scholarly journals Exomoon candidates from transit timing variations: eightKeplersystems with TTVs explainable by photometrically unseen exomoons

2020 ◽  
Vol 501 (2) ◽  
pp. 2378-2393
Author(s):  
Chris Fox ◽  
Paul Wiegert

ABSTRACT If a transiting exoplanet has a moon, that moon could be detected directly from the transit it produces itself, or indirectly via the transit timing variations (TTVs) it produces in its parent planet. There is a range of parameter space where the Kepler Space Telescope is sensitive to the TTVs exomoons might produce, though the moons themselves would be too small to detect photometrically via their own transits. The Earth’s Moon, for example, produces TTVs of 2.6 min amplitude by causing our planet to move around their mutual centre of mass. This is more than Kepler’s short-cadence interval of 1 min and so nominally detectable (if transit timings can be measured with comparable accuracy), even though the Moon’s transit signature is only 7 per cent that of Earth’s, well below Kepler’s nominal photometric threshold. Here, we examine several Kepler systems, exploring the hypothesis that an exomoon could be detected solely from the TTVs it induces on its host planet. We compare this with the alternate hypothesis that the TTVs are caused by an non-transiting planet in the system. We examine 13 Kepler systems and find 8 where both hypotheses explain the observed TTVs equally well. Though no definitive exomoon detection can be claimed on this basis, the observations are nevertheless completely consistent with a dynamically stable moon small enough to fall below Kepler’s photometric threshold for transit detection, and these systems warrant further observation and analysis.

2020 ◽  
Vol 498 (1) ◽  
pp. 33-43
Author(s):  
R Ridden-Harper ◽  
B E Tucker ◽  
M Gully-Santiago ◽  
G Barentsen ◽  
A Rest ◽  
...  

ABSTRACT The K2 mission of the Kepler Space Telescope offers a unique possibility to examine sources of both Galactic and extragalactic origin with high-cadence photometry. Alongside the multitude of supernovae and quasars detected within targeted galaxies, it is likely that Kepler has serendipitously observed many transients throughout K2. Such events will likely have occurred in background pixels, coincidentally surrounding science targets. Analysing the background pixels presents the possibility to conduct a high-cadence survey with areas of a few square degrees per campaign. We demonstrate the capacity to independently recover key K2 transients such as KSN 2015K and SN 2018oh. With this survey, we expect to detect numerous transients and determine the first comprehensive rates for transients with lifetimes of ≤1 d.


2014 ◽  
Vol 445 (3) ◽  
pp. 2810-2817 ◽  
Author(s):  
E. Plachy ◽  
J. M. Benkő ◽  
Z. Kolláth ◽  
L. Molnár ◽  
R. Szabó

2008 ◽  
Author(s):  
D. A. Sheikh ◽  
S. J. Connell ◽  
R. S. Dummer

2018 ◽  
Vol 62 (5) ◽  
pp. 352-358
Author(s):  
I. S. Savanov ◽  
E. S. Kalinicheva ◽  
E. S. Dmitrienko

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