This is a photo taken just before sunrise on the morning of April 4, 2015 showing the total eclipse of the full moon that marked the start of the Easter season for 2015. This is the third of four total lunar eclipses that will be visible during the two year period that began with an Easter eclipse in 2014. It is a relatively rare occurrence to have two consecutive total eclipses of the full moon that precedes Easter. Photo credit: Dr. Michael D. Joner
This is a photo taken in the early evening of September 27, 2015 showing the full moon rising over Y Mountain. This is the last of four total lunar eclipses that were visible during the two year period that began with an Easter eclipse in 2014. This cycle of four total lunar eclipses is known as a tetrad. It is relatively rare to have a cycle such as this coincide with religious holidays such as Easter and so these eclipses were frequently associated with "end of the world" speculation. Photo credit: Dr. Michael D. Joner
This image was taken with a DSLR at the West Mountain Observatory about an hour before sunrise on 4 April 2015 by Dr. Michael Joner. Near the center of the constellation of Sagittarius is a bright star that was not seen just a few weeks earlier. This new naked eye star was discovered on March 15, 2015 in survey images taken in Australia. Spectroscopic observations secured the next night confirmed that this is a classical nova, and it was named Nova Sagittarii 2015 No. 2. A classical nova is a binary system where a white-dwarf star collects gas from a close companion star so that the material flows onto the surface of the white dwarf. As the material builds up on the white dwarf, the bottom layers become hot and dense so that they ignite in a runaway hydrogen-fusion reaction which blasts the shell off into space and causes a temporary increase in luminosity by a factor of 50,000 or more. Unlike supernovae that destroy the progenitor star, novae are recurrent events. It is estimated that about 40 novae occur in the Milky Way each year, and about ten of these are visible from Earth. This nova is expected to fade away over the next month or two and return to a luminosity close to what it was before this outburst.
This image was secured just after the end of evening twilight on a clear April night from the West Mountain Observatory. The view is looking west past the domes housing the two smaller research telescopes at the observatory. The thin crescent Moon is also illuminated by reflected light from the Earth that is known as earthshine. Higher in the sky, the bright 'star' is actually the planet Venus. In between the two, the 'V' shaped group of stars in the constellation of Taurus is in reality the nearby open cluster known as the Hyades. Photo credit: Dr. Michael D. Joner
This image was secured during the installation of the 0.9-m telescope at the BYU West Mountain Observatory. Data for this image is from August 27, 2009. This was the first night that a CCD had been mounted on the telescope so that imaging was possible. This 'First Light' image shows the globular cluster known as M15 in the constellation of Pegasus. The distance to this cluster is more than 33,000 light years and yet individual stars are easily resolved all through the cluster. Globular cluster stars have an extremely low abundance of heavy elements as compared to stars found in the solar neighborhood and represent the oldest population of stars known in the Galaxy. It is interesting to note the many cool red giant stars that are visible in the cluster as well as a large number of evolved horizontal branch stars that are blue in color. Many of the horizontal branch stars are known to be RR Lyrae variable stars that are useful as distance indicators since it is possible to determine their luminosity and compare that value to their apparent magnitude as measured from the observed images. The color image processing for this picture is the work of renowned image processing guru, Dr. Rob Gendler.
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Brian Anderson et al. recently published an article titled "Depth profile of a time-reversal focus in an elastic solid" in Ultrasonics. Click on the image above to read it.
The Rise and Fall of Supernova 2015F : Sit back and watch a star explode. The actual supernova occurred back when dinosaurs roamed the Earth, but images of the spectacular event began arriving last year....
This photograph and Description come from NASA's Astronomy Picture of the Day web site.