J/MNRAS/523/3069 HIP 9618 light and radial velocity curves (Osborn+, 2023)
Two warm Neptunes transiting HIP 9618 revealed by TESS & Cheops.
Osborn H.P., Nowak G., Hebrard G., Masseron T., Lillo-Box J., Palle E.,
Bekkelien A., Floren H.-G., Guterman P., Simon A.E., Adibekyan V.,
Bieryla A., Borsato L., Brandeker A., Ciardi D.R., Collier Cameron A.,
Collins K.A., Egger J.A., Gandolfi D., Hooton M.J., Latham D.W.,
Lendl M., Matthews E.C., Tuson A., Ulmer-Moll S., Vanderburg A.,
Wilson T.G., Ziegler C., Alibert Y., Alonso R., Anglada G., Arnold L.,
Asquier J., Barrado y Navascues D., Baumjohann W., Beck T.,
Belinski A.A., Benz W., Biondi F., Boisse I., Bonfils X., Broeg C.,
Buchhave L.A., Barczy T., Barros S.C.C., Cabrera J., Cardona Guillen C.,
Carleo I., Castro-Gonzalez A., Charnoz S., Christiansen J.,
Cortes-Zuleta P., Csizmadia S., Dalal S., Davies M.B., Deleuil M.,
Delfosse X., Delrez L., Demory B.-O., Dunlavey A.B., Ehrenreich D.,
Erikson A., Fernandes R.B., Fortier A., Forveille T., Fossati L.,
Fridlund M., Gillon M., Goeke R.F., Goliguzova M.V., Gonzales E.J.,
Guenther M.N., Guedel M., Heidari N., Henze C.E., Howell S., Hoyer S.,
Frey J.I., Isaak K.G., Jenkins J.M., Kiefer F., Kiss L., Korth J.,
Maxted P.F.L., Laskar J., Lecavelier des Etangs A., Lovis C., Lund M.B.,
Luque R., Magrin D., Almenara J.M., Martioli E., Mecina M., Medina J.V.,
Moldovan D., Morales-Calderon M., Morello G., Moutou C., Murgas F.,
Jensen E.L.N., Nascimbeni V., Olofsson G., Ottensamer R., Pagano I.,
Peter G., Piotto G., Pollacco D., Queloz D., Ragazzoni R., Rando N.,
Rauer H., Ribas I., Ricker G., Demangeon O.D.S., Smith A.M.S., Santos N.,
Scandariato G., Seager S., Sousa S.G., Steller M., Szabo G.M.,
Segransan D., Thomas N., Udry S., Ulmer B., Van Grootel V.,
Vanderspek R., Walton N., Winn J.N.
<Mon. Not. R. Astron. Soc. 523, 3069-3089 (2023)>
=2023MNRAS.523.3069O 2023MNRAS.523.3069O (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ; Optical ;
Radial velocities
Keywords: surveys - eclipses - occultations -
planets and satellites: detection - binaries: spectroscopic
Abstract:
HIP 9618 (HD 12572, TOI-1471, TIC 306263608) is a bright (G=9.0mag)
solar analogue. TESS photometry revealed the star to have two
candidate planets with radii of 3.9±0.044 R⊕ (HIP 9618 b) and
3.343±0.039R⊕ (HIP 9618 c). While the 20.77291 d period of HIP
9618 b was measured unambiguously, HIP 9618 c showed only two transits
separated by a 680-d gap in the time series, leaving many
possibilities for the period. To solve this issue, CHEOPS performed
targeted photometry of period aliases to attempt to recover the true
period of planet c, and successfully determined the true period to be
52.56349 d. High-resolution spectroscopy with HARPS-N, SOPHIE, and
CAFE revealed a mass of 10.0±3.1M⊕ for HIP 9618 b, which,
according to our interior structure models, corresponds to a 6.8±1.4
per cent gas fraction. HIP 9618 c appears to have a lower mass than
HIP 9618 b, with a 3-sigma upper limit of <18M⊕. Follow-up and
archival RV measurements also reveal a clear long-term trend which,
when combined with imaging and astrometric information, reveal a
low-mass companion (0.08+0.12-0.05M☉) orbiting at
26.0+19.0-11.0au. This detection makes HIP 9618 one of only five
bright (K<8mag) transiting multiplanet systems known to host a planet
with P>50d, opening the door for the atmospheric characterization of
warm (Teq<750K) sub-Neptunes.
Description:
CHEOPS photometry (filekeys PR110048TG017201V0200 &
PR110048TG017301V0200 & PR110048TG017401V0200 &
PR110048TG017601V0200), RVs from HARPS-N SOPHIE & CAFE, and
ground-based photometry (LCO at McD, CTOI & SAAO) used in the
detection paper of the HIP 9618b & c.
Objects:
---------------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------------
02 03 37.02 +21 16 51.1 HIP 9618 = BD+20 328
---------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
cheops.dat 645 1865 CHEOPS photometry and model fits
harpsnrv.dat 515 13 HARPS-N RV data and model fits
sophierv.dat 515 27 SOPHIE RV data and model fits
caferv.dat 515 9 CAFE RV data and model fits
lco_mcd.dat 39 374 LCO ground-based photometry [McDonald 1-meter]
lco_ctio.dat 42 414 LCO ground-based photometry [CTIO 1-meter]
lco_saao.dat 39 640 LCO ground-based photometry [SAAO 1-meter]
--------------------------------------------------------------------------------
Byte-by-byte Description of file: cheops.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.13 --- Time Time (BJD-2457000) (Time)
20- 41 E22.16 10-3 Flux Normalised Flux (normalised to zero
with variation in ppt) (Flux_ppt)
43- 61 F19.17 10-3 e_Flux Normalised Flux Error
(Fluxerrppt)
63- 80 F18.14 deg Rollangle Telescope roll angle (Rollangle_deg)
82-104 A23 --- Filekey CHEOPS unique visit file key
(filekey)
106-128 F23.20 --- Normsinrollangle Sin of roll angle normalised such
that mu=0 & sigma=1
(Normsinrollangle)
130-151 F22.19 --- Normcosrollangle Cos of roll angle normalised such
that mu=0 & sigma=1
(Normcosrollangle)
153-176 E24.17 --- NormBGflux Background flux normalised such that
mu=0 & sigma=1 (NormBGflux)
178-197 F20.17 10-3 FluxCorModel-2sig Modelled 2-sigma lower errors for
decorrelation+polynomial
(FluxCorModel_-2sig)
199-218 F20.17 10-3 SplineCorModel-2sig Modelled bspline model 2-sigma lower
errors (SplineCorModel_-2sig)
220-222 F3.1 10-3 PlanetbModel-2sig Modelled planet b transit model
2-sigma lower errors
(PlanetbModel_-2sig)
224-245 F22.19 10-3 PlanetcModel-2sig Modelled planet c transit model
2-sigma lower errors
(PlanetcModel_-2sig)
247-266 F20.17 10-3 TotalModel-2sig Combined model w
decorrelation+spline+transits
-2-sigma (TotalModel-2sig)
268-290 E23.17 10-3 FluxCorModel-1sig Modelled 1-sigma lower errors for
decorrelation+polynomial
(FluxCorModel_-1sig)
292-312 F21.18 10-3 SplineCorModel-1sig Modelled bspline model 1-sigma lower
errors (SplineCorModel_-1sig)
314-316 F3.1 10-3 PlanetbModel-1sig Modelled planet b transit model
1-sigma lower errors
(PlanetbModel_-1sig)
318-338 F21.18 10-3 PlanetcModel-1sig Modelled planet c transit model
1-sigma lower errors
(PlanetcModel_-1sig)
340-361 F22.19 10-3 TotalModel-1sig Combined model w
decorrelation+spline+transits
-1-sigma (TotalModel-1sig)
363-384 E22.16 10-3 FluxCorModelmed Modelled median/best-fit for
decorrelation+polynomial
(FluxCorModel_med)
386-407 E22.16 10-3 SplineCorModelmed Modelled bspline model model
median/best-fit
(SplineCorModel_med)
409-411 F3.1 10-3 PlanetbModelmed Modelled planet b transit model
model median/best-fit
(PlanetbModel_med)
413-434 F22.19 10-3 PlanetcModelmed Modelled planet c transit model
model median/best-fit
(PlanetcModel_med)
436-457 E22.16 10-3 TotalModelmed Combined model w
decorrelation+spline+transits model
median (TotalModelmed)
459-481 E23.16 10-3 FluxCorModel+1sig Modelled 1-sigma upper errors for
decorrelation+polynomial
(FluxCorModel_+1sig)
483-505 F23.20 10-3 SplineCorModel+1sig Modelled bspline model 1-sigma upper
errors (SplineCorModel_+1sig)
507-509 F3.1 10-3 PlanetbModel+1sig Modelled planet b transit model
1-sigma upper errors
(PlanetbModel_+1sig)
511-532 F22.19 10-3 PlanetcModel+1sig Modelled planet c transit model
1-sigma upper errors
(PlanetcModel_+1sig)
534-556 E23.16 10-3 TotalModel+1sig Combined model w
decorrelation+spline+transits
+1-sigma (TotalModel+1sig)
558-576 F19.17 10-3 FluxCorModel+2sig Modelled 2-sigma upper errors for
decorrelation+polynomial
(FluxCorModel_+2sig)
578-596 F19.17 10-3 SplineCorModel+2sig Modelled bspline model 2-sigma upper
errors (SplineCorModel_+2sig)
598-600 F3.1 10-3 PlanetbModel+2sig Modelled planet b transit model
2-sigma upper errors
(PlanetbModel_+2sig)
602-622 F21.18 10-3 PlanetcModel+2sig Modelled planet c transit model
2-sigma upper errors
(PlanetcModel_+2sig)
624-645 F22.19 10-3 TotalModel+2sig Combined model w
decorrelation+spline+transits
+2-sigma (TotalModel+2sig)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: caferv.dat harpsnrv.dat sophierv.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.12 --- Time Time (BJD-2400000) (Time)
20- 39 F20.13 m/s RV Radial Velocity (RV_ms)
41- 61 F21.16 m/s e_RV Radial Velocity Uncertainty (eRV_ms)
63- 82 F20.17 m/s RVb-2sig Modelled 2-sigma lower errors for planet b
(rvb-2sig)
84-104 F21.18 m/s RVc-2sig Modelled 2-sigma lower errors for planet c
(rvc-2sig)
106-128 F23.16 --- bkg-2sig Modelled 2-sigma lower errors for
Background/trend model (bkg_-2sig)
130-152 F23.16 --- model-2sig Modelled 2-sigma lower errors for full model
(pls+background) (model_-2sig)
154-173 F20.17 m/s RVb-1sig Modelled 1-sigma lower error for planet b
(rvb-1sig)
175-195 F21.18 m/s RVc-1sig Modelled 1-sigma lower error for planet c
(rvc-1sig)
197-219 F23.16 --- bkg-1sig Modelled 1-sigma lower error for
Background/trend model (bkg_-1sig)
221-243 F23.16 --- model-1sig Modelled 1-sigma lower errors for full model
(pls+background) (model_-1sig)
245-264 F20.17 m/s RVbmed Model median/best-fit for planet b (rvbmed)
266-286 F21.18 m/s RVcmed Model median/best-fit for planet c (rvcmed)
288-310 F23.16 --- bkgmed Model median/best-fit for
Background/trend model (bkg_med)
312-334 F23.16 --- modelmed Model median/best-fit for full model
(pls+background) (model_med)
336-355 F20.17 m/s RVb+1sig Modelled 1-sigma upper errors for planet b
(rvb+1sig)
357-376 F20.17 m/s RVc+1sig Modelled 1-sigma upper errors for planet c
(rvc+1sig)
378-400 F23.16 --- bkg+1sig Modelled 1-sigma upper errors for
Background/trend model (bkg_+1sig)
402-424 F23.16 --- model+1sig Modelled 1-sigma upper errors for full model
(pls+background) (model_+1sig)
426-445 F20.17 m/s RVb+2sig Modelled 2-sigma upper errors for planet b
(rvb+2sig)
447-467 F21.18 m/s RVc+2sig Modelled 2-sigma upper errors for planet c
(rvc+2sig)
469-491 F23.16 --- bkg+2sig Modelled 2-sigma upper errors for
Background/trend model (bkg_+2sig)
493-515 F23.16 --- model+2sig Modelled 2-sigma upper errors for full model
(pls+background) (model_+2sig)
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Byte-by-byte Description of file: lco_ctio.dat lco_mcd.dat lco_saao.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.12 --- Time Heliocentric Time (BJD-2400000)
20- 30 F11.9 --- RelFlux Relative photometric flux (normalised to 1.0)
32- 42 F11.9 --- e_RelFlux Relative photometric flux error
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Acknowledgements:
Hugh Osborn, hugh.osborn(at)unibe.ch
(End) Patricia Vannier [CDS] 25-Apr-2023