Dance Across the Night Sky with Cassiopeia the Queen
Posted: October 24, 2010 Filed under: Alpha Cassiopeiae, American Astronomical Society, astronomers, Astronomical Societies, astronomy, astronomy equipment, Beta Cassiopeiae, binoculars, Charles Messier, constellations, entertainment, Gamma Cassiopeiae, John Hopkins University, M 103, M 52, Messier catalogue, NASA, National Solar Observatory, New General Catalogue, October 2010, Ptolemy, Royal Astronomical Society, spiral galaxies, telescope accessories, telescopes, the Milky Way galaxy, the Universe | Tags: Alpha Cassiopeiae, Beta Cassiopeiae, Cassiopeia the Queen, constellations in the northern sky, constellations viewable in autumn's northern sky, Gamma Cassiopeiae, Halloween star treats, Journey to the Beginning of Space and Time, M 103, M52, NGC 129, NGC 581, NGC 7654, Ptolemy, time machine to the stars 2 Comments »Cassiopeia the Queen is one of the first northern deep sky objects we’ll view during our “Journey to the Beginning of Space and Time”. Cassiopeia the Queen is easily recognizable in autumn’s night sky using her characteristic W or M shape form and she was one of the 48 constellations originally listed by the 2nd century Greek astronomer Ptolemy during his observations of the night sky. Today, Cassiopeia the Queen is one of 88 constellations recognized by modern star gazers in the night sky, and the abundance of magnificent open star clusters within her arms provides viewers with a chance to see a variety of outstanding celestial objects that have been entertaining star gazers for thousands of years.
Cassiopeia the Queen is a familiar sight for modern astronomers and star gazers in the mid-northern latitudes of planet Earth, and is often one of the first constellations in the northern sky beginning star gazers journey to view. Board your time-machine-to-the-stars near the end of October, or the beginning of November, and take the family on a journey through time and space to visit Cassiopeia the Queen. A visit with Cassiopeia the Queen will open a child’s mind to the possibilities of the universe, before them, and your wife will be able to tell her friends that you took her out last night.

8x50 astronomical binoculars will reveal about 12 stars nestled in among the collective glow of other stars to faint to resolve
One of the best open star clusters you can view with the naked eye is 6.5 magnitude NGC 129, a large, bright, open cluster of stars 8×50 astronomical binoculars will reveal to have six to twelve brighter stars nestled within the collective glow of a field of stars to faint to resolve using binoculars. You should see about 35 celestial bodies in this region of space and time 5,200 light years distant from your position on the Earth. Look toward the north of two 9th magnitude stars, near the center of NGC 129, and you’ll find the Cepheid variable DL Cassiopeiae. DL Cassiopeiae will fluctuate between 8.6 and 9.3 magnitude, over the course of an eight-day cycle.
The central star in Cassiopeia’s characteristic W is Gamma Cassiopeiae, a prototype for a class of irregular variable stars believed to be rapidly spinning type-B celestial bodies often fluctuating by as much as magnitude 1.5 or more, Gamma Cassiopeiae will flicker between 2.2 and 3.4 magnitude as you watch her nightly dance and this star at maximum brightness outshines both Alpha Cassiopeiae and Beta Cassiopeiae. Astronomers believe these apparent fluctuations are due to a decretion disc around this star resulting from the rapid spinning of the star, which results in some of the star’s mass forming a decretion disc. Gamma Cassiopeiae is also a spectroscopic binary star with an orbital period of about 204 days and astronomers believe Gamma Cassiopeiae’s companion star is about the same relative mass as Sol. Part of a small group of stellar sources in the night sky that beam of X-ray radiation about 10 times higher than the X-rays emitted from other type-B stars across the cosmos, Gamma Cassiopeiae exhibits both short-term and long-term cycles of x-ray emission. Star gazers should also be able to view Gamma Cassiopeiae as an optical double star, with a faint magnitude 11 companion star, about 2 arc seconds distant from Gamma Cassiopeiae.
Ancient star gazers in China called Gamma Cassiopeiae Tsih, which loosely translates as “the whip”, but no references have been found in Arabic or Latin texts of Gamma Cassiopeiae being referred too using a different name. Modern star gazers refer to Gamma Cassiopeiae by a number of different designations, including 27 Cassiopeiae, HR 264, HD 5394, and others. Modern astronauts often use Gamma Cassiopeiae as a star-guide because it’s a relatively bright celestial object and in previous space missions this star was used as an easily recognizable navigational reference point in the night sky.
M103 (NGC 581) is the first of two Messier objects in Cassiopeia’s arms viewable through a six-inch time-machine-to-the-stars and should appear as about three dozen stars grouped in a triangular area 6′ across. A fairly compact open cluster, M103 will be 1 degree east of Delta Cassiopeiae, and is the left bottom star of Cassiopeia’s characteristic W shape marking her throne in the night sky. Pierre Mechain was first given credit for seeing this open cluster in the night sky in 1781. Star gazers using 8×50 binoculars will see about 25 magnitude 10 or fainter stars in their view and a string of four stars immediately to M103′s southeast, which adds to the beauty of viewing M103, significantly.
The second Messier object in Cassiopeia catalogued by Messier is M52 (NGC 7654), you can locate M52 by drawing a line from Alpha Cassiopeiae through Beta Cassiopeiae, and then extending your line an equal distance to M52. An 8-inch time-machine-to-the-stars will reveal about 75 stars in the night sky clumped in various patterns along the edge of the Milky Way that aren’t lost among the background points of light behind these stars. One of the richest open clusters in Cassiopeia’s arms and north of the celestial equator, Messier made note of M52 in his catalogue in 1774. This open cluster will appear as a nebulous mass of about 100 stars in 8×50 astronomical binoculars, with a few individual stars that you can resolve a little better. Star gazers looking for a little extra should look to the north of M52 to find Harrington 12, a wide triangular looking asterism containing about a dozen 5th to 9th magnitude stars, which will appear spectacular in low-power astronomical binoculars.
Journey less than 3 degrees south of Delta Cassiopeiae to find the spectacular Owl Cluster (NGC 457), a celestial object ancient star gazers could plainly see in the north night sky, the Owl Cluster’s wings will be clearly viewable using a 4-inch time-machine-to-the-stars. Star gazers can also locate Delta Cassiopeiae by using 5th magnitude Phi Cassiopeiae and 7th magnitude HD 7902, which lie to the southeast of the Owl Cluster. The Own’s eastern wing is a line of four bright stars, while the western wing is composed of two pairs of stars arranged in a long rectangle. The brightest star in the Owl Cluster will shine at 8.6 magnitude and will appear a little orange in color in star gazers.
Millions of Light-Years and Infinity Inbetween
Posted: October 18, 2010 Filed under: astronomers, astronomy, Charles Messier, Gerald de Vaucouleurs, John Herschel, Messier catalogue, star catalogues, star evolution, Ursa Major North Group, Ursa Major South Group, Virgo supercluster, William Herschel | Tags: astronomers, astronomy, Charles Messier, Coma Berenices, Gerard de Vaucouleurs, John Herschel, Journey to the Beginning of Space and Time, Local Group of galaxies to Milky Way, Messier catalogue, Messier objects, Milky Way, time machine to the stars, Ursa Major North Group, Ursa Major South Group, Virgo, Virgo supercluster, William Herschel Leave a comment »
Look upward at the night sky and you’re viewing the stars of the Milky Way galaxy as they were hundreds and even thousands of light-years in the past. The time it takes the starlight from these celestial bodies to travel the distance between these stars and Earth is very long in human terms, despite the speed of light. If astronomers indicate that a particular galaxy is sixty-million light-years away from Earth, this means it takes light sixty-million light-years to travel the distance to Earth from this galaxy. The true environments existing in distant galaxies remains a mystery for the moment. We’ll board our time-machine-to-the-stars tonight and “Journey to the Beginning of Space and Time’ to take a look a look at the local group of galaxies within the gigantic wheel of the Virgo Supercluster. The physical reality existing in these distant galaxies is likely to be unlike anything imaginable by humankind and things out among distant galaxies doesn’t work as you have been taught things work on Earth. Travelers unfamiliar with Einstein’s relativity need to bone-up on special and general relativity, before getting on board, this will help you deal with the realities of your “Journey to the Beginning of Space and Time”.
Astronomers looking upward into the night sky realised centuries ago that deep-sky objects are distributed unevenly about the night sky. French comet hunter Charles Messier (1730-1817) looking upward into the night sky through his time-machine-to-the-stars compiled a popular catalog of deep-sky objects. His catalogue contains high concentrations of deep-sky objects within the Milky Way above you, where open star clusters and star-forming areas that form them congregate.
Messier’s catalogue also contains entries on 16 objects he located near the border between the constellations Virgo and Coma Berenices. Star gazer William Herschel (1738-1822) and his son, John Herschel (1792-1871), recorded more than 200 celestial objects in this same region of the night sky. It would be in the 1920s and 1930s that astronomers would determine that these nebulous objects are in fact galaxies as big, or larger than, the Milky Way galaxy that constitute a cluster of galaxies far beyond the Milky Way.
Two decades later, French-born astronomer Gerard de Vaucouleurs (1918-1995) noted that the halo of galaxies surrounding what astronomers referred too as the Virgo cluster actually extends all the way to our Local Group of galaxies, which the Milky Way calls home. Today astronomers refer to this Local Group of galaxies as our Local Supercluster of galaxies.
Presently, astronomers believe our Local Supercluster extends 50 million light-years, from the center of the Virgo cluster. We’ll journey from the center of our Local Group to slightly beyond the Virgo cluster. Along the way we’ll stop at all of the galaxy groups and clusters containing at least three reasonably large galaxies and see what astronomers have determined about these distant celestial bodies in the night sky above you.
The first celestial object in the night sky we’ll journey to see is called the Ursa Major North Group, next we’ll travel to Ursa Major South Group, and then make our way to each of the galaxy groups and clusters in the Milky Way’s Local Group of neighbors.






