FAQ
Where does the data come from?
The images were taken by Vera C. Rubin Observatory’s Simonyi Survey Telescope in Chile using the LSST Camera as part of the Rubin Data Preview 2 (DP2) release. NSF-DOE Vera C. Rubin Observatory is funded by the US National Science Foundation and the US Department of Energy’s Office of Science. More information at Rubin Observatory.
DP2 contains deep co-add images allowing you to see extremely faint and diffuse objects that have likely not been seen before. For more information on the Rubin DP2 data release, please see: LSST DP2. (NSF-DOE Vera C. Rubin Observatory (2026); The Vera C. Rubin Observatory Data Preview 2 )
Where can I see more examples?
All the relevant examples you need can be found in the Field Guide under our Classify tab, which can be opened through the pop-up tab on the top right side of your screen. You can also read more in-depth articles about blue blobs, diffuse galaxies, and other research-related topics from the external links we posted on our project's homepage. Also, for examples of very faint diffuse galaxies, please visit our Results tab.
What happens if I provide an incorrect response to a question?
Multiple people must review an image set before it is considered classified, so one incorrect or mis-clicked classification will not affect the overall accuracy of our data. We're interested about how the majority of people have classified an image set.
Why are volunteers needed to do this instead of computers?
When it comes to identifying extreme galaxies, citizen scientists are more accurate than computers for a number of reasons. For example, blue blobs are all very rare and faint in appearance, and can take on a variety of morphological shapes, which is difficult for a computer to recognize. For diffuse galaxies, computer algorithms do exist that can identify them, but in order to verify how reliable these algorithms are we need to also identify these objects by eye. We can achieve this by evaluating imaging surveys of nearby galaxy clusters like the Virgo Cluster, however these typically consist of far too many images for any one person to go through, so we need a team of willing citizen scientists to help us check each one for blue blobs and diffuse galaxies! If you would like to discover more about the impact of citizen science on our last project, go check out our Diffuse Dwarfs found in Fornax paper located at the bottom of our home page!
Does it matter which image I draw a box/circle on?
The box/circle you draw will show up on all three images after you draw it, so it doesn't matter which image you choose to draw on. However, it's easiest to pick one of the two optical images to draw on rather than the UV image, since many objects don't show up on the UV images, so that you don't draw a box/circle around the wrong thing!
Commonly Used Terms
Diffuse Galaxies - Objects with the same number of stars as dwarf galaxies (roughly a million to a billion stars) but an effective radius comparable to the Milky Way. There is a low density of stars spread across the entire volume of the galaxy.
Blue Blobs - Stellar systems with highly irregular and clumpy shapes that consist of young blue stars.
Nucleated - A visible bright core at the center of the diffuse dwarf.
Co-add images - An image created by stacking many individual images of the same patch of sky.
Visits - A visit is a single observation of ~ten-square-degrees of sky through a given filter.
LSST DP1/ DP2 - LSST will acquire images as pairs of back to back, 15 second exposures. Data previews are a series of data releases that progressively increase in size and complexity as a ramp up to the first annual data release. DP1 is based on images from the seven-week on-sky campaign with the LSSTComCam and covers seven small fields that offers small versions of most image and catalog types to help prepare scientific analyses and workflows. DP2 contains deep coadded images and all catalogs will be available. For now, data from DP2 of the region around M49 in the Virgo cluster is being used by the Rubin: Blobs and Blurs project, although we intend to expand across more of the sky soon.