Old Astronomy News

Old Astronomy News

Briefs

More x-ray burst sources have been discovered by the SAS-3 and ANS astronomical satellites. First discovered in December 1975 in the region of a globular cluster in the constellation Sagittarius, two more have been located near the galactic core and two have been found in the constellation Scorpius. One of the bursters, as they are sometimes called, has a burst strength about equal to that of the Crab nebula.

Galaxy. Artwork by Marc Paternostro

Walter Lewin, head of the Massachusetts Institute of Technology team that first discovered the sources, believes the bursters are binaries with a neutron star component. Because the collapsed star has a strong magnetic field, material flowing from the normal star toward its companion builds up until the field non longer can contain it. Matter that pours through and rapidly heats up, emitting bursts of x-rays.

The Ring Nebula. Photograph by NASA. Image of public domain

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The validity of the inverse square law at laboratory distances for gravity has been questioned by an Eastern Washington State College scientist. In a recent issue of Nature, D. R. Long stated that accurate determinations of the gravitational constant (G) suggests that the value of G increases as the separation between attracting masses increases. He found a discrepancy of 0.37 percent in the value of G.

The Planet Venus. Source of the photograph: Space.com

The inverse-square law has been verified by astronomers for planetary motions, although one researcher demonstrated that a slight modification in the law’s form could explain slight anomalies in Mercury’s motion. Long said, however, that what might be true at astronomical distances might not be true at laboratory distances.

The Crab Nebula. Photograph by NASA. Image of public domain

Long said his experimental results are consistent with past laboratory measurements of G. Convincing fellow scientists may not be so easy. The scientists stressed, however, that the important thing is to get someone to duplicate the experiment to see if his results are reliable.

The Rings of Saturn. Source of the photograph: lupuvictor.blogspot.com

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A recent cosmological theory states that galaxies, in addition to being gathered into groups and clusters, are also bound together in huge super-galaxies. Those who support this theory cite the apparent distribution of galaxies along a “super-galactic equator” – somewhat similar to the arrangement of nearby stars into the band of the Milky Way – and consider this apparent clustering as evidence of a huge “spiral arm” type of arrangement. The theory`s opponent state that this arrangement is an illusion produced by the presence of the stars and dust of the Milky Way, which blocks galaxies behind it from our sight. The diagram at right shows the arrangement of galaxies out to about 50 million light-years; the super-galactic equator by the red line.

Jupiter’s Cloud Belts Source of the photograph: cnn.com

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Galaxies more distant than 50 million light-years. The theory of the super-galaxy states that the apparent clustering of galaxy clusters shows that they are arranged in large flattened systems analogous to normal spiral galaxies. One of the largest groups is the Coma Virgo cluster, one of the largest clusters of galaxies known. Most of the theory`s proponents state that there are a large number of these super-galaxies: some take the apparent evidence still further and hypothesize a universe of galaxies arranged in one enormous system that contains our entire universe. Those who accept the big bang theory of the universe’s origins sometimes offer it as explanation for the apparent cosmic order.

(Old News, History of Astronomy. Astronomy Magazine, August 1976)

Clavius and Tycho Source of the photograph: sfutcher.co.uk

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We reproduce these fine photographs here as a source of inspiration for all who aspire to excellence in astrophtograhy.

Open Cluster M 11 or the Wild Duck Cluster photographed on amateur astrophotography equipment. Source of the photograph: Rawastrodata commons.wikimedia.org/wiki/File:The_Wild_Duck_Cluster_M11.jpg

Galaxy NGC 253 or Sculptor Galaxy. Source of the photograph: eso.org/public/images/eso1025a Emerson/Vista

The Orion Nebula. This image is in the public domain. Source: http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/01

The Horsehead Nebula. Horsehead Galaxy. To the famous question – Where in the present universe did the Big Bang occur? – the answer is clearly, everywhere (quotations from Megan Jorgensen). Source of the photograph: Ken Crawford imagingdeepsky.com/Nebulae/Horsehead/Horsehead.htm

The Omega Nebula. Source of the photograph: eso.org/public/images/eso0925a