beta Lyrae variable with a period roughly of 0.4628 days.

<span class="mw-page-title-main">QX Andromedae</span> Eclipsing binary star system in the constellation Andromeda

QX Andromedae is an eclipsing binary in the constellation Andromeda. It varies from a maximum apparent visual magnitude of 11.28 to a minimum of 11.50. Since it is impossible to specify the onset time of the eclipses, it is classified as a W Ursae Majoris variable star. It is also observed as an X-ray source and is a member of the open cluster NGC 752.

<span class="mw-page-title-main">VW Leonis Minoris</span> Star system in the constellation Leo Minor

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<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">EQ Tauri</span>

EQ Tauri is a triple star system in the equatorial constellation of Taurus that includes a contact eclipsing binary. The system is too faint to be viewed with the naked eye, having a baseline apparent visual magnitude of 10.5. During the primary eclipse, the brightness of the system drops to magnitude 11.03, then to 10.97 during the secondary minimum. The secondary eclipse is total. Based on parallax measurements, it is located at a distance of approximately 730 light years from the Sun.

<span class="mw-page-title-main">AG Virginis</span> Eclipsing binary star in the constellation Virgo

AG Virginis is an eclipsing binary star system in the equatorial constellation of Virgo. With a maximum apparent visual magnitude of 8.51 it is too faint to be visible to the naked eye. The system is located at a distance of approximately 820 light years from the Sun 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.

References

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  4. Karataș, Yüksel; Bilir, Selçuk; Eker, Zeki; Demircan, Osman; Liebert, James; Hawley, Suzanne L.; Fraser, Oliver J.; Covey, Kevin R.; Lowrance, Patrick; Kirkpatrick, J. Davy; Burgasser, Adam J. (2004). "Kinematics of chromospherically active binaries and evidence of an orbital period decrease in binary evolution". Monthly Notices of the Royal Astronomical Society. 349 (3): 1069–1092. arXiv: astro-ph/0404219 . Bibcode:2004MNRAS.349.1069K. doi: 10.1111/j.1365-2966.2004.07588.x . S2CID   15290475.
  5. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 .
  6. 1 2 3 4 Manzoori, D. (2009). "Cyclic Variations of Orbital Period and Long-Term Luminosity in Close Binary RT Andromedae". The Astronomical Journal . 138 (6): 1917–1924. Bibcode:2009AJ....138.1917M. doi:10.1088/0004-6256/138/6/1917.
  7. Erdem, A.; Demircan, O.; Güre, M. (2001). "The light and period changes of RT Andromedae". Astronomy & Astrophysics. 379 (3): 878. Bibcode:2001A&A...379..878E. doi: 10.1051/0004-6361:20011357 .
  8. Arevalo, M. J.; Lázaro, C. (September 1995). "Infrared Light Curves and Absolute Parameters of the Active Binary RT Andromedae". The Astronomical Journal. 110 (3): 1376. Bibcode:1995AJ....110.1376A. doi: 10.1086/117611 .
  9. RT And, database entry, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID II/250 Accessed on line 2009-06-22.