Disk Detective

Planets form from vast clouds of gas, dust, and chunks of rock---clouds in the shape of disks, with stars in the center. We can find out where planets are forming and where planets probably remain today by searching for stars that are surrounded by these disks. Finding these disks, called “debris disks” or “YSO disks” depending on their age and gas content, has been a major quest of astronomers for the last three decades.

NASA’s WISE mission observed more than two billion sources, including galaxies, stars, nebulae, and asteroids--not to mention image artifacts and noise. Among these two billion sources are thousands of new disks waiting to be discovered.

Here at Disk Detective, you will help astronomers find these disks, homes for extrasolar planets. You'll examine images of disk candidates from NASA's WISE mission, and compare them with images from four different astronomical surveys: the SkyMapper Southern Sky Survey, the Pan-STARRS survey, the Two Micron All Sky Survey (2MASS), and the unWISE coadds of data from the WISE mission. Many of them will be junk, but every now and then you'll find a nice clean image, with no background objects or noise overwhelming the signal. And some of those will be new circumstellar disks!

This new version of the project is Disk Detective 2.1. It's a sequel to a citizen science project launched back in 2014 on the original Zooniverse Ouroboros platform. Disk Detective 1.0 discovered a whole new class of disks, called "Peter Pan Disks". Check out some more results from Disk Detective 1.0 here!

What are these "disks" we're trying to find?

A circumstellar disk is what it sounds like--it's a belt of material around a star. We typically expect debris disks to appear around main-sequence stars--stars that are in the main part of their life burning hydrogen. These are mostly made up of dust leftover from collisions of planetesimals--rocky bodies that might have eventually formed planets.

We also see disks around stars in their pre-main-sequence period--in the time when stars are actually forming. These disks are variously called Young Stellar Object (YSO) disks because they orbit pre-main sequence stars, or primordial disks because they are made up of material from the cloud that formed the star. These systems are very gas-rich. Some of these systems are known as protoplanetary disks, because they are the disks from which planets form!

To find these disks, we look for infrared excess--stars that have more infrared light than you would expect, which indicates the presence of material the gas and dust has warmed up. Here, we have selected a set of systems that have infrared excess--we are looking for your help to make sure that these systems actually look the way we expect them to (rather than looking like galaxies, or material from the gas and dust between stars).

Why use citizen science for this?

The Wide-field Infrared Survey Explorer (WISE) surveyed the full sky in four wavelengths of infrared light, allowing it to discover tens of thousands of circumstellar disks...in and among the other billion sources it found. However, WISE images can confuse a disk-hosting star with a galaxy, or nebulosity between the stars. The most effective way to detect these differences is by visual inspection of objects in multiple wavelengths, including optical and near-infrared light. To evaluate multiple thousands of objects efficiently, we've asked citizen scientists like YOU to help us out!

What happens next?

Once you all decide that an object is a good candidate, the science team springs into action! With your helpful comments on Talk, we investigate the good candidates in astronomical catalogs to weed out certain kinds of false positive that don't show up in our classification data. Then we collect follow-up observations to learn more! The best candidates after this advanced vetting and follow-up become new disk candidates in published professional journal articles!

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This material is based upon work supported by NASA under grant number NNH14ZDA001N-XRP. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration (NASA).

Image Credits:
This project makes use of data products from the Wide-field Infrared Survey Explorer (WISE), the Two Micron All Sky Survey (2MASS), the Panoramic Survey Telescope and Rapid Response System (PAN-STARRS) DR1, and the Skymapper Southern Sky Survey.

The Wide-field Infrared Survey Explorer (WISE) is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, and NEOWISE, which is a project of the Jet Propulsion Laboratory/California Institute of Technology. WISE and NEOWISE are funded by the National Aeronautics and Space Administration.

The Two Micron All Sky Survey is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.

The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation.

The national facility capability for SkyMapper has been funded through ARC LIEF grant LE130100104 from the Australian Research Council, awarded to the University of Sydney, the Australian National University, Swinburne University of Technology, the University of Queensland, the University of Western Australia, the University of Melbourne, Curtin University of Technology, Monash University and the Australian Astronomical Observatory. SkyMapper is owned and operated by The Australian National University's Research School of Astronomy and Astrophysics. The survey data were processed and provided by the SkyMapper Team at ANU. The SkyMapper node of the All-Sky Virtual Observatory (ASVO) is hosted at the National Computational Infrastructure (NCI). Development and support the SkyMapper node of the ASVO has been funded in part by Astronomy Australia Limited (AAL) and the Australian Government through the Commonwealth's Education Investment Fund (EIF) and National Collaborative Research Infrastructure Strategy (NCRIS), particularly the National eResearch Collaboration Tools and Resources (NeCTAR) and the Australian National Data Service Projects (ANDS).

This research has made use of the NASA/ IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.