Jason Wright @Astro_WrightReplying to @zero132132 and 3 othersRight. We will make the data truly public eventually, somehow. Right now it's not mine to give away, and it's not in a final form we trust.
Tabetha Boyajian @tsboyajianLooking forward to what happens tonight with #tabbysstar . @kickstarter backers expect a full update tomorrow!
1hJason Wright @Astro_WrightAstro hive-mind:How do I get an ephemeris for @NASAKepler from @NASAJPL Horizons? I want x,y,z in barycentric frame.Jason Wright @Astro_WrightReplying to @Astro_Wright and 2 othersI tried getting distance, RA, DEC from vantage of SSB (site @0) but I get "Barycentric OBSERVER table disallowed -- consider body-center 10"
Can anyone estimate why Jason Wright would be after this info?Quote1hJason Wright @Astro_WrightAstro hive-mind:How do I get an ephemeris for @NASAKepler from @NASAJPL Horizons? I want x,y,z in barycentric frame.Jason Wright @Astro_WrightReplying to @Astro_Wright and 2 othersI tried getting distance, RA, DEC from vantage of SSB (site @0) but I get "Barycentric OBSERVER table disallowed -- consider body-center 10"https://mobile.twitter.com/Astro_Wright/status/866995929236287488
Quote from: Star One on 05/23/2017 02:05 pmCan anyone estimate why Jason Wright would be after this info?Quote1hJason Wright @Astro_WrightAstro hive-mind:How do I get an ephemeris for @NASAKepler from @NASAJPL Horizons? I want x,y,z in barycentric frame.Jason Wright @Astro_WrightReplying to @Astro_Wright and 2 othersI tried getting distance, RA, DEC from vantage of SSB (site @0) but I get "Barycentric OBSERVER table disallowed -- consider body-center 10"https://mobile.twitter.com/Astro_Wright/status/866995929236287488When you're looking at transits/occultations/etc., the time the observer sees the event depends on the location of the observer, because the light travel time from the event itself to the observer depends on the position of the observer. Suppose one observer on Earth was looking at, oh, say an extrasolar planet transiting its star. That observer would probably measure different ingress/egress times than would, say, the Kepler satellite, because the Earth and Kepler are most likely at different distances from the event. For occultations/transits/etc., I believe the general practice is to correct times to heliocentric julian date, though perhaps they're using the solar system barycenter (which is what I suspect the "SSB" means). So it would seem somebody's looking to transform the time of an observation made by Kepler, to the time the light would have been seen by an observer at the solar system barycenter, or perhaps vice versa.
For occultations/transits/etc., I believe the general practice is to correct times to heliocentric julian date, though perhaps they're using the solar system barycenter (which is what I suspect the "SSB" means). So it would seem somebody's looking to transform the time of an observation made by Kepler, to the time the light would have been seen by an observer at the solar system barycenter, or perhaps vice versa.
I may have missed it, but has the star started brightening again yet?
Tabetha Boyajian @tsboyajianReplying to @Apnoespock and @kickstarterwe have a few holes, and of course weather gets in the way too, but we have been fortunate over that
Quote from: JasonAW3 on 05/23/2017 06:07 pmI may have missed it, but has the star started brightening again yet?It's back to normal at the moment.QuoteTabetha Boyajian @tsboyajianReplying to @Apnoespock and @kickstarterwe have a few holes, and of course weather gets in the way too, but we have been fortunate over thathttps://mobile.twitter.com/tsboyajian/status/867060889056403456
Quote from: Star One on 05/23/2017 06:44 pmQuote from: JasonAW3 on 05/23/2017 06:07 pmI may have missed it, but has the star started brightening again yet?It's back to normal at the moment.QuoteTabetha Boyajian @tsboyajianReplying to @Apnoespock and @kickstarterwe have a few holes, and of course weather gets in the way too, but we have been fortunate over thathttps://mobile.twitter.com/tsboyajian/status/867060889056403456So I guesx that they don't hve the light curve and duration figures compiled just yet.
KIC 8462852 stood out among more than 100,000 stars in the Kepler catalogue because of the strange features of its light curve: a wide and asymmetric dimming taking up to 15 per cent of the total light, together with a period of multiple, narrow dimmings happening approximately 700 days later. Several models have been proposed to account for this abnormal behaviour, most of which require either unlikely causes or a finely-tuned timing. We aim at offering a relatively natural solution, invoking only phenomena that have been previously observed, although perhaps in larger or more massive versions. We model the system using a large, ringed body whose transit produces the first dimming and a swarm of Trojan objects sharing its orbit that causes the second period of multiple dimmings. The resulting orbital period is T≈12 years, with a semi-major axis a≈6 au. In this context the recent observation of a minor dimming can be explained as a secondary eclipse produced by the passage of the planet behind the star. Our model allows us to make two straightforward predictions: we expect the passage of a new swarm of Trojans in front of the star starting during the early months of 2021, and a new transit of the main object during the first half of 2023.
Since we're speculating, what would it look like if an icy giant gas planet regularly gets too close to a larger gas giant in orbit?
New paper KIC 8462852: Will the Trojans return in 2021? Fernando J. Ballesteros, Pablo Arnalte-Mur, Alberto Fernandez-Soto, Vicent J. Martinez (submitted, not yet reviewed / accepted)QuoteKIC 8462852 stood out among more than 100,000 stars in the Kepler catalogue because of the strange features of its light curve: a wide and asymmetric dimming taking up to 15 per cent of the total light, together with a period of multiple, narrow dimmings happening approximately 700 days later. Several models have been proposed to account for this abnormal behaviour, most of which require either unlikely causes or a finely-tuned timing. We aim at offering a relatively natural solution, invoking only phenomena that have been previously observed, although perhaps in larger or more massive versions. We model the system using a large, ringed body whose transit produces the first dimming and a swarm of Trojan objects sharing its orbit that causes the second period of multiple dimmings. The resulting orbital period is T≈12 years, with a semi-major axis a≈6 au. In this context the recent observation of a minor dimming can be explained as a secondary eclipse produced by the passage of the planet behind the star. Our model allows us to make two straightforward predictions: we expect the passage of a new swarm of Trojans in front of the star starting during the early months of 2021, and a new transit of the main object during the first half of 2023.Trojans are a clever way to get a ~700 day period without having the dust warm enough to exceed observational limits, but the trojan clouds need to be extremely massive and/or dusty. The larger orbit also greatly relaxes constraints from radial velocity. The authors specifically note that it doesn't address the long term dimming. They suggest the most recent dip is compatible with a secondary eclipse of the planet.My overall impression is interesting and not totally implausible, but not really satisfying.
Quote from: JasonAW3 on 05/23/2017 06:07 pmI may have missed it, but has the star started brightening again yet?It's back to normal at the moment.
My overall impression is interesting and not totally implausible, but not really satisfying.
Sounds like they are working on it with the Kickstart supporters first in line for an update.
Be interesting to see if it now goes into a vast dip because the best fit that Jason Wright was suggesting for this dip, last time I saw from the Kepler data was just before one of these.
Edit2: perhaps we *are* seeing phase modulation. See figure 3 of Ben Montet's paper (https://arxiv.org/abs/1608.01316).