Galaxy Zoo Talk


  • ksrivatsan by ksrivatsan

    Hello everyone,

    This one is interesting- it's very blue, bluer than most ellipticals, but it doesn't look like a spiral (though there are some "arm" patterns...) Could it be lenticular?


  • JeanTate by JeanTate in response to ksrivatsan's comment.

    I think I can just make out a faint arm or two, but yes, it's otherwise a lenticular.

    Here's what it looks like in SDSS (it's SDSS J150249.94+023131.7):

    enter image description here

    The SDSS spectrum says "STARFORMING", and the strong emission lines indicate why. So it's very unlikely to be an elliptical!

    Also, if you want to dig deeper, you can click on the PhotoObj link (in the left-hand panel of the SDSS Explore page), and scroll down to the five fracDeV parameters; if the _g and _r ones are < 0.5, then the galaxy is very likely not an elliptical (doesn't work the other way; there are thousands of spirals with values >0.5 😦). Interested in understanding why this is a good indicator? Just ask!

    Hope this helps, and happy hunting! 😃