WD 1145+017 Observing Project

We seek the help of talented amateurs and undergraduates to help observe the White Dwarf WD 1145+017; the goal is to help determine the number and the properties of the multiple disintegrating planetesimals believed to be orbiting this white dwarf. All amateurs/undergraduates or other individuals who submit usable light curves will be included as co-authors in the resulting scientific publication. Further details on how to help out are below.

- Bryce Croll
For any questions please e-mail: wd1145.observing.project@gmail.com

Summary of the Multiple Disintegrating Planetesimals Orbiting WD 1145+017

The White Dwarf WD 1145+017 has been found to have multiple disintegrating planetesimals in short period (< 5 hour) orbits. The likely explanation for these multiple planetesimals is that a planet or asteroid has been tidally disrupted, and we are observing this system in the midst of being tidally disrupted. The main planetesimal appears to have a ~4.5 hour orbit, and we have already observed multiple transits causing drops in flux in excess of 40% of the stellar flux with transit durations as short as 5 minutes.
WD 1145 Transit Profile
Above: The duration of the transit events that we observe suggest that there are cometary tails trailing the disintegrating planetesimals in this system. Figure from Vanderburg et al. (2015).

Comet Profile
Above: A schematic of the trailing and leading cometary tails from the disintegrating planetesimal compared to the White Dwarf host size. Figure from Vanderburg et al. (2015).

Comet Profile
Above: Here is an artist's conception of what the main disintegrating planetesimal might look like. Image Credit: Mark Garlick.

Publications on WD 1145+017

Please see the resulting scientific publications for more information on this topic:
Vanderburg et al. (2015).
Croll et al. (submitted).
Xu et al. (2015).

Press Articles and Public Webpages on WD 1145+017

WD 1145 wikipedia article.
WD 1145 exoplanet.eu.
Phil Plait Bad Astronomy article on WD 1145

Observing Details

Amateurs, undergraduates and/or other individuals with approximately 14-inch telescopes or larger may be able to help us observe WD 1145+017. We are hoping to gather observers from around the world!
WD 1145 Amateur Observations
Above: Here is an example of amateur observations of WD 1145+017 using 14-inch and 16-inch telescopes by the amateurs Bruce Gary and Jerry Foote on UT 2015 Nov. 21st. Multiple decrements in flux are observed with depths up to 70% of the stellar flux!

Observers should:
  • Filter choice: use a broad optical filter, V-band or a similar optical filter.
  • For smaller telescopes (~16" or less), observers should avoid nights when the moon is full, or when the moon is close in the sky to WD 1145+017.
  • Aperture photometry should be performed on the data (using at least three reference stars) and the reduced light curves should be sent to the below e-mail address.
  • Please send your data in a text file using the following format:
    "Julian Date, Target Star Magnitude, Ref Star #1 Magnitude, Ref Star #2 Magnitude, Ref Star #3 Magnitude".
  • Please also include the name of the observers and the location of the observation (including the latitude and longitude of the observing site) in the body of the e-mail.
  • Please submit the light curves as attachments sent to the following e-mail address: wd1145.observing.project@gmail.com

    All individuals who submit light curves that are usable in the resulting scientific publication will be included as co-authors in the resulting scientific publication.

    Here are a few helpful links:
    WD 1145+017 Simbad Link.
    WD 1145+017 Finder Chart.

    Last Updated December 2015