Kepler-452b

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Kepler-452b
Kepler-452b artist concept.jpg
Artist's impression of Kepler-452b (center), depicted here as a rocky planet in the habitable zone with extensive cloud cover. The actual appearance and composition of the exoplanet is unknown.
Discovery
Discovered by Kepler Science team
Discovery site Kepler
Discovery date23 July 2015 (announced)
Transit
Designations
KOI-7016.01
Orbital characteristics
1.046+0.019
−0.015 [1] AU
384.843+0.007
−0.012 [1] d
Inclination 89.806+0.134
−0.049
Star Kepler-452
Physical characteristics
1.5+0.32
−0.22 [1] R🜨
Mass 5 ± 2 [2] ME
1.9+1.5
−1.0 (est.) g [3]
Temperature Teq: 265K+15
−13 (265 K (−8 °C; 17 °F)) [1]

    Kepler-452b (sometimes quoted to be an Earth 2.0 or Earth's Cousin [4] [5] based on its characteristics; also known by its Kepler object of interest designation KOI-7016.01) is a candidate [6] [7] super-Earth exoplanet orbiting within the inner edge of the habitable zone of the sun-like star Kepler-452 and is the only planet in the system discovered by the Kepler space telescope. It is located about 1,800 light-years (550 pc) [8] from Earth in the constellation of Cygnus.

    Contents

    Kepler-452b orbits its star at a distance of 1.04 AU (156 million km; 97 million mi) from its host star (nearly the same distance as Earth from the Sun), with an orbital period of roughly 385 days, has a mass at least five times that of Earth, and has a radius of around 1.5 times that of Earth. It is the first potentially rocky super-Earth [9] planet discovered orbiting within the habitable zone of a very Sun-like star. [10] However, it is unknown if it is entirely habitable, as it is receiving slightly more energy from its star than Earth and could be subjected to a runaway greenhouse effect.

    The Kepler space telescope identified the exoplanet, and its discovery was announced by NASA on 23 July 2015. [11] The planet is about 1,800 light-years (550 pc) away from the Solar System. At the speed of the New Horizons spacecraft, at about 59,000 km/h (16,000 m/s; 37,000 mph), it would take approximately 30 million years to get there. [12]

    Physical characteristics

    Mass, radius and temperature

    Size comparison between Kepler-452b (right) and Earth (left), along with the similarities of their parent stars. Kepler-452b and Earth Size.jpg
    Size comparison between Kepler-452b (right) and Earth (left), along with the similarities of their parent stars.

    Kepler-452b has a probable mass five times that of Earth, and its surface gravity is nearly twice as much as Earth's, though calculations of mass for exoplanets are only rough estimates. [3] If it is a terrestrial planet, it is most likely a super-Earth with many active volcanoes due to its higher mass and density. The clouds on the planet would be thick and misty, covering much of the surface as viewed from space.

    The planet takes 385 Earth days to orbit its star. [13] Its radius is 50% larger than Earth's, and lies within the conservative habitable zone of its parent star. [3] [14] It has an equilibrium temperature of 265 K (−8 °C; 17 °F), a little warmer than Earth.

    Host star

    The host star, Kepler-452, is a G-type and has about the same mass as the sun, only 3.7% more massive and 11% larger. It has a surface temperature of 5757 K, nearly the same as the Sun, which has a surface temperature of 5778 K. [15] The star's age is estimated to be about 6 billion years old, about 1.5 billion years older than the Sun, which is estimated to have existed for 4.6 billion years. Kepler-452b has been in Kepler-452's habitable zone for most of its existence, a duration just over six billion years. [16]

    From the surface of Kepler-452b, its star would look almost identical to the Sun as viewed from the Earth. [17] The star's apparent magnitude, or how bright it appears from Earth's perspective, is 13.426; therefore, it is too dim to be seen with the naked eye.

    Orbit

    Kepler-452b orbits its host star with an orbital period of 385 days and an orbital radius of about 1.04 AU, nearly the same as Earth's (1 AU). Kepler-452b is most likely not tidally locked and has a circular orbit. Its host star, Kepler-452, is about 20% more luminous than the Sun (L = 1.2 L☉).

    Potential habitability

    Comparison of Kepler-452b and related exoplanets with Earth. Kepler452b-Earth-SurfaceTemp-vs-Energy-20150723.gif
    Comparison of Kepler-452b and related exoplanets with Earth.

    It is not known if Kepler-452b is a rocky planet [4] but based on its small radius, Kepler-452b is likely to be rocky. [11] It is not clear if Kepler-452b offers habitable environments. It orbits a G2V-type star, like the Sun, which is 20% more luminous, with nearly the same temperature and mass. [13] However, the star is roughly 6 billion years old, making it 1.5 billion years older than the Sun. At this point in its star's evolution, Kepler-452b is currently receiving 10% more energy from its parent star than Earth is currently receiving from the Sun. [10] If Kepler-452b is a rocky planet, it may be subject to a runaway greenhouse effect similar to that seen on Venus. [18]

    "Delayed" runaway greenhouse effect

    However, due to the planet Kepler-452b being 50 percent bigger in terms of size, it is likely to have an estimated mass of 5 ME, which could allow it to hold on to any oceans it may have for a longer period, preventing Kepler-452b from succumbing to runaway greenhouse effect for another 500 million years. [18] This, in turn, would be accompanied by the carbonate–silicate cycle being "buffered", extending its lifetime due to increased volcanic activity on Kepler-452b. [19] This could allow any potential life on the surface to inhabit the planet for another 500–900 million years before the habitable zone is pushed beyond Kepler-452b's orbit.

    Discovery and follow-up studies

    In 2009, NASA's Kepler space telescope was observing stars on its photometer, the instrument it uses to detect transit events, in which a planet crosses in front of and dims its host star for a brief and roughly regular time. In this last test, Kepler observed 50000 stars in the Kepler Input Catalog, including Kepler-452; the preliminary light curves were sent to the Kepler science team for analysis, who chose obvious planetary companions from the bunch for follow-up by other telescopes. Observations for the potential exoplanet candidates took place between 13 May 2009 and 17 March 2012. Kepler-452b exhibited a transit that occurred roughly every 385 days, and it was eventually concluded that a planetary body was responsible. The discovery was announced by NASA on 23 July 2015. [11]

    At a distance of nearly 1,800 light-years (550 pc), Kepler-452b is too remote for current telescopes or the next generation of planned telescopes to determine its true mass or whether it has an atmosphere. The Kepler space telescope focused on a single small region of the sky but next-generation planet-hunting space telescopes, such as TESS and CHEOPS, will examine nearby stars throughout the sky with follow up studies planned for these closer exoplanets by the James Webb Space Telescope and future large ground-based telescopes to analyze their atmospheres, determine masses, and infer compositions.

    A study in 2018 by Mullally et al. claimed that statistically, Kepler-452b has not been proven to exist and must still be considered a candidate. [6] However, Kepler-452b is still a possible planet and has not been shown to be a false positive. [6]

    SETI targeting

    Scientists with the SETI (Search for Extraterrestrial Intelligence Institute) have already begun targeting Kepler-452b, the first near-Earth-size world found in the habitable zone of a Sun-like star. [20] SETI Institute researchers are using the Allen Telescope Array, a collection of 6-meter (20 feet) telescopes in the Cascade Mountains of California, to scan for radio transmissions from Kepler-452b. As of July 2015, the array has scanned the exoplanet on over 2 billion frequency bands, with no result. The telescopes will continue to scan over a total of 9 billion channels, searching for alien radio analysis. [20]

    Observation and exploration

    Kepler-452b is 1,800 light-years (550 parsecs) from Earth. The fastest current spacecraft, the New Horizons uncrewed probe that passed Pluto in July 2015, travels at just 56,628 km/h (15,730 m/s; 35,187 mph; 0.00037853 AU/h). [5] At that speed, it would take a spacecraft about 26 million years to reach Kepler-452b from Earth, if it were going in that direction. [5]

    Notable Exoplanets – Kepler Space Telescope
    PIA19827-Kepler-SmallPlanets-HabitableZone-20150723.jpg
    Comparison of small planets found by Kepler in the habitable zone of their host stars.

    See also

    Related Research Articles

    <span class="mw-page-title-main">Kepler space telescope</span> NASA space telescope for exoplanetology (2009–2018)

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    <span class="mw-page-title-main">Earth analog</span> Planet with environment similar to Earths

    An Earth analog, also called an Earth twin or second Earth, is a planet or moon with environmental conditions similar to those found on Earth. The term Earth-like planet is also used, but this term may refer to any terrestrial planet.

    <span class="mw-page-title-main">Discoveries of exoplanets</span> Detecting planets located outside the Solar System

    An exoplanet is a planet located outside the Solar System. The first evidence of an exoplanet was noted as early as 1917, but was not recognized as such until 2016; no planet discovery has yet come from that evidence. What turned out to be the first detection of an exoplanet was published among a list of possible candidates in 1988, though not confirmed until 2003. The first confirmed detection came in 1992, with the discovery of terrestrial-mass planets orbiting the pulsar PSR B1257+12. The first confirmation of an exoplanet orbiting a main-sequence star was made in 1995, when a giant planet was found in a four-day orbit around the nearby star 51 Pegasi. Some exoplanets have been imaged directly by telescopes, but the vast majority have been detected through indirect methods, such as the transit method and the radial-velocity method. As of 24 July 2024, there are 7,026 confirmed exoplanets in 4,949 planetary systems, with 1007 systems having more than one planet. This is a list of the most notable discoveries.

    <span class="mw-page-title-main">Kepler-22b</span> Super-Earth exoplanet orbiting Kepler-22

    Kepler-22b is an exoplanet orbiting within the habitable zone of the Sun-like star Kepler-22. It is located about 640 light-years from Earth in the constellation of Cygnus. It was discovered by NASA's Kepler Space Telescope in December 2011 and was the first known transiting planet to orbit within the habitable zone of a Sun-like star, where liquid water could exist on the planet's surface. Kepler-22 is too dim to be seen with the naked eye.

    <span class="mw-page-title-main">Kepler-47c</span> Temperate gas giant in Kepler-47 system

    Kepler-47c is an exoplanet orbiting the binary star system Kepler-47, the outermost of three such planets discovered by NASA's Kepler spacecraft. The system, also involving two other exoplanets, is located about 3,400 light-years away.

    <span class="mw-page-title-main">Kepler-69c</span> Super-Earth orbiting Kepler-69

    Kepler-69c is a confirmed super-Earth exoplanet, likely rocky, orbiting the Sun-like star Kepler-69, the outermore of two such planets discovered by NASA's Kepler spacecraft. It is located about 2,430 light-years from Earth.

    Kepler-37c is an exoplanet discovered by the Kepler space telescope in February 2013. With an orbital period of 21 days, it is located 209 light-years away, in the constellation Lyra.

    <span class="mw-page-title-main">Kepler-62e</span> Habitable-zone super-Earth planet orbiting Kepler-62

    Kepler-62e is a super-Earth exoplanet discovered orbiting within the habitable zone of Kepler-62, the second outermost of five such planets discovered by NASA's Kepler spacecraft. Kepler-62e is located about 990 light-years from Earth in the constellation of Lyra. The exoplanet was found using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. Kepler-62e may be a terrestrial or ocean-covered planet; it lies in the inner part of its host star's habitable zone.

    <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.

    Kepler-61b is a super-Earth exoplanet orbiting within parts of the habitable zone of the K-type main-sequence star Kepler-61. It is located about 1,100 light-years from Earth in the constellation of Cygnus. It was discovered in 2013 using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured, by NASA's Kepler spacecraft.

    <span class="mw-page-title-main">Kepler-90h</span> Exoplanet in the constellation Draco

    Kepler-90h is an exoplanet orbiting within the habitable zone of the early G-type main sequence star Kepler-90, the outermost of eight such planets discovered by NASA's Kepler spacecraft. It is located about 2,840 light-years, 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.

    <span class="mw-page-title-main">Kepler-186f</span> Terrestrial exoplanet orbiting Kepler-186

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

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    <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">Kepler-452</span> G-type main-sequence star in the constellation Cygnus

    Kepler-452 is a G-type main-sequence star located about 1,810 light-years away from Earth in the Cygnus constellation. Although similar in temperature to the Sun, it is 20% brighter, 3.7% more massive and 11% larger. Alongside this, the star is approximately six billion years old and possesses a high metallicity.

    Kepler-419c is a super-Jupiter exoplanet orbiting within the habitable zone of the star Kepler-419, the outermost of two such planets discovered by NASA's Kepler spacecraft. It is located about 3,400 light-years from Earth in the constellation Cygnus. The exoplanet was found by using the transit timing variation method, in which the variations of transit data from an exoplanet are studied to reveal a more distant companion.

    <span class="mw-page-title-main">Kepler-1229b</span> Super-Earth orbiting Kepler-1229

    Kepler-1229b is a confirmed super-Earth exoplanet, likely rocky, orbiting within the habitable zone of the red dwarf Kepler-1229, located about 870 light years from Earth in the constellation of Cygnus. It was discovered in 2016 by the Kepler space telescope. 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.

    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.

    <span class="mw-page-title-main">K2-72e</span> Goldilocks terrestrial exoplanet orbiting K2-72

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    <span class="mw-page-title-main">Habitability of yellow dwarf systems</span> Likelihood of finding extraterrestrial life in yellow dwarf systems

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    References

    1. 1 2 3 4 "NASA Exoplanet Archive – Confirmed Planet Overview – Kepler-452b". NASA Exoplanet Archive . 2009. Archived from the original on 24 July 2015. Retrieved 23 July 2008.
    2. ↑ "NASA's Kepler Mission Discovers Bigger, Older Cousin to Earth". National Aeronautics and Space Administration. 23 July 2015. Archived from the original on 15 August 2015. Retrieved 10 June 2016.
    3. 1 2 3 Feltman, Rachel (23 July 2015). "Scientists discover 12 new potential Earth-like planets". The Washington Post . Archived from the original on 18 July 2020. Retrieved 23 July 2015.
    4. 1 2 Rincon, Paul (23 July 2015). "'Earth 2.0' found in Nasa Kepler telescope haul". BBC News. Archived from the original on 19 July 2020. Retrieved 24 July 2015.
    5. 1 2 3 "Kepler-452b: How long would it take humans to reach 'Earth 2' and could we live there?". 28 July 2015. Archived from the original on 5 May 2016. Retrieved 9 January 2016.
    6. 1 2 3 Mullally, Fergal; Thompson, Susan E.; Coughlin, Jeffrey L.; Burke, Christopher J.; Rowe, Jason F. (May 2018). "Kepler's Earth-like Planets Should Not Be Confirmed without Independent Detection: The Case of Kepler-452b". The Astronomical Journal . 155 (5): 210. arXiv: 1803.11307 . Bibcode:2018AJ....155..210M. doi: 10.3847/1538-3881/aabae3 .
    7. ↑ Burke, Christopher J.; Mullally, F.; Thompson, Susan E.; Coughlin, Jeffrey L.; Rowe, Jason F. (April 2019). "Re-evaluating Small Long-period Confirmed Planets from Kepler". The Astronomical Journal . 157 (4): 143. arXiv: 1901.00506 . Bibcode:2019AJ....157..143B. doi: 10.3847/1538-3881/aafb79 .
    8. ↑ 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 .
    9. ↑ "The Habitable Exoplanets Catalog – Planetary Habitability Laboratory @ UPR Arecibo". upr.edu. Archived from the original on 11 February 2018. Retrieved 23 July 2015.
    10. 1 2 Chou, Felicia; Johnson, Michele (23 July 2015). "NASA's Kepler Mission Discovers Bigger, Older Cousin to Earth" (Press release). NASA. Archived from the original on 7 October 2015. Retrieved 23 July 2015.
    11. 1 2 3 Jenkins, Jon M.; Twicken, Joseph D.; Batalha, Natalie M.; et al. (23 July 2015). "Discovery and Validation of Kepler-452b: A 1.6 R🜨 Super Earth Exoplanet in the Habitable Zone of a G2 Star" (PDF). The Astronomical Journal. 150 (2): 56. arXiv: 1507.06723 . Bibcode:2015AJ....150...56J. doi:10.1088/0004-6256/150/2/56. ISSN   1538-3881. S2CID   26447864. Archived (PDF) from the original on 5 July 2016. Retrieved 24 July 2015.
    12. ↑ "NASA telescope discovers Earth-like planet in star's 'habitable zone". BNO News . 23 July 2015. Archived from the original on 4 March 2016. Retrieved 23 July 2015.
    13. 1 2 Overbye, Dennis (24 July 2015). "Kepler Data Reveals What Might Be Best 'Goldilocks' Planet Yet". The New York Times . Archived from the original on 24 July 2015. Retrieved 23 July 2015.
    14. ↑ Witze, Alexandra (23 July 2015). "NASA spies Earth-sized exoplanet orbiting Sun-like star". Nature. Archived from the original on 23 November 2019. Retrieved 23 July 2015.
    15. ↑ Fraser Cain (15 September 2008). "Temperature of the Sun". Universe Today. Archived from the original on 29 August 2010. Retrieved 19 February 2011.
    16. ↑ Bohan, Elise; Dinwiddie, Robert; Challoner, Jack; Stuart, Colin; Harvey, Derek; Wragg-Sykes, Rebecca; Chrisp, Peter; Hubbard, Ben; Parker, Phillip; et al. (Writers) (February 2016). Big History. Foreword by David Christian (1st American ed.). New York: DK. p. 77. ISBN   978-1-4654-5443-0. OCLC   940282526. Archived from the original on 8 September 2024. Retrieved 18 March 2023.
    17. ↑ NASA Kepler press conference. 23 July 2015.
    18. 1 2 Lugmayr, Luigi (23 July 2015). "Kepler-452b details unveiled". I4U News. Archived from the original on 9 October 2019. Retrieved 23 July 2015.
    19. ↑ "Is Earth's Closest Cousin A Dying Planet?". Gizmodo.com. 30 July 2015. Archived from the original on 19 May 2016. Retrieved 24 May 2016.
    20. 1 2 "SETI Targets Kepler-452b, Earth's 'Cousin,' in Search for Alien Life". Space.com . 31 July 2015. Archived from the original on 20 July 2020. Retrieved 9 January 2016.
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