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| Brightest Stars on Jul 29, 2014

Star Skat is near radiant for Delta Aquarid meteors

How to spot it, plus an explanation of why meteors in annual showers have radiant points.

The Delta Aquarid meteor shower – going on now – takes its name from the star Skat – also known by its Greek name Delta Aquarii. This star is not prominent. It ranks as the third-brightest star in the dim constellation Aquarius the Water Bearer. Still, you can glimpse this constellation and this star, if you go someplace nice and dark. If you’re in the N. Hemisphere, you’ll also need a good view to the south.

Skat or Delta Aquarii appears modestly bright in a dark country sky. It’s near on the sky’s dome to a very bright star, Fomalhaut in the constellation Piscis Austrinus the Southern Fish. Fomalhaut and the Great Square of Pegasus can help you find Skat. More about that below.

Radiant point of Delta Aquarid meteor shower

Radiant point for Delta Aquarid shower is near star Skat, or Delta Aquarii. You can locate this star by first finding the Great Square of Pegasus. Skat is found roughly on a line drawn southward through the stars on the west side of the Great Square. It’s between the Great Square and the bright star Fomalhaut, in the constellation Piscis Austrinus.

Want to see the star Skat?  This chart might help.  Chart via Wikimedia Commons.

Want to see the star Skat? This chart might help. Chart via Wikimedia Commons.

The Delta Aquarids peak in late July and early August, a wonderful fortnight prelude to the famous August Perseid meteor shower each year. If you watch on a clear dark night, you can see Delta Aquarid meteors streaking along in all parts of the sky. If you trace their paths backward, however, you’ll find that all Delta Aquarids appear to originate from a point near this star.

The point that nearly aligns with the star Skat (Delta Aquarii) is called the radiant point of the Delta Aquarid meteor shower. In actuality, the meteors have nothing whatever to do with this star. The meteors burn up some 100 kilometers (60 miles) above the Earth’s surface, while the star Skat lies about 160 light-years away.

Read about all the major meteor showers: EarthSky’s meteor shower guide

When you stand on a railroad track, you can see the illusion of tracks converging in the distance.  Likewise, the paths of meteors in a single meteor shower appear to converge at a point on the sky's dome.  This is the shower's radiant point.

When you stand on a railroad track, you can see the illusion of tracks converging in the distance. Likewise, the paths of meteors in a single meteor shower appear to converge at a point on the sky’s dome. This is the shower’s radiant point. Image via Shutterstock.

A meteor shower results when the Earth passes through the orbital path of a comet, and the debris from this passing comet vaporizes in the Earth’s upper atmosphere. The meteors enter Earth’s atmosphere on parallel paths. Seeing them come from a radiant point in the sky is much the same illusion as standing on railroad tracks and seeing the tracks converge in the distance.

The Delta Aquarid meteor shower is best in late July and early August. At that time, the star Skat and constellation Aquarius rise above the horizon in the hours between midnight and dawn. They are best seen in the evening sky in the months of October, November, and December. But they are best seen between midnight and dawn during the months of the shower. No matter when you look, you’ll always find Skat to the south (or below) the Great Square of Pegasus and to the north (or above) the bright star Fomalhaut.

Bottom line: The Delta Aquarid meteor shower is named for the star Skat, or Delta Aquarius, third-brightest star in the constellation Aquarius the Water Bearer.

Great Square of Pegasus: Easy to see

Fomalhaut: First visible extrasolar planet