Astronomy:MOA-2010-BLG-477L

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Short description: Star in the constellation Sagittarius
MOA-2010-BLG-477L
Observation data
Equinox J2000.0]] (ICRS)
Constellation Sagittiarus
Right ascension  18h 06m 7.44s[1]
Declination −31° 24′ 16.12″[1]
Characteristics
Evolutionary stage white dwarf[2]
Variable type unknown
Astrometry
Distance7500 ± 2000[3] ly
(2300 ± 600[3] pc)
Details
Mass0.53±0.11[2] M
Other designations
MOA 2010-BLG-477, MOA 2010-BLG-477L, MOA-2010-BLG-477 L
Database references
SIMBADThe star
planet b

MOA-2010-BLG-477L is a star whose existence was detected when it caused a microlensing event in August, 2010. The microlensing event also revealed the existence of a planet orbiting the star. At first the star was thought to be about 0.67 times the mass of the Sun,[1] in the main-sequence phase of its stellar evolution.[1][3] But by the time the star should have been separated enough in the sky from the source star of the microlensing event it was not detected, implying that it is actually a dim white dwarf star.[2]

Planetary system

The MOA-2010-BLG-477L planetary system[3]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 1.5−0.3+1.8 MJ 2−1+3

The history of the detection of the planet, MOA-2010-BLG-477 L b, dates back to the year 2010. In that year, a microlensing alert event occurred, before the planet was confirmed conclusively, and was detected independently by the MOA and OGLE collaborations.[1] Following the original microlensing event, astronomers predicted another microlensing peak, which was observed by numerous groups using a wide array of telescopes.[1] One of these telescopes was located in Antarctica, and made the first microlensing detections from that continent; however, the data collected there were too crude to be included in the analysis which eventually confirmed the planet.[1]

The planet was detected by means of microlensing,[1] where gravitational lensing as the planet and its host star pass in front of a background star causes a temporary flare in the amount of light observed, allowing the planet's existence to be known.[1]

Observations from the Keck Observatory in Hawaii allowed a team from Australia and New Zealand to study the system in more detail. They determined that the star was a white dwarf, and that the planet was similar in mass to Jupiter. The gas giant planet was found to be about 2.8 AU, or about 260 million miles, away from the white dwarf star, which is about half the mass of the Sun.[4][5] The discovery of MOA-2010-BLG-477 L b drew significant attention, as it shows a potential scenario for Jupiter's continued orbit around the Sun in the distant future, after the star's own evolution into a white dwarf.[6]

MOA-2010-BLG-477 L b is the only planet which has been detected orbiting MOA-2010-BLG-477 L. Little is known about this planet, with the only characteristics known about this system are the mass of the planet and its projected separation from its host star.[3]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Bachelet, E.; Shin, I.-G.; Han, C.; Fouqué, P.; Gould, A.; Menzies, J. W.; Beaulieu, J.-P.; Bennett, D. P. et al. (2012). "MOA-2010-BLG-477Lb: Constraining the mass of a microlensing planet from microlensing parallax, orbital motion and detection of blended light". The Astrophysical Journal 754 (1): 73. doi:10.1088/0004-637X/754/1/73. Bibcode2012ApJ...754...73B. 
  2. 2.0 2.1 2.2 Blackman, J. W.; Beaulieu, J. P.; Bennett, D. P.; Danielski, C.; Alard, C.; Cole, A. A.; Vandorou, A.; Ranc, C. et al. (2021), "A Jovian analogue orbiting a white dwarf star", Nature 598 (7880): 272–275, doi:10.1038/s41586-021-03869-6, PMID 34646001 
  3. 3.0 3.1 3.2 3.3 3.4 Schneider, Jean (14 October 2021). "Planet MOA-2010-BLG-477L b.". Extrasolar Planets Encyclopaedia. https://exoplanet.eu/catalog/moa_2010_blg_477l_b--1127/. 
  4. Blackman J. W. et al. A Jovian analogue orbiting a white dwarf star // Nature volume 598, pages 272–275, 13 October 2021
  5. Chen Ly (Oct 23, 2021). "Jupiter-like planet survived the death of its star without harm". New Scientist. https://www.newscientist.com/article/2293447-jupiter-like-planet-survived-the-death-of-its-star-without-harm/. 
  6. Ferreira, Becky (2021-10-13). "Astronomers Found a Planet That Survived Its Star's Death" (in en-US). The New York Times. ISSN 0362-4331. https://www.nytimes.com/2021/10/13/science/white-dwarf-planet.html.