We present the discovery and characterization of two transiting planets observed by TESS in the light curves of the young and bright (V = 9.67) star HD73583 (TOI-560). We perform an intensive ...spectroscopic and photometric space- and ground-based follow-up in order to confirm and characterize the system. We found that HD73583 is a young (similar to 500 Myr) active star with a rotational period of 12.08 +/- 0.11 d, and a mass and radius of 0.73 +/- 0.02 M-circle dot and 0.65 +/- 0.02 R-circle dot, respectively. HD 73583 b (P-b = 6.3980420(-0.0000062)(+0.0000067 )d) has a mass and radius of 10.2(-3.1)(+3.4) M-circle plus and 2.79 +/- 0.10 R-circle plus, respectively, which gives a density of 2.58(-0.81)(+0.95) g cm(-3). HD 73583 c (P-c = 18.87974(-0.00074)(+0.00086) d) has a mass and radius of 9.7(-1.7)(+1.8) M-circle plus and 2.39(-0.09)(+0.10) R-circle plus, respectively, which translates to a density of 3.88(-0.80)(+0.91) g cm(-3). Both planets are consistent with worlds made of a solid core surrounded by a volatile envelope. Because of their youth and host star brightness, they both are excellent candidates to perform transmission spectroscopy studies. We expect ongoing atmospheric mass-loss for both planets caused by stellar irradiation. We estimate that the detection of evaporating signatures on H and He would be challenging, but doable with present and future instruments.
We derive the microscopic spectral density of the Dirac operator in
SU(
N
c
⩾ 3) Yang-Mills theory coupled to
N
f
fermions in the fundamental representation. An essential technical ingredient is an ...exact rewriting of this density in terms of integrations over the super Riemannian manifold
Gl (N
f +
1
1
)
. The result agrees exactly with earlier calculations based on Random Matrix Theory.
ABSTRACT
To date, thousands of planets have been discovered, but there are regions of the orbital parameter space that are still bare. An example is the short period and intermediate mass/radius ...space known as the ‘Neptunian desert’, where planets should be easy to find but discoveries remain few. This suggests unusual formation and evolution processes are responsible for the planets residing here. We present the discovery of TOI-332 b, a planet with an ultra-short period of 0.78 d that sits firmly within the desert. It orbits a K0 dwarf with an effective temperature of 5251 ± 71 K. TOI-332 b has a radius of $3.20^{+0.16}_{-0.12}$ R⊕, smaller than that of Neptune, but an unusually large mass of 57.2 ± 1.6 M⊕. It has one of the highest densities of any Neptune-sized planet discovered thus far at $9.6^{+1.1}_{-1.3}$ g cm−3. A 4-layer internal structure model indicates it likely has a negligible hydrogen-helium envelope, something only found for a small handful of planets this massive, and so TOI-332 b presents an interesting challenge to planetary formation theories. We find that photoevaporation cannot account for the mass-loss required to strip this planet of the Jupiter-like envelope it would have been expected to accrete. We need to look towards other scenarios, such as high-eccentricity migration, giant impacts, or gap opening in the protoplanetary disc, to try and explain this unusual discovery.
TOI-220b: a warm sub-Neptune discovered by TESS Hoyer, S.; Gandolfi, D.; Armstrong, D. J. ...
Monthly notices of the Royal Astronomical Society,
08/2021, Letnik:
505, Številka:
3
Journal Article
Recenzirano
Odprti dostop
In this paper, we report the discovery of TOI-220b, a new sub-Neptune detected by the Transiting Exoplanet Survey Satellite (TESS) and confirmed by radial velocity follow-up observations with the ...HARPS spectrograph. Based on the combined analysis of TESS transit photometry and high precision radial velocity measurements, we estimate a planetary mass of 13.8 +/- 1.0M(circle plus) and radius of 3.03 +/- 0.15R(circle plus), implying a bulk density of 2.73 +/- 0.47. TOI-220b orbits a relative bright (V=10.4) and old (10.1 +/- 1.4Gyr) K dwarf star with a period of similar to 10.69d. Thus, TOI-220b is a new warm sub-Neptune with very precise mass and radius determinations. A Bayesian analysis of the TOI-220b internal structure indicates that due to the strong irradiation it receives, the low density of this planet could be explained with a steam atmosphere in radiative-convective equilibrium and a supercritical water layer on top of a differentiated interior made of a silicate mantle and a small iron core.
We report three newly discovered exoplanets from the SuperWASP survey. WASP-127b is a heavily inflated super-Neptune of mass 0.18±0.02 MJ and radius 1.37±0.04 RJ. This is one of the least massive ...planets discovered by the WASP project. It orbits a bright host star (Vmag = 10.16) of spectral type G5 with a period of 4.17 days. WASP-127b is a low-density planet that has an extended atmosphere with a scale height of 2500 ± 400 km, making it an ideal candidate for transmission spectroscopy. WASP-136b and WASP-138b are both hot Jupiters with mass and radii of 1.51 ± 0.08 MJ and 1.38 ± 0.16 RJ, and 1.22 ± 0.08 MJ and 1.09 ± 0.05 RJ, respectively. WASP-136b is in a 5.22-day orbit around an F9 subgiant star with a mass of 1.41 ± 0.07 M⊙ and a radius of 2.21 ± 0.22 R⊙. The discovery of WASP-136b could help constrain the characteristics of the giant planet population around evolved stars. WASP-138b orbits an F7 star with a period of 3.63 days. Its radius agrees with theoretical values from standard models, suggesting the presence of a heavy element core with a mass of ~ 10 M⊕. The discovery of these new planets helps in exploring the diverse compositional range of short-period planets, and will aid our understanding of the physical characteristics of both gas giants and low-density planets.
Context.
The current architecture of a given multi-planetary system is a key fingerprint of its past formation and dynamical evolution history. Long-term follow-up observations are key to complete ...their picture.
Aims.
In this paper, we focus on the confirmation and characterization of the components of the TOI-969 planetary system, where TESS detected a Neptune-size planet candidate in a very close-in orbit around a late K-dwarf star.
Methods.
We use a set of precise radial velocity observations from HARPS, PFS, and CORALIE instruments covering more than two years in combination with the TESS photometric light curve and other ground-based follow-up observations to confirm and characterize the components of this planetary system.
Results.
We find that TOI-969 b is a transiting close-in (
P
b
~ 1.82 days) mini-Neptune planet (
m
b
= 9.1
−1.0
+1.1
M
⊕
,
R
b
= 2.765
−0.097
+0.088
R
⊕
), placing it on the lower boundary of the hot-Neptune desert (
T
eq,b
= 941 ± 31 K). The analysis of its internal structure shows that TOI-969 b is a volatile-rich planet, suggesting it underwent an inward migration. The radial velocity model also favors the presence of a second massive body in the system, TOI-969 c, with a long period of
P
c
= 1700
−280
+290
days, a minimum mass of
m
c
sin
i
c
= 11.3
−0.9
+1.1
M
Jup
, and a highly eccentric orbit of
e
c
= 0.628
−0.036
+0.043
.
Conclusions.
The TOI-969 planetary system is one of the few around K-dwarfs known to have this extended configuration going from a very close-in planet to a wide-separation gaseous giant. TOI-969 b has a transmission spectroscopy metric of 93 and orbits a moderately bright (
G
= 11.3 mag) star, making it an excellent target for atmospheric studies. The architecture of this planetary system can also provide valuable information about migration and formation of planetary systems.
Context.
Long-period transiting planets provide the opportunity to better understand the formation and evolution of planetary systems. Their atmospheric properties remain largely unaltered by tidal ...or radiative effects of the host star, and their orbital arrangement reflects a different and less extreme migrational history compared to close-in objects. The sample of long-period exoplanets with well-determined masses and radii is still limited, but a growing number of long-period objects reveal themselves in the Transiting Exoplanet Survey Satellite (TESS) data.
Aims.
Our goal is to vet and confirm single-transit planet candidates detected in the TESS space-based photometric data through spectroscopic and photometric follow-up observations with ground-based instruments.
Methods.
We used high-resolution spectrographs to confirm the planetary nature of the transiting candidates and measure their masses. We also used the Next Generation Transit Survey (NGTS) to photometrically monitor the candidates in order to observe additional transits. Using a joint modeling of the light curves and radial velocities, we computed the orbital parameters of the system and were able to precisely measure the mass and radius of the transiting planets.
Results.
We report the discovery of two massive, warm Jupiter-size planets, one orbiting the F8-type star TOI-5153 and the other orbiting the G1-type star NGTS-20 (=TOI-5152). From our spectroscopic analysis, both stars are metal rich with a metallicity of 0.12 and 0.15, respectively. Only TOI-5153 presents a second transit in the TESS extended mission data, but NGTS observed NGTS-20 as part of its mono-transit follow-up program and detected two additional transits. Follow-up high-resolution spectroscopic observations were carried out with CORALIE, CHIRON, FEROS, and HARPS. TOI-5153 hosts a planet with a period of 20.33 days, a planetary mass of 3.26
−0.17
+0.18
Jupiter masses (
M
J
), a radius of 1.06
−0.04
+0.04
R
J
, and an orbital eccentricity of 0.091
−0.026
+0.024
. NGTS-20 b is a 2.98
−0.15
+0.16
M
J
planet with a radius of 1.07
−0.04
+0.04
R
J
on an eccentric 0.432
−0.023
+0.023
orbit with an orbital period of 54.19 days. Both planets are metal enriched and their heavy element content is in line with the previously reported mass-metallicity relation for gas giants.
Conclusions.
Both warm Jupiters orbit moderately bright host stars, making these objects valuable targets for follow-up studies of the planetary atmosphere and measurement of the spin-orbit angle of the system.
Context.
High-precision planetary densities are key pieces of information necessary to derive robust atmospheric properties for extrasolar planets. Measuring precise masses is the most challenging ...part of this task, especially in multi-planetary systems. The ESO-K2 collaboration focuses on the follow-up of a selection of multi-planetary systems detected by the K2 mission using the HARPS instrument with this goal in mind.
Aims.
In this work, we measure the masses and densities of two multi-planetary systems: a four-planet near resonant chain system (K2-32) and a young (~400 Myr old) planetary system consisting of three close-in small planets (K2-233).
Methods.
We obtained 199 new HARPS observations for K2-32 and 124 for K2-233 covering a long baseline of more than three years. We performed a joint analysis of the radial velocities and K2 photometry with
PASTIS
to precisely measure and constrained the properties of these planets, focusing on their masses and orbital properties.
Results.
We find that K2-32 is a compact scaled-down version of the Solar System’s architecture, with a small rocky inner planet (
M
e
= 2.1
−1.1
+1.3
M
⊕
,
P
e
~ 4.35 days) followed by an inflated Neptune-mass planet (
M
b
= 15.0
−1.7
+1.8
M
⊕
,
P
b
~ 8.99 days) and two external sub-Neptunes (
M
c
= 8.1 ± 2.4
M
⊕
,
P
c
~ 20.66 days;
M
d
= 6.7 ± 2.5
M
⊕
,
P
d
~ 31.72 days). K2-32 becomes one of the few multi-planetary systems with four or more planets known where all have measured masses and radii. Additionally, we constrain the masses of the three planets in the K2-233 system through marginal detection of their induced radial velocity variations. For the two inner Earth-size planets we constrain their masses at a 95% confidence level to be smaller than
M
b
< 11.3
M
⊕
(
P
b
~ 2.47 days),
M
c
< 12.8
M
⊕
(
P
c
~ 7.06 days). The outer planet is a sub-Neptune size planet with an inferred mass of
M
d
= 8.3
−4.7
+5.2
M
⊕
(
M
d
< 21.1
M
⊕
,
P
d
~ 24.36 days).
Conclusions.
Our observations of these two planetary systems confirm for the first time the rocky nature of two planets orbiting a young star, with relatively short orbital periods (<7 days). They provide key information for planet formation and evolution models of telluric planets. Additionally, the Neptune-like derived masses of the three planets, K2-32 b, c, d, puts them in a relatively unexplored regime of incident flux and planet mass, which is key for transmission spectroscopy studies in the near future.
We describe the design and performance the calorimeter systems used in the ECCE detector to achieve the overall performance specifications cost-effectively with careful consideration of appropriate ...technical and schedule risks. The calorimeter systems consist of three electromagnetic calorimeters, covering the combined pseudorapidity range from −3.7 to 3.8 and two hadronic calorimeters covering a combined range of −1.1<η<3.8. Key calorimeter performances which include energy and position resolutions, reconstruction efficiency, and particle identification will be presented.
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