Disk Detective Talk

What exactly are we doing here?

  • planetaryscience by planetaryscience

    So, as the name, blog post, and description on the main website implies, you are looking for protoplanetary disks around distant stars, and using the new approach of citizen science to do it, but once you start through the data, you ask yourself "what are we looking for exactly?" as it becomes clear that they're not asking you to find rings around the stars.

    So what are we looking for? Are we simply looking for good candidates for a more in-depth search, if so, will we be involved in this new search?

    My main question is, what is our role in this and what is your goal and future examinations of our classifications?

    -Planetaryscience

    Posted

  • lrebull by lrebull scientist, translator, admin

    Some of the answers to your questions can be found, from the 'menu' on the top right of any classification screen, under the 'science' link. Others can be found on the Disk Detective blog.

    You're absolutely right that these things are so far away as to not be resolved into rings around the stars in these images. We are looking at the combined light of the star+disk (or the galaxy). That combined light, if it is a star+disk, will appear to have "more IR than you expect to see" if it were a plain (disk-free star).

    The reason we are looking at the images is that the computer can be fooled far more easily than the human eye can. The difficulty comes in how we went about culling the entire sky down to these sources. We can find things that have the right colors to be star formation. In some cases, though, this color selection is finding star formation .. but in another galaxy, not a single disk around a single star in our Galaxy. There's no way to tell that easily, automatically, without looking at the images. In other cases, the computer just screwed up and assigned fluxes to the wrong source. That's another case where we can only figure out what's going on if we look at the images. In still other cases, there are artifacts on the images, and so the computer has been fooled into assigning the wrong flux to a given object that might really be there, just subject to these artifacts (like a diffraction spike). That's yet another case where we can only figure it out if we look at the images.

    So, yes, we will take the subset of objects you all find to be good sources, and go get additional data on them to find out what they are, if they really are stars with disks. We'll get additional photometry in some cases, spectroscopy in others. It depends on what you find.

    Posted

  • abans by abans scientist, moderator

    Great question!

    Indeed the name "Disk Detective" implies we are looking for disk and ring shaped objects around young stars... and we are! Problem is, in these images, those shapes won't be resolved. In these data sets we only see a single point of light that is coming from the star that is enshrouded by that ring/disk of dust so we expect to see a single round point of light but for it to also be bright in the WISE bands (which cover the wavelengths where warm dust radiates at).

    Cool thing is, once we find some debris disk or YSO disk candidates, they could become targets for other telescopes, like the Hubble, which could tell us much more of the structure/shape of the disk. So you are helping us find a whole bunch of new forming or remnant solar systems, which will make great targets for additional existing and future studies.

    I'll get some of the other scientists on board with this question too!

    -Alissa

    Posted

  • planetaryscience by planetaryscience

    After reading, I found the 'science' explanation for it, and found it interesting. However, it still leaves the question: After finding good candidates, will the project continue into the direct imaging of debris disks with us still being involved?

    I'd personally like to remain involved in seeing the disks after this candidate-work is done, but I'd expect that if you're using multi-million-dollar observatories to image them, there isn't much you can hand over to a 12-year-old complete stranger, no matter how careful they'd promise to be. ( 😛 )

    Is there anything beyond looking at stars that I or other people could do? I've been interested in Exoplanets and the solar system my whole life, spending nearly every waking moment thinking of one day seeing other worlds, orbiting around other stars...

    Posted

  • lrebull by lrebull scientist, translator, admin

    There are lots and lots of places to get your hands on real data. Citizen science is the best way to start but is by no means the only way to get involved. This is my own list of projects that work with real data - I assembled this list for another project I work with, and the projects on this list span a very wide range of levels in terms of age, whether you have to be part of a class or can do it on your own, whether you need your own observatory or not, whether you have to work mostly on your own or can get a lot of help from the project, whether you have to be in a specific city or country or not, etc., etc., So you will need to go through this list and see if you can find something that suits your needs.
    http://nitarp.ipac.caltech.edu/page/other_epo_programs

    Posted

  • marckuchner by marckuchner scientist, admin

    We're planning to involve you and other top Disk Detectives in the next stages of the search best we can. For now, we're still getting to know y'all and working on handling this classification data--and that might take a few months. But stay tuned for more!

    In the meantime, you can help by checking out the "References" on SIMBAD for your favorite candidates to see what you can learn about them from the literature. Before we discover new disks, we should be rediscovering ones that are already know--and you'll be able to figure that out from the papers mentioned on SIMBAD. That's important because it will help us build confidence in our search method!

    It's wonderful to hear your enthusiasm, and great to have you as a collaborator.

    Posted

  • TED91 by TED91 moderator

    I don't know where else to put it so I just ask here.

    Does anyone know how many "good candidates" we should expect? (approximately in percent). I am just curious.

    Posted

  • abans by abans scientist, moderator

    On the top of my head, I believe we expect/aim to find ballpark 400 never- before-discovered debris disks systems. Probably we expect there to be quite a bit more good candidates, because some will be false positives and others will be known systems. I guess the percentage depends somewhat on how many "false positives" look good by our selection criteria.. so I'm not sure exactly.

    I'll check with some of my colleagues and get back to you!

    Posted

  • JasonJason by JasonJason

    What is the point of checking something like AWI000010f and the only option to pick is Good candidate, but if you select discuss on talk and check simbad you find it is 2MASS J15510051+0012058 -- Seyfert 1 Galaxy. Then Good candidate is not the best option because it is not a star. So what do you select and choose? The selection system seems to be backwards, why not check simbad first and then it automatically may get ruled out if it is not a star.

    Posted

  • lrebull by lrebull scientist, translator, admin

    Because SIMBAD isn't always right. See this blog post for more discussion: http://blog.diskdetective.org/2014/02/02/the-power-and-danger-of-simbad/ In brief, SIMBAD is fallible; even if there is stuff in there, it might not be categorized correctly.

    The selection stuff that we're asking you to do as the main component of Disk Detective is meant to reflect what you are seeing in the images. The SED and SIMBAD are kind of the "next steps" - meaning, OK, if the images look ok, does the SED look ok, and what else might be known about this object? It's good to note that SIMBAD thinks it's a galaxy in the notes about the object. But the next steps one could take is to find the references that SIMBAD lists for this thing - does it really appear in the papers SIMBAD lists? Is its categorization as a Seyfert something that has been confirmed by spectra or just guessed based on properties at other wavelengths? For example, there is a particularly pernicious target I've worked on before that is a young star that is really close but not quite superimposed on a background galaxy. That object appears in both young star and extra galactic papers, because sometimes people (accidentally or intentionally) got a spectrum of the young star, and sometimes they (accidentally or intentionally) got a spectrum of the galaxy. The literature still gets confused about this source - sometimes it appears with the wrong name or tied to data from the wrong source. So to really sort it out, you have to go back all the way to the papers SIMBAD cites, and then sort out what those papers were claiming, and if they got it right. It's not always as clear-cut as "well, SIMBAD says it's a galaxy so we should dump it." It takes a little more digging!

    Posted

  • lrebull by lrebull scientist, translator, admin

    Here are several more words on why we're not seeing rings in the Disk Detective data. http://blog.diskdetective.org/2014/02/20/thats-no-moon/

    Posted

  • onetimegolfer by onetimegolfer

    OK first I think I'm getting better at this (read and saved a ring binder of explanations on the subject) Criteria in the spring observation is not exactly the same as the fall follow-up: If the distance has to be < 200 parsecs and proper motion > 30arcsec/year because of Whipple's capabilities I don't see but around 5 goodcandidates for spring follow-up; am I right on this point?

    Posted

  • lrebull by lrebull scientist, translator, admin

    What? Distance should be in parsecs or light years. 30 arcseconds/year would be a very large proper motion (motion across the sky), not distance to the object. We currently have more than 100 viable targets for spring.

    Posted