text:   Transit Timing Variations",9,"['****New Paper Alert** \n\nToday my group at @Cornell @CSInst (@AstroAndrew123, @DrRayJay, &amp; I) published a new paper using @NASA_TESS data \n\n""TESS Observations of the Hot Jupiter Exoplanet XO-6b: No Evidence of Transit Timing Variations"" \n\n<LINK>\n\nTHREAD 1/8 <LINK>', 'XO-6b is a typical hot Jupiter that orbits a F5V-type star.\n\nPrevious ground-based observations by Garai et al. 2020 (https://t.co/hHQWrbQTM1) find transit timing variations (TTvs) with an amplitude of 14 min &amp; period of  450 days\n\n2/8 https://t.co/6BSYRupp2u', ""Inspired by the possible TTVs from XO-6b, we looked at the system with NASA's TESS (@NASA_TESS) mission. \n\nTESS is perfect for this study because it has really good photometric and timing precision. \n\nMore on the timing verification from TESS: https://t.co/fmyIMPQCK6 2/8 https://t.co/8qLcDXeK3w"", 'The @NASA_TESS light curves of XO-6b were exquisite in precision allowing for us to characterize the system with much greater detail than ever before.  3/8 https://t.co/XTeqpqkY3G', 'We fit the individual and combined light curves with EXOMOP, a transit fitting code I developed in my PhD. All the fits individual fits were consistent with each other. \n\nMore details on code: https://t.co/P1dJrGCzS3\n 4/8 https://t.co/g9FkJPU7ac', 'The main result of our paper: \n- We find no evidence for TTVs: we can rule out TTVs &gt; 2.5 minutes at the 3σ level. \n- We rule out the previous claim of TTVs by 10σ \n5/8 https://t.co/cX5fQ4CEnG', 'The cause of the tension between our results &amp; those of Garai et al. (2020) is not clear but it may be due to unknown timing errors in their ground-based data. \n\n- A few of the smaller TTVs could be related to barycentric corrections, the larger ones must have other causes.\n\n6/8 https://t.co/QXXIeSKx9r', 'Careful absolute telescope clock calibrations are important to adequately schedule future atmospheric characterization observations on JWST, etc..\n\nOur study shows we need to be careful cause ground-based telescopes will definitely play a role (see https://t.co/0YheFgnuDd)\n7/8', ""In conclusion: \nOur findings highlight @NASA_TESS's capabilities for robust follow-up, and confirm that TTVs are rarely seen in hot Jupiters, unlike is the case with small planets. \n\nYou can find the paper free here: https://t.co/E1gDd0vzxm 8/8""]",20,09,2061