Dragonfly 44 is 99.99% dark matter

• by Budgieye moderator

  the galaxy, named Dragonfly 44, had been missed by astronomers for
  decades because it is very dim.... However, only one hundredth of one
  percent of that is in the form of stars and "normal" matter; the other
  99.99 percent is in the form of dark matter. The Milky Way has more than a hundred times more stars than Dragonfly 44.

  http://www.keckobservatory.org/recent/entry/scientists_discover_massive_galaxy_made_of_99.99_percent_dark_matter

  

  http://www.keckobservatory.org/images/made/images/press_images/fig1_800_561.png

  ---

  

  http://skyserver.sdss.org/dr12/SkyserverWS/ImgCutout/getjpeg?TaskName=Skyserver.Explore.Image&ra=195.242403449745&dec=26.976691276558&scale=0.2&width=200&height=200&opt=

  

  http://skyserver.sdss.org/dr12/SkyserverWS/ImgCutout/getjpeg?TaskName=Skyserver.Chart.Image&ra=195.242403449745&dec=26.976691276558&width=512&height=512&scale=0.4

  http://skyserver.sdss.org/dr12/en/tools/explore/Summary.aspx?id=1237667442975048508

  http://cas.sdss.org/dr7/en/tools/explore/obj.asp?id=587741721750143747

  seen and posted in Galaxy Zoo Forum by by Jules in Re: Dwarf Galaxies
  « Reply #79 on: September 09, 2007, 02:25:02 pm »
  http://www.galaxyzooforum.org/index.php?topic=4913.msg47236#msg47236

  Posted December 16, 2016 9:25 AM

• by zutopian

  Please be informed about following new paper.:

  Future Prospects: Deep Imaging of Galaxy Outskirts using Telescopes Large and Small
  Roberto Abraham, Pieter van Dokkum, Charlie Conroy, Allison Merritt, Jielai Zhang, Deborah Lokhorst, Shany Danieli, Lamiya Mowla

  The Universe is almost totally unexplored at low surface brightness levels. In spite of great progress in the construction of large telescopes and improvements in the sensitivity of detectors, the limiting surface brightness of imaging observations has remained static for about forty years. Recent technical advances have at last begun to erode the barriers preventing progress. In this Chapter we describe the technical challenges to low surface brightness imaging, describe some solutions, and highlight some relevant observations that have been undertaken recently with both large and small telescopes. Our main focus will be on discoveries made with the Dragonfly Telephoto Array (Dragonfly), which is a new telescope concept designed to probe the Universe down to hitherto unprecedented low surface brightness levels. We conclude by arguing that these discoveries are probably only scratching the surface of interesting phenomena that are observable when the Universe is explored at low surface brightness levels.

  https://arxiv.org/abs/1612.06415
  (Submitted on 19 Dec 2016)

  Posted December 23, 2016 2:00 PM