HD 217107

Last updated

HD 217107
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Pisces
Right ascension 22h 58m 15.5408s [1]
Declination −2° 23′ 43.383″ [1]
Apparent magnitude  (V)+6.17 [2]
Characteristics
Spectral type G8 IV-V [2]
B−V color index 0.744±0.006 [2]
Astrometry
Radial velocity (Rv)−13.4±0.1 [2]  km/s
Proper motion (μ)RA: −6.819(25)  mas/yr [1]
Dec.: −15.040(23)  mas/yr [1]
Parallax (π)49.7846 ± 0.0263  mas [1]
Distance 65.51 ± 0.03  ly
(20.09 ± 0.01  pc)
Absolute magnitude  (MV)4.68 [2]
Details
Mass 0.969 [3]   M☉
Radius 1.2104±0.0195 [3]   R☉
Luminosity 1.0951±0.0338 [3]   L☉
Temperature 5391±40 [3]   K
Metallicity 0.31 [3]
Age 11.9 [3]   Gyr
Other designations
6 G. Piscium, BD−03°5539, FK5  3836, HD  217107, HIP  113421, HR  8734, SAO  146412, CCDM J22583-0224AB [4]
Database references
SIMBAD data

HD 217107 (6 G. Piscium) is a yellow subgiant star approximately 65 light-years away from Earth in the constellation of Pisces (the Fish). Its mass is very similar to the Sun's, although it is considerably older. Two planets have been discovered orbiting the star: one is extremely close and completes an orbit every seven days, while the other is much more distant, taking fourteen years to complete an orbit.

Contents

Distance, age, and mass

HD 217107 is fairly close to the Sun: the Gaia astrometric satellite measured its parallax as 49.7846 Milliarcseconds, which corresponds to a distance of 65.51 light years. [1] Its apparent magnitude is 6.17, making it just barely visible to the naked eye under favourable conditions.

Spectroscopic observations show that its spectral type is G7 or G8, which means its temperature is about 5,000 K. Its mass is thought to be roughly the same as the Sun's, although its estimated age of 7.7 billion years is rather older than the Sun's 4.6 billion years, and it is thought to be beginning to evolve away from the main sequence, having consumed almost all the hydrogen in its core in nuclear fusion reactions. [5]

Planetary system

A study of the radial velocity of HD 217107 carried out in 1998 revealed that its motion along the line of sight varied over a 7.1-day cycle. The period and amplitude of this variation indicated that it was caused by a planetary companion in orbit around the star, with a minimum mass slightly greater than that of Jupiter. [5] The companion planet was designated HD 217107 b.

While most planets with orbital periods of less than 10 days have almost circular orbits, HD 217107 b has a somewhat eccentric orbit, and its discoverers hypothesized that this could be due to the gravitational influence of a second planet in the system at a distance of several astronomical units (AU). [6] Confirmation of the existence of a second planet followed in 2005, when long term observations of the star's radial velocity variations revealed a variation on a period of about eight years, caused by a planet with a mass at least twice that of Jupiter in a very eccentric orbit with a semimajor axis of about 4.3 AU. [7] The second planet was designated HD 217107 c. [8]

The HD 217107 planetary system [9] [10]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b >1.394+0.057
−0.059  MJ 		0.0746+0.0015
−0.0016		7.126853±0.0000120.1272±0.0028——
c >4.09+0.23
−0.224  MJ 		5.94±0.135059.34+52.78
−49.02		0.3991±0.0103——

See also

Related Research Articles

<span class="mw-page-title-main">70 Virginis</span> Star in the constellation Virgo

70 Virginis is a binary star located 59 light years from the Sun in the equatorial constellation of Virgo, near the northern constellation border with Coma Berenices. 70 Virginis is its Flamsteed designation. The star is visible to the naked eye as a faint, yellow-hued point of light with an apparent visual magnitude of +4.97. It is drifting further away with a heliocentric radial velocity of +4.4 km/s and has a high proper motion, traversing the celestial sphere at the rate of 0.621 arc seconds per annum.

<span class="mw-page-title-main">HD 12661</span> Star in the constellation Aries

HD 12661 is a G-type main sequence star in the northern constellation of Aries. The star is slightly larger and more massive than the Sun, with an estimated age of seven billion years. It has two known extrasolar planets.

HD 74156 is a yellow dwarf star in the constellation of Hydra, 187 light years from the Solar System. It is known to be orbited by two giant planets.

<span class="mw-page-title-main">HD 187123</span> Star in the constellation Cygnus

HD 187123 is a single, yellow-hued star with two exoplanetary companions in the northern constellation of Cygnus. It has an apparent visual magnitude of 7.83, making it an 8th magnitude star that is too faint to be visible with the naked eye. However, it should be easy target with binoculars or small telescope. The system is located at a distance of 150 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −17 km/s.

HD 28185 is a single yellow dwarf star similar to the Sun, located 128 light-years away from Earth in the constellation Eridanus. The designation HD 28185 refers to its entry in the Henry Draper catalogue. The star is known to possess two long-period extrasolar planets.

HD 38529 is a binary star approximately 138 light-years away in the constellation of Orion.

<span class="mw-page-title-main">HD 108874</span> Star in the constellation Coma Berenices

HD 108874 is a star with a pair of orbiting exoplanets in the northern constellation of Coma Berenices. It is located 194.5 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −30 km/s. The absolute magnitude of this star is 4.79, but at that distance the star has an apparent visual magnitude of 8.76, making it too faint to be visible to the naked eye. HD 108874 has a relatively large proper motion, traversing the celestial sphere at an angular rate of 0.157″ yr−1.

HD 1237 is a binary star system approximately 57 light-years away in the constellation of Hydrus.

109 Piscium is a yellow hued G-type main-sequence star located about 108 light-years away in the zodiac constellation of Pisces. It is near the lower limit of visibility to the naked eye with an apparent visual magnitude of 6.27. The star is moving closer to the Earth with a heliocentric radial velocity of −45.5 km/s. It has one known exoplanet.

HD 217107 b is an extrasolar planet approximately 65 light-years away from Earth in the constellation of Pisces. The planet was discovered orbiting the star HD 217107 approximately every seven days, classifying the planet as a hot Jupiter. Because of the planet's somewhat eccentric orbit, scientists were able to confirm another planet within the system.

<span class="mw-page-title-main">HD 217107 c</span> Extrasolar planet in the constellation Pisces

HD 217107 c is an extrasolar planet approximately 64 light-years away from Earth in the constellation of Pisces. The planet was the second planet to be discovered orbiting the star HD 217107. HD 217107 c's existence was hypothesized in 1998 due to the eccentricity of the inner planet's orbit and confirmed in 2005 when radial velocity studies of the star indicated another, more distant and massive companion orbiting the star. The planet has an eccentric orbit lasting on order of a decade.

HD 11964 is a binary star system located 110 light-years away from the Sun in the equatorial constellation of Cetus. It is visible in binoculars or a telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 7.51. The system is drifting closer to the Sun with a radial velocity of −9 km/s. Two extrasolar planets have been confirmed to orbit the primary.

HD 17156, named Nushagak by the IAU, is a yellow subgiant star approximately 255 light-years away in the constellation of Cassiopeia. The apparent magnitude is 8.17, which means it is not visible to the naked eye but can be seen with good binoculars. A search for a binary companion star using adaptive optics at the MMT Observatory was negative.

HD 114762 b is a small red dwarf star, in the HD 114762 system, formerly thought to be a massive gaseous extrasolar planet, approximately 126 light-years (38.6 pc) away in the constellation of Coma Berenices. This optically undetected companion to the late F-type main-sequence star HD 114762 was discovered in 1989 by Latham, et al., and confirmed in an October 1991 paper by Cochran, et al. It was thought to be the first discovered exoplanet

HD 5319 is an 8th magnitude star approximately 319 light years away in the constellation Cetus. It is a subgiant star of spectral type K3, having run out of hydrogen in its core. When it was main-sequence, the spectral type was early F or late A.

HD 183263 is a star with a pair of orbiting exoplanets located in the equatorial constellation of Aquila. It has an apparent visual magnitude of 7.86, which is too faint to be visible to the naked eye. The distance to this system is 178 light years based on parallax measurements, but it is drifting closer with a heliocentric radial velocity of −50 km/s. Judging from its motion through space, this star is predicted to approach to within 32 light-years of the Sun in around 952,000 years. At that distance, it will be faintly visible to the naked eye.

HD 183263 b is an extrasolar planet orbiting the star HD 183263. This planet has a minimum mass of 3.6 times more than Jupiter and takes 625 days to orbit the star. The planet was discovered on January 25, 2005 using multiple Doppler measurements of five nearby FGK main-sequence stars and subgiants obtained during the past 4–6 years at the Keck Observatory in Mauna Kea, Hawaii. These stars, namely, HD 183263, HD 117207, HD 188015, HD 45350, and HD 99492, all exhibit coherent variations in their Doppler shifts consistent with a planet in Keplerian motion, and the results were published in a paper by Geoffrey Marcy et al. Photometric observations were acquired for four of the five host stars with an automatic telescope at Fairborn Observatory. The lack of brightness variations in phase with the radial velocities supports planetary-reflex motion as the cause of the velocity variations. An additional planet in the system was discovered later.

HD 102272 is a star in the equatorial constellation of Leo. With an apparent visual magnitude of 8.69, it is too faint to be visible to the naked eye. The star is located at a distance of approximately 1,140 light years based on parallax measurements, but is drifting closer to the Sun with a radial velocity of −12 km/s. As of 2008, two extrasolar planets are known to orbit the star.

<span class="mw-page-title-main">Magellan Planet Search Program</span> Ground-based search for extrasolar planets

The Magellan Planet Search Program is a ground-based search for extrasolar planets that makes use of the radial velocity method. It began gathering data in December 2002 using the MIKE echelle spectrograph mounted on the 6.5m Magellan II "Clay" telescope located within the Las Campanas Observatory in Chile. In 2010, the program began using the newly commissioned Planet Finder Spectrograph (PFS), an instrument purpose-built for precise radial velocity measurement.

<span class="mw-page-title-main">Kepler-25</span> Yellow-white hued star in the constellation Lyra

Kepler-25 is a star in the northern constellation of Lyra. It is slightly larger and more massive than the Sun, with a luminosity 21⁄2 times that of the Sun. With an apparent visual magnitude of 10.6, this star is too faint to be seen with the naked eye.

References

  1. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  2. 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.
  3. 1 2 3 4 5 6 Boyajian, Tabetha S.; et al. (July 2013), "Stellar Diameters and Temperatures. III. Main-sequence A, F, G, and K Stars: Additional High-precision Measurements and Empirical Relations", The Astrophysical Journal, 771 (1): 31, arXiv: 1306.2974 , Bibcode:2013ApJ...771...40B, doi:10.1088/0004-637X/771/1/40, S2CID   14911430, 40. See Table 3.
  4. ↑ "HD 217107". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2018-02-26.
  5. 1 2 Fischer, Debra A.; et al. (1999). "Planetary Companions around Two Solar-Type Stars: HD 195019 and HD 217107". Publications of the Astronomical Society of the Pacific. 111 (755): 50–56. arXiv: astro-ph/9810420 . Bibcode:1999PASP..111...50F. doi:10.1086/316304. S2CID   17980987.
  6. ↑ Fischer, Debra A.; et al. (2002). "Planetary Companions to HD 12661, HD 92788, and HD 38529 and Variations in Keplerian Residuals of Extrasolar Planets". The Astrophysical Journal. 551 (2): 1107–1118. Bibcode:2001ApJ...551.1107F. doi: 10.1086/320224 .
  7. ↑ Vogt, Steven S.; et al. (2005). "Five New Multicomponent Planetary Systems" (PDF). The Astrophysical Journal. 632 (1): 638–658. Bibcode:2005ApJ...632..638V. doi:10.1086/432901. S2CID   16509245.
  8. ↑ Wright, J. T.; et al. (2009). "Ten New and Updated Multi-planet Systems, and a Survey of Exoplanetary Systems". The Astrophysical Journal. 693 (2): 1084–1099. arXiv: 0812.1582 . Bibcode:2009ApJ...693.1084W. doi:10.1088/0004-637X/693/2/1084. S2CID   18169921.
  9. ↑ Feng, Y. Katherina; et al. (2015). "The California Planet Survey IV: A Planet Orbiting the Giant Star HD 145934 and Updates to Seven Systems with Long-period Planets". The Astrophysical Journal. 800 (1). 22. arXiv: 1501.00633 . Bibcode:2015ApJ...800...22F. doi:10.1088/0004-637X/800/1/22. S2CID   56390823.
  10. ↑ Giovinazzi, Mark R.; Blake, Cullen H.; Eastman, Jason D.; Wright, Jason; McCrady, Nate; Wittenmyer, Rob; Johnson, John A.; Plavchan, Peter; Sliski, David H.; Wilson, Maurice L.; Johnson, Samson A.; Horner, Jonathan; Kane, Stephen R.; Houghton, Audrey; García-Mejía, Juliana; Glaser, Joseph P. (2020), "The HD 217107 planetary system: Twenty years of radial velocity measurements", Astronomische Nachrichten, 341 (9): 870–878, arXiv: 2009.12356 , Bibcode:2020AN....341..870G, doi:10.1002/asna.202013830, S2CID   221949076
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.