TY - JOUR
T1 - NGTS-8b and NGTS-9b: two non-inflated hot-Jupiters
AU - Costes, Jean C.
AU - Watson, Christopher A.
AU - Belardi, Claudia
AU - Braker, Ian P.
AU - Burleigh, Matthew R.
AU - Casewell, Sarah L.
AU - Eigmüller, Philipp
AU - Günther, Maximilian N.
AU - Jackman, James A. G.
AU - Nielsen, Louise D.
AU - Soto, Maritza G.
AU - Turner, Oliver
AU - Anderson, David R.
AU - Bayliss, Daniel
AU - Bouchy, François
AU - Briegal, Joshua T.
AU - Bryant, Edward M.
AU - Cabrera, Juan
AU - Chaushev, Alexander
AU - Csizmadia, Szilard
AU - Erikson, Anders
AU - Gill, Samuel
AU - Gillen, Edward
AU - Goad, Michael R.
AU - Hodgkin, Simon
AU - Hooton, Matthew J.
AU - Jenkins, James S.
AU - McCormac, James
AU - Moyano, Maximiliano
AU - Queloz, Didier
AU - Rauer, Heike
AU - Raynard, Liam
AU - Smith, Alexis M. S.
AU - Thompson, Andrew P. G.
AU - Tilbrook, Rosanna H.
AU - Udry, Stephane
AU - Vines, Jose I.
AU - West, Richard G.
AU - Wheatley, Peter J.
PY - 2019/11/20
Y1 - 2019/11/20
N2 - We report the discovery, by the Next Generation Transit Survey (NGTS),
of two hot-Jupiters NGTS-8b and NGTS-9b. These orbit a V = 13.68 K0V
star (Teff = 5241 ± 50 K) with a period of 2.49970
days, and a V = 12.80 F8V star (Teff = 6330 ± 130 K)
in 4.43527 days, respectively. The transits were independently verified
by follow-up photometric observations with the SAAO 1.0-m and Euler
telescopes, and we report on the planetary parameters using HARPS, FEROS
and CORALIE radial velocities. NGTS-8b has a mass, 0.93 ^{+0.04}_{-0.03}
MJ and a radius, 1.09 ± 0.03 RJ similar to
Jupiter, resulting in a density of 0.89 ^{+0.08}_{-0.07} g
cm-3. This is in contrast to NGTS-9b, which has a mass of
2.90 ± 0.17 MJ and a radius of 1.07 ± 0.06
RJ, resulting in a much greater density of
2.93^{+0.53}_{-0.49} g cm-3. Statistically, the planetary
parameters put both objects in the regime where they would be expected
to exhibit larger than predicted radii. However, we find that their
radii are in agreement with predictions by theoretical non-inflated
models.
AB - We report the discovery, by the Next Generation Transit Survey (NGTS),
of two hot-Jupiters NGTS-8b and NGTS-9b. These orbit a V = 13.68 K0V
star (Teff = 5241 ± 50 K) with a period of 2.49970
days, and a V = 12.80 F8V star (Teff = 6330 ± 130 K)
in 4.43527 days, respectively. The transits were independently verified
by follow-up photometric observations with the SAAO 1.0-m and Euler
telescopes, and we report on the planetary parameters using HARPS, FEROS
and CORALIE radial velocities. NGTS-8b has a mass, 0.93 ^{+0.04}_{-0.03}
MJ and a radius, 1.09 ± 0.03 RJ similar to
Jupiter, resulting in a density of 0.89 ^{+0.08}_{-0.07} g
cm-3. This is in contrast to NGTS-9b, which has a mass of
2.90 ± 0.17 MJ and a radius of 1.07 ± 0.06
RJ, resulting in a much greater density of
2.93^{+0.53}_{-0.49} g cm-3. Statistically, the planetary
parameters put both objects in the regime where they would be expected
to exhibit larger than predicted radii. However, we find that their
radii are in agreement with predictions by theoretical non-inflated
models.
KW - techniques: photometric
KW - stars: individual: NGTS-8 and NGTS-9 planetary systems
KW - planets and satellites: detection
U2 - 10.1093/mnras/stz3140
DO - 10.1093/mnras/stz3140
M3 - Article
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
ER -