Marengo (Iowa State) is himself well represented in the archives.
Image: Montage of flux time series for KIC 8462852 showing different portions of the 4-year Kepler observations with different vertical scalings.
Last week I mentioned that I wanted to get into Massimo Marengo’s new paper on KIC 8462852, the interesting star that, when studied by the Kepler instrument, revealed an intriguing light curve.
I’ve written this object up numerous times now, so if you’re coming into the discussion for the first time, plug KIC 8462852 into the archive search engine to get up to speed.
What we lacked from Tabetha Boyajian’s earlier paper (and it was Boyajian, working with the Planet Hunters group, that brought KIC 8462 to our attention) was data about infrared wavelengths after the WISE mission finished its work.
That was a significant omission, because the WISE data on the star were taken in 2010, while the first events Kepler flagged at KIC 8462 occurred in March of 2011, with a long series of events beginning in February of 2013 and lasting sixty days.
All these scenarios would produce very large amount of dust dispersed along the orbits of the debris, resulting in more mid-IR emission than what can be inferred from the optical depth of the dust seen passing along our line of sight to the star.Our limit (two times lower than the limit based on WISE data) further reduces the odds for these scenarios.Alternatively, if significant quantity of dust is present, it must be located at large distance from the star.As noted by B15 [this is the Boyajian paper], this makes the scenarios very unlikely in which the dimming events are caused by a catastrophic collision in KIC 8462852 asteroid belt, a giant impact disrupting a planet in the system, or a population of dust-enshrouded planetesimals.In the new paper, Marengo moves the ball forward in our quest to understand why the star I’ll abbreviate as KIC 8462 poses such problems.The F3-class star doesn’t give us the infrared signature we’d expect from a debris disk, yet the light curves we see suggest objects of various sizes (and shapes) transiting across its surface.