What Are Yellowballs?

• by ttfnrob admin, scientist

  I asked science team member Matt Povich about the #yellowball objects and he said this that they are most likely extremely bright compact or ultracompact HII regions. They look bright and yellow because they saturate the image in the 8 and 24 µm. You can think of them as small, very luminous bubbles.

  Posted December 9, 2010 3:29 PM

• by ttfnrob admin, scientist

  By the way - if you haven't seen this type of page before - it's a discussion about a keyword set - the images on the right will keep updating when you tag things as containing a #yellowball.

  Posted December 9, 2010 3:31 PM

• by kirbyjp in response to ttfnrob's comment.

  ttfnrob, are we to circle the yellowball objects? If so, they seem to be solid, round items, should we use the "small bubble" annotation, or use the circle drawing tool to trace the outer limit of just the yellow ball?

  Posted December 9, 2010 7:44 PM

• by ttfnrob admin, scientist in response to kirbyjp's comment.

  kirbyjp - no don't draw them as bubbles - mark them as 'green knots' for now. We may add a specific item in the list for them.

  Posted December 10, 2010 9:28 AM

• by katieofoz

  Thanks, I had been marking them as green knots but thought they might be small bubbles

  Posted December 10, 2010 12:32 PM

• by PattyD

  So how do I tag something as an artefact?

  Posted December 11, 2010 9:55 PM

• by jules moderator in response to PattyD's comment.

  Hi PattyD,
  If you click "Discuss" - you can then put #artefact in the comments box. Your picture will then show up on search using "artefact."

  Posted December 13, 2010 9:20 PM

• by PattyD

  At last, enlightenment. I may get the hang of this after all.

  Posted December 23, 2010 11:16 AM

• by kgwaite

  thanks for putting that up. I've been seeing a lot of those but didn't know what they were.

  Posted January 11, 2011 8:30 PM

• by gwolfchase scientist

  According to my postdoc, Milky Way Project science team member Kim Arvidsson, yellowballs actually represent different categories of objects. Kim cross-checked the list of current yellowball identifications with various catalogs, so if anyone has a particular favorite, we may be able to tell you some more about it (not all yellowballs could be identified with catalog objects). Adler MWP team members are particularly interested in distinguishing regions forming really massive stars from those forming less massive stars, in order to learn more about the conditions under which massive stars form.

  Posted February 23, 2011 7:14 PM

• by Gaumondd

  Arte the bright red speres foreground stars?

  Posted April 19, 2011 6:03 PM

• by ttfnrob admin, scientist

  This has all now resulted in a paper. You can get the details here on the MWP blog: http://blog.milkywayproject.org/2015/01/28/a-new-paper-all-about-yellowballs/

  Thanks to all who helped make this possible.

  Posted January 28, 2015 3:21 PM