Daily Archives: April 22, 2014

The El Gordo Massive Galaxy Cluster 

This cluster has been nicknamed "El Gordo" (or, "the fat one" in Spanish) because of its gigantic mass.

Image Credit: NASA, ESA, J. Jee (UC Davis) et al.

It is bigger than a bread box. In fact, it is much bigger than all bread boxes put together. Galaxy cluster ACT-CL J0102-4915 is one of the largest and most massive objects known. Dubbed “El Gordo”, the seven billion light years (z = 0.87) distant galaxy cluster spans about seven million light years and holds the mass of a million billion Suns. The above image of El Gordo is a composite of a visible light image from the Hubble Space Telescope, an X-ray image from the Chandra Observatory showing the hot gas in pink, and a computer generated map showing the most probable distribution of dark matter in blue, computed from gravitational lens distortions of background galaxies. Almost all of the bright spots are galaxies. The blue dark matter distribution indicates that the cluster is in the middle stages of a collision between two large galaxy clusters. A careful inspection of the image will reveal a nearly vertical galaxy that appears unusually long. That galaxy is actually far in the background and has its image stretched by the gravitational lens action of the massive cluster.

NASA APOD 22-Apr-2014

Tarantula Nebula (NGC 2070)


The Tarantula Nebula (also known as 30 Doradus, or NGC 2070) is an H II region in the Large Magellanic Cloud (LMC).  The Tarantula Nebula has an apparent magnitude of 8. Considering its distance of about 49 kpc (160,000 light years), this is an extremely luminous non-stellar object. Its luminosity is so great that if it were as close to Earth as the Orion Nebula, the Tarantula Nebula would cast shadows. In fact, it is the most active starburst region known in theLocal Group of galaxies. It is also one of the largest such region in the Local Group with an estimated diameter of 200pc. The nebula resides on the leading edge of the LMC, where ram pressure stripping, and the compression of theinterstellar medium likely resulting from this, is at a maximum. At its core lies the compact star cluster R136 (approximate diameter 35 light years) that produces most of the energy that makes the nebula visible. The estimated mass of the cluster is 450,000 solar masses, suggesting it will likely become a globular cluster in the future.

In addition to R136, the Tarantula Nebula also contains an older star cluster – catalogued as Hodge 301 – with an age of 20–25 million years. The most massive stars of this cluster have already exploded in supernovae.

Imaging telescopes or lenses: Astro-Physics 152mm f/7.5 Starfire EDF
Imaging cameras: FLI ProLine Proline 16803
Mounts: Software Bisque Paramount MX
Guiding telescopes or lenses: Takahashi FS-60C
Guiding cameras: Starlight Xpress Superstar
Focal reducers: Astro-Physics AP 4.0″ Field Flattener
Software: PixInsight 1.8, Software Bisque TheSky6 Professional, FocusMax, Cyanogen Maxim DL Pro 5, Photoshop CS Photo Shop CS5, CCD Autopilot 5
Filters: Astrodon E-series LRGB Ha 5nm
Accessories: Sirius Dome
Dates: Jan. 10, 2014
Locations: Sydney Australia
Frames: 20×1200″
Integration: 6.7 hours

Author: David Nguyen

AstroPhotography of the day by SPONLI
22 April 2014