Kepler-4

Last updated
Kepler-4
Observation data
Epoch J2000       Equinox J2000
Constellation Draco [1]
Right ascension 19h 2m 27.6980s [2]
Declination +50° 8′ 08.704″ [2]
Apparent magnitude  (V)12.7 [3]
Characteristics
Spectral type G0 [4]
Astrometry
Proper motion (μ)RA: 6.127(12)  mas/yr [2]
Dec.: 4.642(13)  mas/yr [2]
Parallax (π)2.0055 ± 0.0103  mas [2]
Distance 1,626 ± 8  ly
(499 ± 3  pc)
Details
Mass 1.117+0.021
−0.029 [5]   M☉
Radius 1.555±0.012 [5]   R☉
Luminosity 2.505+0.142
−0.124 [5]   L☉
Surface gravity (log g)4.102+0.005
−0.004 [5]   cgs
Temperature 5781±76 [6]   K
Metallicity [Fe/H]0.09±0.10 [6]   dex
Age 6.71+0.77
−0.67 [5]   Gyr
Other designations
KOI-7, KIC  11853905, GSC  03549-02067, 2MASS J19022767+5008087 [7]
Database references
SIMBAD data
KIC data

Kepler-4 is a sunlike star located about 1626 light-years away in the constellation Draco. It is in the field of view of the Kepler Mission, a NASA operation purposed with finding Earth-like planets. Kepler-4b, a Neptune-sized planet that orbits extremely close to its star, was discovered in its orbit and made public by the Kepler team on January 4, 2010. Kepler-4b was the first discovery by the Kepler satellite, and its confirmation helped to demonstrate the spacecraft's effectiveness.

Contents

Nomenclature and history

Kepler-4 is named for the Kepler spacecraft, a NASA telescope tasked with finding Earth-like planets that transit their stars as seen from Earth. [8] As the previous three planets that Kepler confirmed had already been confirmed by others, Kepler-4 and its planet were the first to be discovered by the Kepler team. [9] The star and its system were announced in Washington, D.C. at the 215th meeting of the American Astronomical Society on January 4, 2010, along with Kepler-5, Kepler-6, Kepler-7, and Kepler-8. Of the presented planets, Kepler-4b was the smallest, around the size of planet Neptune. [10] The discovery of Kepler-4b and the other planets presented at the AAS meeting helped to confirm that the Kepler spacecraft was indeed functional. [11]

The Harlan J. Smith Telescope at McDonald Observatory in Fort Davis, Texas was used by astronomers from the University of Texas at Austin to follow up on Kepler's discoveries and confirm them. [12] Telescopes in Hawaii, California, Arizona, and the Canary Islands were also used to confirm the findings. [11]

Characteristics

A picture showing the relative sizes of the first five planets discovered by Kepler. Kepler-4b is the smallest of the five, highlighted in purple. Kepler first five exoplanet size.jpg
A picture showing the relative sizes of the first five planets discovered by Kepler. Kepler-4b is the smallest of the five, highlighted in purple.

Kepler-4 is a G0-type star, which is similar to the Sun, except slightly brighter. The star is 1.117 Msun and 1.555 Rsun, or 111% the mass of and 155% the radius of the Sun. [5] With a metallicity of .09 (± 0.10) [Fe/H], Kepler-4 is more metal-rich than the Sun, a figure that is important in that metal-rich stars tend to have orbiting planets more often than metal-poor stars. Kepler-4 is also about 6.7 billion years old. [5] In comparison, the Sun is 4.6 billion years old. [13] In addition, Kepler-4 has an effective temperature of 5781 (± 76) K, [6] which is almost identical, within the errors, to that of the Sun, which is 5778 K. [14]

As seen from Earth, Kepler-4 has an apparent magnitude of 12.7. It is, as a result, not visible with the naked eye. [3]

Planetary system

Kepler-4b's discovery was announced on January 4, 2010. It is the size of planet Neptune, at 0.077 MJ (7% the mass of Jupiter) and 0.357 RJ (36% the radius of Jupiter). The planet orbits its star every 3.213 days at 0.045 AU from the star. [4] This distance compares to planet Mercury, which is 0.39 AU from the Sun. [15] Kepler-4's eccentricity was assumed to be 0, however a subsequent independent reanalysis of the discovery data found a value of 0.25 ± 0.12. [16] Likewise, the temperature of the planet is assumed to be 1650 K, far hotter than Jupiter's, which is assumed to be 124 K (not considering its internal heat and atmosphere). [4]

A search for transit-timing variations in all 17 quarters of Kepler data did not detect any evidence of additional planets. [17]

The Kepler-4 planetary system [4] [16]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b 0.077±0.012  MJ 0.0456±0.00093.21346±0.000220.25±0.1289.76+0.24
−2.05 ° 		0.357±0.019  RJ
Kepler-4 System. Kepler-4 System.png
Kepler-4 System.

See also

Related Research Articles

<span class="mw-page-title-main">Methods of detecting exoplanets</span>

Any planet is an extremely faint light source compared to its parent star. For example, a star like the Sun is about a billion times as bright as the reflected light from any of the planets orbiting it. In addition to the intrinsic difficulty of detecting such a faint light source, the light from the parent star causes a glare that washes it out. For those reasons, very few of the exoplanets reported as of January 2024 have been observed directly, with even fewer being resolved from their host star.

<span class="mw-page-title-main">Super-Earth</span> Type of exoplanet

A Super-Earth or super-terran or super-tellurian is a type of exoplanet with a mass higher than Earth, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17.1 times Earth's, respectively. The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or habitability. The alternative term "gas dwarfs" may be more accurate for those at the higher end of the mass scale, although "mini-Neptunes" is a more common term.

<span class="mw-page-title-main">HAT-P-11b</span> Super Neptune orbiting HAT-P-11

HAT-P-11b is an extrasolar planet orbiting the star HAT-P-11. It was discovered by the HATNet Project team in 2009 using the transit method, and submitted for publication on 2 January 2009.

<span class="mw-page-title-main">Kepler-4b</span> Extrasolar planet in the constellation Draco

Kepler-4b, initially known as KOI 7.01, is an extrasolar planet first detected as a transit by the Kepler spacecraft. Its radius and mass are similar to that of Neptune; however, due to its proximity to its host star, it is substantially hotter than any planet in the Solar System. The planet's discovery was announced on January 4, 2010, in Washington, D.C., along with four other planets that were initially detected by the Kepler spacecraft and subsequently confirmed by telescopes at the W.M. Keck Observatory.

<span class="mw-page-title-main">Kepler-8b</span> Extrasolar planet

Kepler-8b is the fifth of the first five exoplanets discovered by NASA's Kepler spacecraft, which aims to discover planets in a region of the sky between the constellations Lyra and Cygnus that transit their host stars. The planet is the hottest of the five. Kepler-8b was the only planet discovered in Kepler-8's orbit, and is larger than Jupiter. It orbits its host star every 3.5 days. The planet also demonstrates the Rossiter–McLaughlin effect, where the planet's orbit affects the redshifting of the spectrum of the host star. Kepler-8b was announced to the public on January 4, 2010 at a conference in Washington, D.C. after radial velocity measurements conducted at the W.M. Keck Observatory confirmed its detection by Kepler.

<span class="mw-page-title-main">Kepler-10</span> Sunlike star in the constellation Draco

Kepler-10, formerly known as KOI-72, is a Sun-like star in the constellation of Draco that lies 607 light-years from Earth. Kepler-10 was targeted by NASA's Kepler space telescope, as it was seen as the first star identified by the Kepler mission that could be a possible host to a small, transiting exoplanet. The star is slightly less massive, slightly larger, and slightly cooler than the Sun; at an estimated 11.9 billion years in age, Kepler-10 is 2.3 times the age of the Sun.

HD 97658 is a star with an exoplanetary companion in the equatorial constellation of Leo. The star is too dim to be seen with the naked eye, having an apparent visual magnitude of 7.76. It is located at a distance of 70 light years based on parallax, but is slowly drifting closer with a radial velocity of −1.6 km/s.

Kepler-47 is a binary star system in the constellation Cygnus located about 3,420 light-years away from Earth. The stars have three exoplanets, all of which orbit both stars at the same time, making this a circumbinary system. The first two planets announced are designated Kepler-47b, and Kepler-47c, and the third, later discovery is Kepler-47d. Kepler-47 is the first circumbinary multi-planet system discovered by the Kepler mission. The outermost of the planets is a gas giant orbiting within the habitable zone of the stars. Because most stars are binary, the discovery that multi-planet systems can form in such a system has impacted previous theories of planetary formation.

<span class="mw-page-title-main">Kepler-37</span> G-type main-sequence star in the constellation Lyra

Kepler-37, also known as UGA-1785, is a G-type main-sequence star located in the constellation Lyra 209 light-years from Earth. It is host to exoplanets Kepler-37b, Kepler-37c, Kepler-37d and possibly Kepler-37e, all of which orbit very close to it. Kepler-37 has a mass about 80.3 percent of the Sun's and a radius about 77 percent as large. It has a temperature similar to that of the Sun, but a bit cooler at 5,357 K. It has about half the metallicity of the Sun. With an age of roughly 6 billion years, it is slightly older than the Sun, but is still a main-sequence star. Until January 2015, Kepler-37 was the smallest star to be measured via asteroseismology.

<span class="mw-page-title-main">Kepler-62f</span> Super-Earth orbiting Kepler-62

Kepler-62f is a super-Earth exoplanet orbiting within the habitable zone of the star Kepler-62, the outermost of five such planets discovered around the star by NASA's Kepler space telescope. It is located about 982 light-years from Earth in the constellation of Lyra.

<span class="mw-page-title-main">Kepler-69</span> Star in the constellation Cygnus

Kepler-69 is a G-type main-sequence star similar to the Sun in the constellation Cygnus, located about 2,390 ly (730 pc) from Earth. On April 18, 2013 it was announced that the star has two planets. Although initial estimates indicated that the terrestrial planet Kepler-69c might be within the star's habitable zone, further analysis showed that the planet very likely is interior to the habitable zone and is far more analogous to Venus than to Earth and thus completely inhospitable.

<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.

<span class="mw-page-title-main">Kepler-90g</span> Super-puff exoplanet in the constellation Draco

Kepler-90g is a super-puff exoplanet orbiting the early G-type main sequence star Kepler-90, one of eight planets around this star discovered using NASA's Kepler space telescope. It is located about 2,840 light-years (870 pc) from Earth, in the constellation Draco. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. It orbits its parent star about every 210.5 days at a distance of 0.71 astronomical units.

Kepler-61 is a K-type main-sequence star approximately 1,100 light years from Earth in the constellation Cygnus. It is located within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission used to detect planets that may be transiting their stars. On April 24, 2013 it was announced that the star has an extrasolar planet orbiting in the inner edge of the habitable zone, named Kepler-61b.

<span class="mw-page-title-main">Kepler-438b</span> Super-Earth orbiting Kepler-438

Kepler-438b is a confirmed near-Earth-sized exoplanet. It is likely rocky. It orbits on the inner edge of the habitable zone of a red dwarf, Kepler-438, about 460.2 light-years from Earth in the constellation Lyra. It receives 1.4 times our solar flux. The planet was discovered by NASA's Kepler spacecraft using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. NASA announced the confirmation of the exoplanet on 6 January 2015.

<span class="mw-page-title-main">Kepler-442b</span> Super-Earth orbiting Kepler-442

Kepler-442b is a confirmed near-Earth-sized exoplanet, likely rocky, orbiting within the habitable zone of the K-type main-sequence star Kepler-442, about 1,196 light-years (367 pc) from Earth in the constellation of Lyra.

<span class="mw-page-title-main">KOI-256</span> Double star in the constellation Cygnus

KOI-256 is a double star located in the constellation Cygnus approximately 575 light-years (176 pc) from Earth. While observations by the Kepler spacecraft suggested the system contained a gas giant exoplanet orbiting a red dwarf, later studies determined that KOI-256 was a binary system composed of the red dwarf orbiting a white dwarf.

Kepler-1229 is a red dwarf star located about 875 light-years (268 pc) away from the Earth in the constellation of Cygnus. It is known to host a super-Earth exoplanet within its habitable zone, Kepler-1229b, which was discovered in 2016.

Kepler-1625 is a 14th-magnitude solar-mass star located in the constellation of Cygnus approximately 7,200 light-years away. Its mass is within 5% of that of the Sun, but its radius is approximately 70% larger reflecting its more evolved state. A candidate gas giant exoplanet was detected by the Kepler Mission around the star in 2015, which was later validated as a real planet to >99% confidence in 2016. In 2018, the Hunt for Exomoons with Kepler project reported evidence for a Neptune-sized exomoon around this planet, based on observations from NASA’s Kepler mission and the Hubble Space Telescope. Subsequently, the evidence for and reality of this exomoon candidate has been subject to debate.

Kepler-13 or KOI-13 is a stellar triple star system consisting of Kepler-13A, around which an orbiting hot Jupiter exoplanet was discovered with the Kepler space telescope in 2011, and Kepler-13B a common proper motion companion star which has an additional star orbiting it.

References

  1. ↑ Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode: 1987PASP...99..695R . doi: 10.1086/132034 . Vizier query form
  2. 1 2 3 4 5 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.
  3. 1 2 Jean Schneider (2010). "Planet Kepler-4 b". Extrasolar Planets Encyclopaedia . Retrieved 5 August 2012.
  4. 1 2 3 4 Borucki, William J.; et al. (2010). "Kepler-4b: A Hot Neptune-like Planet of a G0 Star Near Main-sequence Turnoff". The Astrophysical Journal Letters. 713 (2): L126–L130. arXiv: 1001.0604 . Bibcode: 2010ApJ...713L.126B . doi: 10.1088/2041-8205/713/2/L126 .
  5. 1 2 3 4 5 6 7 Silva Aguirre, V.; et al. (2015). "Ages and fundamental properties of Kepler exoplanet host stars from asteroseismology". Monthly Notices of the Royal Astronomical Society. 452 (2): 2127–2148. arXiv: 1504.07992 . Bibcode: 2015MNRAS.452.2127S . doi: 10.1093/mnras/stv1388 .
  6. 1 2 3 Huber, Daniel; et al. (2013). "Fundamental Properties of Kepler Planet-candidate Host Stars using Asteroseismology". The Astrophysical Journal. 767 (2). 127. arXiv: 1302.2624 . Bibcode: 2013ApJ...767..127H . doi: 10.1088/0004-637X/767/2/127 .
  7. ↑ "Kepler-4". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2018-06-03.
  8. ↑ "Mission overview". Kepler and K2. NASA. 13 April 2015. Retrieved 2 December 2017.
  9. ↑ "Summary Table of Kepler Discoveries". NASA. 2010-08-27. Archived from the original on 2010-05-27. Retrieved 2010-10-16.
  10. ↑ Rich Talcott (5 January 2010). "215th AAS meeting update: Kepler discoveries the talk of the town". Astronomy.com. Astronomy magazine. Retrieved 24 February 2011.
  11. 1 2 "NASA's Kepler Space Telescope Discovers Five Exoplanets" (Press release). Caltech: Jet Propulsion Laboratory. 2010-01-04. Retrieved 2024-12-19.
  12. ↑ "Texas Astronomers Aid Kepler Mission's Discovery of New Planets". UT News. University of Texas at Austin. 4 January 2010. Retrieved 7 August 2020.
  13. ↑ Fraser Cain (16 September 2008). "How Old is the Sun?". Universe Today. Retrieved 25 February 2011.
  14. ↑ David Williams (1 September 2004). "Sun Fact Sheet". Goddard Space Flight Center . NASA . Retrieved 25 February 2011.
  15. ↑ David Williams (17 November 2010). "Mercury Fact Sheet". Goddard Space Flight Center . NASA . Retrieved 25 February 2011.
  16. 1 2 Kipping, David; Bakos, Gáspár (2011). "An Independent Analysis of Kepler-4b through Kepler-8b". The Astrophysical Journal. 730 (1). 50. arXiv: 1004.3538 . Bibcode: 2011ApJ...730...50K . doi: 10.1088/0004-637X/730/1/50 .
  17. ↑ Gajdoš, Pavol; Vaňko, Martin; Parimucha, Štefan (2019). "Transit timing variations and linear ephemerides of confirmed Kepler transiting exoplanets". Research in Astronomy and Astrophysics. 19 (3). 041. arXiv: 1809.11104 . Bibcode: 2019RAA....19...41G . doi: 10.1088/1674-4527/19/3/41 . Vizier catalog entry

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