J/A+A/668/A117 HD 108236 system observed with CHEOPS and TESS (Hoyer+, 2022)
Characterization of the HD 108236 system with CHEOPS and TESS.
Confirmation of a fifth transiting planet.
Hoyer S., Bonfanti A., Leleu A., Acuna L., Serrano L.M., Deleuil M.,
Bekkelien A., Broeg C., Floren H.-G., Queloz D., Wilson T.G., Sousa S.G.,
Hooton M.J., Adibekyan V., Alibert Y., Alonso R., Anglada G., Asquier J.,
Barczy T., Barrado D., Barros S.C.C., Baumjohann W., Beck M., Beck T.,
Benz W., Billot N., Biondi F., Bonfils X., Brandeker A., Cabrera J.,
Charnoz S., Collier Cameron A., Csizmadia Sz., Davies M.B., Delrez L.,
Demangeon O.D.S., Demory B.-O., Ehrenreich D., Erikson A., Fortier A.,
Fossati L., Fridlund M., Gandolfi D., Gillon M., Gudel M., Hara N., Heng K.,
Isaak K.G., Jenkins J.M., Kiss L.L., Laskar J., Latham D.W.,
Lecavelier des Etangs A., Lendl M., Lovis C., Luntzer A., Magrin D.,
Maxted P.F.L., Nascimbeni V., Olofsson G., Ottensamer R., Pagano I.,
Palle E., Persson C.M., Peter G., Piazza D., Piotto G., Pollacco D.,
Ragazzoni R., Rando N., Rauer H., Ribas I., Ricker G.R., Salmon S.,
Santos N.C., Scandariato G., Seager S., Segransan D., Simon A.E.,
Smith A.M.S., Steller M., Szabo Gy.M., Thomas N., Twicken J.D., Udry S.,
Van Grootel V., Vanderspek R.K., Walton N.A., Westerdorff K., Winn J.N.
<Astron. Astrophys. 668, A117 (2022)>
=2022A&A...668A.117H 2022A&A...668A.117H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ; Optical
Keywords: planetary systems - planets and satellites: detection -
planets and satellites: fundamental parameters -
planets and satellites: individual: HD 108236 -
planets and satellites: individual: TOI-1233
Abstract:
The HD 108236 system was first announced with the detection of four
small planets based on TESS data. Shortly after, the transit of an
additional planet with a period of 29.54d was serendipitously detected
by CHEOPS. In this way, HD 108236 (V=9.2) became one of the brightest
stars known to host five small transiting planets (Rp<3REarth).
We characterize the planetary system by using all the data available
from CHEOPS and TESS space missions. We use the flexible pointing
capabilities of CHEOPS to follow up the transits of all the planets in
the system, including the fifth transiting body.
After updating the host star parameters by using the results from Gaia
eDR3, we analyzed 16 and 43 transits observed by CHEOPS and TESS,
respectively, to derive the planets physical and orbital parameters.
We carried out a timing analysis of the transits of each of the
planets of HD 108236 to search for the presence of transit timing
variations.
We derived improved values for the radius and mass of the host star
(Rstar=0.876±0.007R☉ and
Mstar=0.867-0.046+0.047M☉). We confirm the presence of the
fifth transiting planet f in a 29.54d orbit. Thus, the HD 108236
system consists of five planets of Rb=1.587±0.028,
Rc=2.122±0.025, Rd=2.629±0.031, Re=3.008±0.032, and
Rf=1.89±0.04[REarth]. We refine the transit ephemeris for each
planet and find no significant transit timing variations for planets
c, d, and e. For planets b and f, instead, we measure significant
deviations on their transit times (up to 22 and 28min, respectively)
with a non-negligible dispersion of 9.6 and 12.6min in their time
residuals.
We confirm the presence of planet f and find no significant evidence
for a potential transiting planet in a 10.9d orbital period, as
previously suggested. Further monitoring of the transits, particularly
for planets b and f, would confirm the presence of the observed
transit time variations. HD 108236 thus becomes a key multi-planetary
system for the study of formation and evolution processes. The
reported precise results on the planetary radii -- together with a
profuse RV monitoring -- will allow for an accurate characterization
of the internal structure of these planets.
Description:
Photometric time series of HD108236 obtained by CHEOPS during the
transits of planet b, c, d, e, and f. The provided flux corresponds to
the roll angle detrended normalized flux.
Objects:
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RA (2000) DE Designation(s)
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12 26 17.89 -51 21 46.2 HD 108236 = TOI-1233
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tg000101.dat 249 786 Photometric data visit 1.
Transits of planets c, e, (g)
tg015701.dat 249 666 Photometric data visit 2. Transits of planet b
tg015401.dat 249 697 Photometric data visit 3. Transits of planet d
tg015601.dat 249 409 Photometric data visit 4. Transits of planet c
tg015702.dat 249 609 Photometric data visit 5.
Transits of planets b and f
tg015602.dat 249 420 Photometric data visit 6. Transits of planet c
tg022401.dat 249 284 Photometric data visit 7. Transits of planet c
tg023001.dat 249 364 Photometric data visit 8. Transits of planet b
tg024301.dat 249 935 Photometric data visit 9.
Transits of planets d and g
tg023002.dat 249 286 Photometric data visit 10. Transits of planet b
tg022701.dat 249 480 Photometric data visit 11. Transits of planet e
tg023003.dat 249 340 Photometric data visit 12. Transits of planet b
tg022901.dat 249 392 Photometric data visit 13. Transits of planet c
tg002601.dat 249 450 Photometric data visit 14. Transits of planet f
tg002701.dat 249 657 Photometric data visit 15. Transits of planet g
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Byte-by-byte Description of file: tg*.dat
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Bytes Format Units Label Explanations
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1- 24 E24.19 d Time Time of observation (BJD)
26- 49 E24.19 --- NFlux Detrended normalised flux
51- 74 E24.19 --- e_NFlux Error on detrended normalised flux
76- 99 E24.19 deg Roll Roll angle of the observation
101-124 E24.19 ct Bkg Background
126-149 E24.19 pix Xloc X location of target in CCD
151-174 E24.19 pix Yloc Y location of target in CCD
176-199 E24.19 pix Xcnt X centroid of the target PSF
201-224 E24.19 pix Ycnt Y centroid of the target PSF
226-249 E24.19 ct Contam Estimated contamination from background stars
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Acknowledgements:
Sergio Hoyer, sergio.hoyer(at)lam.fr
(End) Patricia Vannier [CDS] 06-Oct-2022