J/A+A/652/A117 Transit search in the V1400 Cen system (Barmentloo+, 2021)
A search for transiting companions in the J1407 (V1400 Cen) system.
Barmentloo S., Dik C., Kenworthy M.A., Mamajek E.E., Hambsch F.-J.,
Reichart D.E., Rodriguez J.E., van Dam D.M.
<Astron. Astrophys. 652, A117 (2021)>
=2021A&A...652A.117B 2021A&A...652A.117B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry, CCD
Keywords: planets and satellites: rings - stars: activity - dynamo -
planets and satellites: detection
Abstract:
In 2007, the young star 1SWASP J140747.93-394542.6 (V1400 Cen)
underwent a complex series of deep eclipses over 56 days. This was
attributed to the transit of a ring system filling a large fraction of
the Hill sphere of an unseen substellar companion. Subsequent
photometric monitoring has not found any other deep transits from this
candidate ring system, but if there are more substellar companions and
if they are coplanar with the potential ring system, there is a chance
that they will transit the star as well.
This young star is active, and the light curves show a 5% modulation
in amplitude with a dominant rotation period of 3.2 days due to
starspots rotating into and out of view. We model and remove the
rotational modulation of the J1407 light curve and search for
additional transit signatures of substellar companions orbiting around
J1407.
We combine the photometry of J1407 from several observatories,
spanning a 19 year baseline. We remove the rotational modulation by
modeling the variability as a periodic signal, whose periodicity
changes slowly with time over several years due to the activity cycle
of the star.
A transit least squares (TLS) analysis is used to search for any
periodic transiting signals within the cleaned light curve. We
identify an activity cycle of J1407 with a period of 5.4yr. A TLS
search does not find any plausible periodic eclipses in the light
curve, from 1.2% amplitude at 5 days up to 1.9% at 20 days. This
sensitivity is confirmed by injecting artificial transits into the
light curve and determining the recovery fraction as a function of
transit depth and orbital period. J1407 is confirmed as a young active
star with an activity cycle consistent with a rapidly rotating solar
mass star.
With the rotational modulation removed, the TLS analysis reaches down
to planetary mass radii for young exoplanets, ruling out transiting
companions with radii larger than about 1RJup.
Description:
Photometry from five ground-based telescopes of the star V1400 Cen
with a model for the periodic modulation due to star spots removed.
This data was used to search for transiting exoplanets and to
characterise a multi-year variation in the rotational modulation,
attributed to the activity cycle of the star.
Objects:
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RA (2000) DE Designation(s)
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14 07 47.9 -39 45 43 J1407 = V1400 Cen = 1SWASP J140747.93-394542.6
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
j1407.dat 34 9843 Photometry corrected for stellar activity
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See also:
J/A+A/633/A115 : ALMA and NACO observations towards V1400 Cen (Kenworthy+ 2020)
Byte-by-byte Description of file: j1407.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d MJD [51887.35/58971.01] Epoch in MJD
13- 18 F6.4 --- Flux [0.53/1.61] Normalised Uncorrected Flux
20- 25 F6.4 --- Fluxcorr [0.89/1.13] Normalised Corrected Flux
27- 32 F6.4 --- e_Flux [0.0/0.05] Error on Flux
34 I1 --- Telnum [1/5] Telescope number (1)
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Note (1): Telescope number as follows:
1 = ASAS
2 = ASAS-SN
3 = KELT
4 = PROMPT
5 = ROAD
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Acknowledgements:
M.A. Kenworthy, kenworthy(at)strw.leidenuniv.nl
(End) M.A. Kenworthy [Leiden], Patricia Vannier [CDS] 08-Jul-2021