Next-Generation Transit Survey
24°36′57″S 70°23′28″W / 24.61583°S 70.39111°W
The Next-Generation Transit Survey (NGTS) is a ground-based robotic search for
The aim of NGTS is to discover
NGTS is suited to ground-based
Science mission
Ground-based surveys for extrasolar planets such as
By focusing on super-Earth- to Neptune-sized targets orbiting cool, small, but bright stars of K and early-M spectral type, over an area considerably larger than that covered by space missions, NGTS is intended to provide prime targets for further scrutiny by telescopes such as the
In follow-up observations by larger telescopes, powerful means will be available to probe the atmospheric composition of exoplanets discovered by NGTS. For example, during secondary eclipse, when the star occults the planet, a comparison between the in-transit and out-of-transit flux allows computation of a difference spectrum representing the thermal emission of the planet.[8] Calculation of the transmission spectrum of the planet's atmosphere can be obtained by measuring the small spectral changes in the spectrum of the star that arise during the planet's transit. This technique requires an extremely high signal-to-noise ratio, and has thus far been successfully applied to only a few planets orbiting small, nearby, relatively bright stars, such as HD 189733 b and GJ 1214 b. NGTS is intended to greatly increase the number of planets that area analyzable using such techniques.[8] Simulations of expected NGTS performance reveal the potential of discovering approximately 231 Neptune- and 39 super-Earth-sized planets amenable to detailed spectrographic analysis by the VLT, compared to only 21 Neptune- and 1 super-Earth-sized planets from the Kepler data.[4]
Instrument
Development
The scientific goals of the NGTS require being able to detect transits with a precision of 1 mmag at 13th magnitude. Although at ground level this level of accuracy was routinely achievable in narrow-field observations of individual objects, it was unprecedented for a wide-field survey.[4] To achieve this goal, the designers of the NGTS instruments drew upon an extensive hardware and software heritage from the WASP project, in addition to developing many refinements in prototype systems operating on La Palma during 2009 and 2010, and at the Geneva Observatory from 2012 to 2014.[6]
Telescope array
NGTS employs an automated array of twelve 20-centimeter f/2.8 telescopes on independent equatorial mounts and operating at orange to near-infrared wavelengths (600–900 nm). It is located at the European Southern Observatory's Paranal Observatory in Chile, a location noted for low water-vapor and excellent photometric conditions.
Combined search
The NGTS telescope project cooperates closely with ESO's large telescopes. ESO facilities available for follow-up studies include the
Partnership
Although located at Paranal Observatory, NGTS is not in fact operated by ESO, but by a consortium of seven academic institutions from Chile, Germany, Switzerland, and the United Kingdom:[3]
- Institute for Planetary Research
- Geneva Observatory
- Queen's University Belfast
- University of Cambridge
- University of Chile
- University of Leicester
- University of Warwick
Results
- On 31 October 2017, the discovery of extrasolar planet orbiting NGTS-1, an M-dwarf star, about half the mass and radius of the Sun, every 2.65 days, was reported by the survey team.[10][11][12] Daniel Bayliss, of the University of Warwick, and lead author of the study describing the discovery of NGTS-1b, stated, "The discovery of NGTS-1b was a complete surprise to us—such massive planets were not thought to exist around such small stars – importantly, our challenge now is to find out how common these types of planets are in the Galaxy, and with the new Next-Generation Transit Survey facility we are well-placed to do just that."[12]
- On 3 September 2018, the discovery of NGTS-4b, a sub-Neptune-sized planet transiting a 13th magnitude K-dwarf in a 1.34 day orbit. NGTS-4b has a mass 20.6 ± 3.0 ME and radius 3.18 ± 0.26 R🜨, which places it well within the so-called "Neptunian desert". The mean density of the planet (3.45 ± 0.95 g cm−3) is consistent with a composition of 100% H2O or a rocky core with a volatile envelope.[13]
Discoveries
Planets
This is a list of planets discovered by this survey. This list is incomplete, and requires more information.
Star | Constellation | Right ascension |
Declination | App. mag. |
ly )
|
Spectral type |
Planet | Mass (MJ) |
Radius (RJ) |
Orbital period (d) |
) | Orbital
eccentricity |
Inclination )
(° |
Discovery year |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
NGTS-1 | Columba | 05h 30m 51.41s | −36° 37′ 51.53″ | 15.67 | 711 | M0.5 V | NGTS-1b | 0.812 | 1.33 | 2.65 | 0.023 | 0.016 | 85.27 | 2017[10] |
NGTS-2 | Centaurus | 14h 20m 29.46s | −31° 12′ 07.45″ | 10.79 | 1,162 | F5 V | NGTS-2b | 0.74 | 1.595 | 4.51 | 0.04 | 0 | 83.45 | 2018[14] |
NGTS-3 | Columba | 06h 17m 46.74s | −35° 42′ 22.91″ | 14.669 | 2,426 | G6 V + K1 V | NGTS-3Ab | 2.38 | 1.48 | 1.68 | 0.02 | 0? | 89.56 | 2018[15] |
NGTS-4 | Columba | 05h 58m 23.75s | −30° 48′ 42.36″ | 13.12 | 922 | K2 V | NGTS-4b
|
0.06 | 0.25 | 1.34 | 0.02 | 0 | 82.5 ± 5.8 | 2018[13] |
NGTS-5 | Virgo | 14h 44m 13.97s | 05° 36′ 19.42″ | 13.77 | 1,009 | K2 V + M2 V | NGTS-5Ab | 0.229 | 1.136 | 3.36 | 0.04 | 0? | 86.6 ± 0.2 | 2019[16] |
NGTS-6 | Caelum | 05h 03m 10.90s | −30° 23′ 57.72″ | 14.12 | 1,014 | K4 V | NGTS-6Ab | 1.339 ± 0.028 | 1.326 | 0.882 | 0.01 | 0 | 78.231 | 2019[17] |
NGTS-8 | Capricornus | 21h 55m 54.22s | −14° 04′ 6.38″ | 13.68 | 1,399 | K0 V | NGTS-8b | 0.93 ± 0.01 | 1.09 ± 0.03 | 2.50 | 0.035 | 0.01 | 86.9 ± 0.5 | 2019[18] |
NGTS-9 | Hydra | 09h 27m 40.95s | −19° 20′ 51.53″ | 12.80 | 1,986 | F8 V | NGTS-9b | 2.90 ± 0.17 | 1.07 ± 0.06 | 4.435 | 0.058 | 0.06 | 84.1 ± 0.4 | 2019[18] |
NGTS-10 | Lepus | 06h 07m 29.31s | −25° 35′ 40.61″ | 14.34 | 1,059 | K5 V + K5 V | NGTS-10Ab | 2.162 | 1.205 | 0.77 | 0.0143 | 0? | ? | 2019[19] |
NGTS-11 | Cetus | 01h 34m 05.14s | −14° 25′ 09.16″ | 12.46 | 621 | K2 V | NGTS-11b | 0.344 | 0.817 | 35.455 | 0.201 | 0.11 | ? | 2020[20] |
NGTS-12 | Centaurus | 11h 44m 59.99s | −35° 48′ 26.03″ | 12.38 | 1,456 | G4 V | NGTS-12b | 0.208 | 1.048 | 7.53 | 0.0757 | 0? | 88.90 ± 0.76 | 2020[21] |
NGTS-13 | Centaurus | 11h 44m 57.68s | −38° 08′ 22.96″ | 12.70 | 2,151 | G2 IV | NGTS-13b | 4.84 | 1.142 | 4.119 | 0.0549 | 0.086 | 88.7 | 2021[22] |
NGTS-14 | Grus | 21h 54m 04.23s | −38° 22′ 38.79″ | 13.24 | 1,060 | K1 V + M3 V | NGTS-14Ab | 0.092 | 0.44 | 3.536 | 0.0403 | 0? | 86.7 | 2021[23] |
NGTS-15 | Eridanus | 04h 53m 25.27s | −32° 48′ 01.25″ | 14.67 | 2,626 | G6 V | NGTS-15b | 0.751 | 1.10 ± 0.10 | 3.276 | 0.0441 | 0 | ? | 2021[24] |
NGTS-16 | Fornax | 03h 53m 03.34s | −30° 48′ 16.71″ | 14.36 | 3,008 | G7 V | NGTS-16b | 0.667 | 1.30 | 4.845 | 0.0523 | 0 | ? | 2021[24] |
NGTS-17 | Caelum | 04h 51m 36.14s | −34° 13′ 34.18″ | 14.31 | 3,366 | G4 V | NGTS-17b | 0.764 | 1.24 ± 0.11 | 3.242 | 0.0391 | 0 | ? | 2021[24] |
NGTS-18 | Hydra | 12h 02m 11.09s | −35° 32′ 54.99″ | 14.54 | 3,689 | G5 V | NGTS-18b | 0.409 | 1.21 ± 0.18 | 3.051 | 0.0448 | 0 | ? | 2021[24] |
NGTS-20 | Eridanus | 46h 17m 33.43s | −21° 56′ 01.1″ | 11.79 | 1,248 | G1 IV | NGTS-20b | 2.98 | 1.07±0.04 | 54.189 | 0.313 | 0.432 ± 0.023 | 88.4 ± 0.6 | 2022[25] |
NGTS-21 | Sculptor | 20h 45m 01.99s | −35° 25′ 40.23″ | 14.82 | 2,090 | K3 V | NGTS-21b | 2.36 ± 0.21 | 1.33 ± 0.03 | 1.543 | 0.0236 | 0 | 83.85 ± 0.44 | 2022[26] |
HATS-54 (NGTS-22)[note 1] | Phoenix | 13h 22m 32.4s | −44° 41′ 20.0″ | 13.914 | 2,348 | G6 V | HATS-54b (NGTS-22b) | 1.015 ± 0.024 | 0.753 ± 0.057 | 2.544 | 0.0370 | 0 | 83.67 ± 0.34 | 2018[27][28] |
NGTS-23 | Horologium | 04h 41m 43.6s | −40° 02′ 41.0″ | 14.010 | 3,232 | F9 V | NGTS-23b | 0.613 ± 0.097 | 1.267 ± 0.030 | 4.076 | 0.0504 | 0 | 89.12 | 2022[28] |
NGTS-24 | Antlia | 11h 14m 15.3s | −37° 54′ 36.5″ | 13.192 | 2,364 | G2 IV | NGTS-24b | 0.520 | 1.214 | 3.467 | 0.0479 | 0 | 82.61 | 2022[28] |
NGTS-25 | Sagittarius | 20h 29m 40.3s | −39° 01′ 55.5″ | 14.266 | 1,686 | K0 V | NGTS-25b | 0.639 | 1.023 | 2.823 | 0.0388 | 0 | 89.34 | 2022[28] |
Brown dwarfs
In addition, the survey has discovered two brown dwarfs.
Star | Constellation | Right ascension |
Declination | App. mag. |
ly )
|
Spectral type |
Planet | Mass (MJ) |
Radius (RJ) |
Orbital period (d) |
) | Orbital
eccentricity |
Inclination )
(° |
Discovery year |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
NGTS-7 A | Sculptor | 23h 30m 05.26s | −38° 58′ 11.70″ | 14.34 | 449 | M3/4 V + M3/4 V | NGTS-7Ab | 75.5 | 1.349 | 16.22 h | 0.0139 | 0? | 88.43520 | 2019[29] |
NGTS-19 | Libra | 15h 16m 31.6s | −25° 42′ 17.24″ | 14.12 | 1,223 | K3 V | NGTS-19b | 69.5 | 1.034 | 17.84 | 0.1296 | 0.3767 | 88.72 | 2021[30] |
See also
- List of extrasolar planets
Other exoplanet search projects
- HATNet Project (HAT)
- Miniature Exoplanet Radial Velocity Array (MINERVA)
- Kilodegree Extremely Little Telescope (KELT)
- Trans-Atlantic Exoplanet Survey (TrES)
- Wide Angle Search for Planets (WASP and SuperWASP)
- XO Telescope
- Microlensing Observations in Astrophysics (MOA)
- Optical Gravitational Lensing Experiment (OGLE)
- Anglo-Australian Planet Search (AAPS)
- Cool Companions on Ultrawide Orbits (COCONUTS)
- Transiting Planets and Planetesimals Small Telescope(TRAPPIST)
- Search for Habitable Planets Eclipsing Ultra-cool Stars (SPECULOOS)
Notes
- HATNet, updated parameters by NGTS.
References
- ^ hdl:1885/204054.
- ^ "New Exoplanet-hunting Telescopes on Paranal". European Southern Observatory. 14 January 2015. Retrieved 4 September 2015.
- ^ a b c d "About NGTS". Next Generation Transit Survey. Archived from the original on 31 May 2015. Retrieved 22 May 2015.
- ^ S2CID 51743906.
- ^ "Searching for Super-Earths" (PDF). Queen's University. 2014. Retrieved 2 September 2015.
- ^ a b McCormac, J.; Pollacco, D.; The NGTS Consortium. "The Next Generation Transit Survey Prototyping Phase" (PDF). Retrieved 22 May 2015.
- ^ Daniel Clery (14 January 2015). "New exoplanet hunter opens its eyes to search for super-Earths". Science.
- ^ a b "NGTS Science Programme". Next Generation Transit Survey. Archived from the original on 16 December 2017. Retrieved 22 May 2015.
- ^ "SPHERE - Spectro-Polarimetric High-contrast Exoplanet REsearch". European Southern Observatory. Retrieved 23 May 2015.
- ^ S2CID 39357327.
- ^ Lewin, Sarah (31 October 2017). "Monster Planet, Tiny Star: Record-Breaking Duo Puzzles Astronomers". Space.com. Retrieved 1 November 2017.
- ^ a b Staff (31 October 2017). "'Monster' planet discovery challenges formation theory". Phys.org. Retrieved 1 November 2017.
- ^ .
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- S2CID 146809360.
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- S2CID 220845943.
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- S2CID 231582818.
- S2CID 230524042.
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- S2CID 250408027.
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- S2CID 119409621.
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External links
- Official website
- Media related to Next-Generation Transit Survey at Wikimedia Commons
- The Next Generation Transit Survey Becomes Operational at Paranal, ESO archive, The Messenger 165 – September 2016