Light Curves

On Light Curves

We have been promoting the transient dimming sky as a pretty exciting setting for discovery. Someday scientists will actively search for dimming objects, rather than having them primarily found serendipitously in archives or by citizen scientists (with their eyeballs) as is true for Tabby's star (aka Boyagian's star) and Megan's dippers. Eclipsing disks are fantastic as they can give information on milli AU scales in a planet or satellite forming environment. With dippers (low mass stars) we favor a unified magnetospheric lifting and truncation scenario. Quasiperiodic dippers and periodic eclipsing disks allow study of the composition of circumstellar material through spectroscopy.

Dippers in Upper Sco and Rho Ophiucus and dusty corotating structures at the edge of a magnetospherically truncated accretion disk. A unified model explaining (with orientation) why so many young stars show this phenomena. Dippers and Dusty Disks Edges: A Unified Model (arxiv) and part of Eva's thesis, (ADS) Dippers and dusty disc edges: new diagnostics and comparison to model predictions
Eva's thesis papers: On Taby's star! KIC 8462852: Transit of a Large Comet Family (arxiv), ADS
How to find evidence of a circumbinary disk in a binary even if is not an eclipsing binary. arxiv , Infrared Variability from Circumbinary Disc Temperature Modulations

Why transient searches should look for objects that fade, dim or disappear altogether, Real time triggering on Dimming events. Currently transient identification software only triggers on astronomical objects that get brighter.
Erin's paper: Modeling Transiting Circumstellar Disks: Characterizing the Newly Discovered Eclipsing Disk System OGLE LMC-ECL-11893 (ADS)
A search for dimming events in 40000 stars in the 2Mass calibration database. A search for red dimming events surprisingly turns up low luminosity active galaxies and young stellar objects. Note: I think the galaxies are found because of seeing variations rather than because the light curves vary (figured this out after paper was published)! Variability in the 2MASS Calibration Fields: A Search for Transient Obscuration Events, ADS
How to find eclipsing disks (and other interesting objects) in databases of eclipsing binary curve light curves. (Meng's paper! You can use the magnitude distribution in the transit or measurements of asymmetry in eclipse!) The fraction of young eclipsing binaries that host discs, ADS We expected to find disks in widely separated and young binary systems, (This is because disks don't survive for long and there isn't much room in a tight binary for a disk and dust sublimates close to a star). However this survey, using the OGLEIII LMC eclipsing binary sample, finds a 150 Myr old disk (discovered by Subo Dong) with a 454 day period, and a disk candiate in a system with a B star and perhaps some kind of star or compact object in a 13.3 day period system. The asymmetric search found an object with transit timing variations and two large stars in an elliptical orbit.
On eclipsing circumplanetary and circumsecondary disks -- J1407's eclipse was discovered by Eric Mamajek and Marc Pecaut. Planetary Construction Zones in Occultation: Eclipses by Circumsecondary and Circumplanetary Disks and a Candidate Long and Deep Eclipse of a Pre-Main Sequence Star in Sco-Cen (ADS).