R Leonis

Last updated
R Leonis
Leo constellation map.svg
Red circle.svg
Location of R Leonis (circled)
Observation data
Epoch J2000.0        Equinox J2000.0
Constellation Leo
Right ascension 09h 47m 33.4840s [1]
Declination +11° 25 43.823 [1]
Apparent magnitude  (V)4.4 - 11.3 [2]
Characteristics
Spectral type M6e-M8IIIe-M9.5e [2]
Apparent magnitude  (J)−0.7 [3]
B−V color index 1.26
Variable type Mira variable
Astrometry
Proper motion (μ)RA: 6.132 [1]   mas/yr
Dec.: −53.097 [1]   mas/yr
Parallax (π)14.0566 ± 0.8378  mas [1]
Distance 372  ly
(114 [4]   pc)
Details
Mass 0.7 [5]   M
Radius 320 350 [6]   R
Luminosity 3,537 [4]   L
Temperature 2,930 3,080 [6]   K
Other designations
R Leo, HIP 48036, HD 84748, HR 3882, BD+12°2096, SAO 98769
Database references
SIMBAD data

R Leonis is a red giant Mira-type variable star located approximately 370 light years away in the constellation Leo.

Contents

The light curve of R Leonis from AAVSO V band data RLeoLightCurve.png
The light curve of R Leonis from AAVSO V band data

The apparent magnitude of R Leonis varies between 4.31 and 11.65 with a period of 312 days. At maximum it can be seen with the naked eye, while at minimum a telescope of at least 7 cm is needed. The star's effective temperature is estimated to be 2,930 3,080  kelvins and radius spans 320 solar radii (220,000,000 kilometres ; 1.5 astronomical units ), [6] roughly Mars's orbital zone.

Possible planet

Artistic rendering of R Leonis's putative evaporating planetary companion R Leonis evaporating planet.png
Artistic rendering of R Leonis's putative evaporating planetary companion

In 2009 Wiesemeyer et al. [5] proposed that quasi-periodic fluctuations observed for the star R Leonis may be due to the presence of an evaporating substellar companion, probably an extrasolar planet. They have inferred a putative mass for the orbiting body of twice the mass of Jupiter, orbital period of 5.2 years and likely orbital separation of 2.7 astronomical units. If confirmed such a planetary object could likely be an evaporating planet, with a long comet-like trail as hinted by intense SiO maser emissions.

The R Leonis planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b(unconfirmed)≥2 MJ ≥2.718980

Related Research Articles

<span class="mw-page-title-main">Gamma Leonis</span> Binary star in the constellation Leo

Gamma Leonis, also named Algieba, is a binary star system in the constellation of Leo, made up of two red giants. In 2009, a planetary companion around the primary was announced.

83 Leonis, abbreviated 83 Leo, is a binary star system approximately 59 light-years away in the constellation of Leo. The primary star of the system is a cool orange subgiant star, while the secondary star is an orange dwarf star. The two stars are separated by at least 515 astronomical units from each other. Both stars are presumed to be cooler than the Sun.

<span class="mw-page-title-main">Omega Virginis</span> Star in the constellation Virgo

Omega Virginis is a solitary star in the zodiac constellation Virgo. It has an apparent visual magnitude of +5.2, which is bright enough to be faintly visible to the naked eye. Based upon an annual stellar parallax shift of 6.56 milliarcseconds, it is located about 500 light years from the Sun.

<span class="mw-page-title-main">Chi Aquarii</span> Star in the constellation Aquarius

Chi Aquarii, Latinized from χ Aquarii, is the Bayer designation of a star in the equatorial constellation of Aquarius. The distance to this star, based upon parallax measurements with a 7% margin of error, is roughly 610 light-years. It is visible to the naked eye with an apparent visual magnitude of about 5.

<span class="mw-page-title-main">74 Aquarii</span> Triple star system in the constellation Aquarius

74 Aquarii is a triple star system in the constellation of Aquarius. 74 Aquarii is its Flamsteed designation and it also bears the variable star designation HI Aquarii. The combined apparent visual magnitude is 5.8, although it is very slightly variable, and it is located at a distance of 590 light-years from Earth.

<span class="mw-page-title-main">AD Leonis</span> M-type star in the constellation Leo

AD Leonis (Gliese 388) is a red dwarf star. It is located relatively near the Sun, at a distance of 16.2 light-years, in the constellation Leo. AD Leonis is a main sequence star with a spectral classification of M3.5V. It is a flare star that undergoes random increases in luminosity.

<span class="mw-page-title-main">R Cassiopeiae</span> Star in the constellation Cassiopeia

R Cassiopeiae is a variable star in the northern constellation of Cassiopeia. It is located approximately 574 light years distant from the Sun, but is drifting closer with a radial velocity of −23 km/s. This is a pulsating Mira-type variable star with a brightness varies from magnitude +4.4 down to +13.5 with a period of 433.6 days. At its maximum, R Cassiopeiae is visible to the naked eye as a faint, red-hued star.

<span class="mw-page-title-main">R Centauri</span> Variable star in the constellation Centaurus

R Centauri is a Mira variable star in the constellation Centaurus.

<span class="mw-page-title-main">11 Leonis Minoris</span> Star in the constellation Leo Minor

11 Leonis Minoris is a binary star located 36.64 light years away from Earth, in the northern constellation of Leo Minor. It is visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 5.54. The system is moving away from the Earth with a heliocentric radial velocity of +14.4 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.764 arc seconds per annum.

<span class="mw-page-title-main">R Boötis</span> Star in the constellation Boötes

R Boötis is a variable star in the northern constellation of Boötes. Typically the star is too faint to be readily visible to the naked eye, with a brightness that fluctuates between apparent visual magnitudes of 9.98. The distance to this star is approximately 2,150 light years based on parallax measurements. It is drifting closer with a radial velocity of about −58 km/s.

<span class="mw-page-title-main">Xi Leonis</span> Star in the constellation Leo

Xi Leonis is a solitary star in the zodiac constellation of Leo. It has an apparent visual magnitude of 5.0 and is faintly visible to the naked eye. The distance to this star, as determined by parallax measurements, is roughly 229 light years.

<span class="mw-page-title-main">U Orionis</span> Variable star in the constellation Orion

U Orionis is a Mira-type variable star in the constellation Orion. It is a classical long period variable star that has been well observed for over 120 years.

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

DP Leonis is a binary star system in the equatorial constellation of Leo. It is a variable star that ranges in apparent visual magnitude from 17.5 down to 19. The system is located at a distance of approximately 990 light-years from the Sun based on parallax. It is a cataclysmic variable star of the AM Herculis-type also known as polars. The system comprises an eclipsing white dwarf and red dwarf in tight orbit and an extrasolar planet. This eclipsing variable was discovered by P. Biermann and associates in 1982 as the optical counterpart to the EINSTEIN X-ray source E1114+182.

Pi Leonis, Latinised from π Leonis, is a single star in the zodiac constellation Leo. It is a red-hued star that is visible to the naked eye with an apparent visual magnitude of 4.70. This object is located at a distance of some 410 light-years from the Sun based on parallax, and is drifting further away with a radial velocity of +22 km/s. Because the star lies near the ecliptic it is subject to occultations by the Moon.

39 Leonis is the Flamsteed designation for a star in the zodiac constellation of Leo. It has an apparent visual magnitude of 5.90, so, according to the Bortle scale, it is faintly visible from suburban skies at night. Parallax measurements show an annual parallax shift of 0.0449″, which is equivalent to a distance of around 72.6 ly (22.3 pc) from the Sun.

ψ Leonis, is a solitary star located in the zodiac constellation of Leo, to the east-northeast of Regulus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.38. Based upon stellar parallax measurements, it is located around 95 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an absorption factor of 0.3 due to interstellar dust.

<span class="mw-page-title-main">S Cassiopeiae</span> Star in the constellation Cassiopeia

S Cassiopeiae is a Mira variable and S-type star in the constellation Cassiopeia. It is an unusually cool star, rapidly losing mass and surrounded by dense gas and dust producing masers.

<span class="mw-page-title-main">HD 111395</span> Star in the constellation Coma Berenices

HD 111395 is a single, variable star in the northern constellation of Coma Berenices. It has the variable star designation LW Com, short for LW Comae Berenices; HD 111395 is the Henry Draper Catalogue designation. The star has a yellow hue and is just bright enough to be barely visible to the naked eye with an apparent visual magnitude that fluctuates around 6.29. Based upon parallax measurements, it is located at a distance of 55.8 light years from the Sun. The star is drifting closer with a radial velocity of −8.9 km/s. It is a member of the Eta Chamaeleontis stellar kinematic group.

<span class="mw-page-title-main">56 Leonis</span> Variable star in the constellation Leo

56 Leonis is a red giant variable star located approximately 390 light years away in the constellation Leo.

<span class="mw-page-title-main">8 Leonis Minoris</span> Star in the constellation of Leo Minor

8 Leonis Minoris is a solitary, red hued star located in the northern constellation Leo Minor. It has an apparent magnitude 5.37, making it faintly visible to the naked eye. Based on parallax measurements from the Gaia satellite, the object is estimated to be 492 light years distant. It is receding with a heliocentric radial velocity of 40 km/s. At its current distance, 8 LMi is diminshed by 0.12 magnitudes due to interstellar dust.

References

  1. 1 2 3 4 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 . Gaia DR2 record for this source at VizieR.
  2. 1 2 "GCVS Query=R Leo". General Catalogue of Variable Stars @ Sternberg Astronomical Institute, Moscow, Russia . Retrieved 2012-08-22.
  3. "V* R Leo". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2012-08-21.
  4. 1 2 McDonald, I.; De Beck, E.; Zijlstra, A. A.; Lagadec, E. (2018). "Pulsation-triggered dust production by asymptotic giant branch stars". Monthly Notices of the Royal Astronomical Society. 481 (4): 4984. arXiv: 1809.07965 . Bibcode:2018MNRAS.481.4984M. doi: 10.1093/mnras/sty2607 . S2CID   118969263.
  5. 1 2 Wiesemeyer; et al. (2009). "Precessing planetary magnetospheres in SiO stars?. First detection of quasi-periodic polarization fluctuations in R Leonis and V Camelopardalis". Astronomy and Astrophysics . 498 (3): 801–810. arXiv: 0809.0359 . Bibcode:2009A&A...498..801W. doi:10.1051/0004-6361/200811242. S2CID   14531031.
  6. 1 2 3 Fedele; et al. (2005). "The K -Band Intensity Profile of R Leonis Probed by VLTI/VINCI". Astronomy and Astrophysics . 431 (3): 1019–1026. arXiv: astro-ph/0411133 . Bibcode:2005A&A...431.1019F. doi:10.1051/0004-6361:20042013. S2CID   15500217.
  7. "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.