Bookstore Books Books2 Software Front Desk 
|
|---|
Solar Flare Could Wipe Out All Life on Earth - SuperFlares have been observed on other stars that are like our own sun. - BBC, September 22, 1999.
Universe is expanding faster - New evidence indicates that the universe may be expanding even faster than first thought. . - CNN, September 22, 1999.
Uranus has 21 Full Moons - Hawaii's telescope spots a new moon. - ABC, September 21, 1999.
Weather Satellite Nears Mars - Mars Climate Orbiter is set to go into orbit around the Red Planet. - SSN, September 21, 1999.
Europa May Have Tidal Forces - Cracks on Europa may be caused by tides from Europa's ocean. - MSNBC, September 16, 1999.
Earth Sized Planet Found - About 20 planets outside our solar system have been found. This is the first time a earth size planet has been discovered. - BBC, September 14, 1999.
First Pictures Taken by Mars Climate Orbiter - The weather satellite is scheduled to reach Mars on September 23. - CNN, September 13, 1999.
Supernova Remnant Imaged by Chandra - Scientists take Chandra telescope out for at test drive. - September 10, 1999.
September Skies
Current Phase
of the Moon
September 02 - Last Quarter
September 09 - New Moon
September 17 - First Quarter
September 25 - Full Moon
No Major Meteor Showers
Skywatching Center - Current Month's Skies.
Astronomy Magazine - The Sky Show in September 1999.
Sky & Telescope - September 1999 Skies.
by Steve Coe
Aquarius
Aquarius is the kind of constellation that I like, it has variety. I get very bored with too much of any object type. By the time I am doing my 8th planetary in Cygnus or the 10th globular in Ophiuchus or (dare I say) my 50th galaxy in Virgo, I am ready for a break. Aquarius has a fun potporri of deep sky objects in many sizes, shapes and details. So, let's look at some goodies in Aquarius, the Celestial Culligan Man.
NGC 6981 is M 72, using my 17.5" f/4.5 from years ago, I saw it as bright, pretty large, round, much compressed and much brighter in the middle. This compact globular is easily resolved at 150X. It has an inner bright region with a well-resolved outer section which showed 20 stars resolved on a night I rated 7/10 for seeing. I could see a faint glow in a 10X50 finder. Years later with my 13" on a mediocre night that I rated 5/10, I was only able to resolve 12 stars at 220X.
NGC 7009 is the Saturn Nebula, a famous planetary with outer ansae (wing-like projections) and a bright inner disk. It was discovered by William Herschel in 1782 but Lord Rosse was the first to see the extending ansae. The projections reminded him of the planet Saturn and he gave this object its' nickname. Amateurs have been trying to duplicate that observation ever since.
Using the 13" about 60 miles from the lights of Phoenix on a 8/10 night, it was bright, pretty large and elongated 1.5 X 1 in PA 75 degrees. Using 220X the central star and ansae are obvious and the nebula is light green.
This observation of the Saturn Nebula is made with Helen and Richard Lines' 20" f/6 Newtonian in Meyer, Az. The nebula is bright, small, somewhat elongated and light green at 150X. Raising the power to 225X will show the ansae as faint projections from the bright central section. At 400X the central star is obvious and the ansae stand out more clearly. One of the bright spots along the ansae (Helen Lines calls them wing tanks) is visible at this higher power. All these observations are on a night I rated 7/10 for seeing and transparency and I found that the UHC filter did NOT help with either the central disk or the ansae detail. Several observers, myself included, saw the nebula as light green, without the UHC filter installed.
I had the good fortune to use Jeannie and Tom Clark's 36" f/5 at the Ultimate Star Party and it provided my best view of the Saturn Nebula ever. With a 16mm eyepiece and all that aperture it is a lovely blue-green oval with a blazing central star. The ansae or wings of the Saturn nebula are immediately obvious, as is the left hand "wing tank", a bright knot in the extension of the nebula. The right hand "wing tank" is seen better with averted vision, both are seen as thickenings within the ansae. The central section is elongated 2.5 X 1 and there is a thin dark region which surrounds the central star. WOW!!
NGC 7089 (M 2) this is the showpiece of the constellation. It is bright, very large and very bright in the middle at 100X. This globular is easy in the 10X50 finderscope. At 250X in the 17.5" f/4.5 there are 12 stars resolved in the central core region and a profusion of stars in the outer corona. All these stars are superimposed on an unresolved background haze of stars. Lovely chains of stars meander outward from the bright core and several dark lanes are visible through the cluster. In the 13" on a 8/10 nite I counted 41 stars at 220X. There are two dark areas on the SE side. The entire globular has a lot of background sparkling stars.
NGC 7184 Faint, pretty small, much elongated 4x1 with a bright nucleus. There is a hint of a dark lane with averted vision at 135X. There are two attendant galaxies 20' to the NE, they are both very faint, small and round.
NGC 7492 is extremely faint, pretty small, round, not much brighter in the middle at 100X. This is a very low surface brightness globular with no stellar resolution at any power. If you are ready to take an observing break, this an easy object to locate. Put Delta AQR in the field of a low power eyepiece, turn off the drive and take a 13.7 minute break. When you return to the scope NGC 7492 will be in the field, honest. This star cluster was not easy to see in the 17.5" Dobsonian on a night I rated 8/10 for transparency.
Binocular fields
I have always loved to sit back in a lounge chair and just enjoy the sights of Our Galaxy with a pair of binoculars, it is very relaxing and just plain fun. There are several places in Aquarius that are worth some time scanning with binoculars. I recommend the areas near Psi and Omega AQR. These areas contain some beautiful curved chains of stars that cross each other and form interesting patterns in my pair of 10X50's. I would highly recommend looking at the sky with both eyes for a while.
Andromeda Galaxy
Andromeda Galaxy is located in the Andromeda Constellation. It is an easy object to find. The Andromeda Constellation looks like an upside down V. Each leg of the V has four stars. The top star being shared by both legs. From the top of the V move down to the third star on each leg. Mark the third star on the right leg and move left to the third star on the left leg. Keep moving left, the same distance that you moved from the right to the left leg. Andromeda Galaxy will be right there.
This is an easy object to find because you can see it with your naked eye. The Andromeda Galaxy is the farthest object you can see with your naked eye. It lies 2,200,000 light years from earth. On a clear night it will appear as a faint white fuzzy oval light.
Using a 10 inch telescope I can easily make out dust lanes. The dust lanes separate the spiral arms of the galaxy. Andromeda is a spiral galaxy. It appears elliptical because from earth you are viewing the galaxy almost on it's edge. This is why the dust lanes are not as detailed as they would be if you had an overhead view of the galaxy.
Andromeda galaxy is larger than the Milky Way. It has over 300 billion stars. The diameter of the galaxy spans over 150,000 light years. For comparison the Milky Way has about 200 billion stars and is about 100,000 light years in diameter.
Andromeda Galaxy has two companion galaxy. The closest companion is M110 or NGC 205. M110 is a round galaxy. It lies less than 1/2 degree south from Andromeda Galaxy. M110 was the last object to be added to the Messier list, in 1967. M110 is about 4,000 light years across. The second companion galaxy is M32 or NGC 221. M32 is a oval galaxy. It lies about 1 degree northwest from Andromeda Galaxy. M32 measures about 2,000 light years across.
The best thing about Andromeda is spending some time just viewing the galaxy on a clear night. I am always amazed to think about what I am actually looking at. Objects like this is what got me hooked on astronomy.
Photograph by Jason Ware, publisher of Galaxy Photography . Stop by his web site for other great astrophotographs. His work is copyrighted, so please do not copy them without his permission.
"I don't know what you could say about a day in which you have seen four beautiful sunsets." - John Glenn
The zodiac constellations originated with ancient Mesopotamian Astronomers and dates back as early as 3000 BC. The word zodiac is derived from the Greek word zodiakos kyklos, meaning "circle of animals". The zodiac is made up of 11 animals and one harp. Lyra, the harp, does not fit the definition of "circle of animals". It may not have been part of the original constellations. Full Story
Last month we discussed Lens Power. This month I would like to talk about lens sizes, field of view, and eye relief. Lenses come in three different sizes: .965",1.25", and 2". The .965" is used in some of the refractor telescopes. 1.25" is considered the telescope standard. And, the 2" is used by many upper grade telescopes. If you have a 2" mount you can usually use a 1.25" with an adapter.
Having a larger eye piece opens up the field of view. The field of view is expressed in degrees. If you stood on one spot and turned in one complete circle, that would be 360 degrees. If you held the lens to your eye, not attached to a telescope, you would see so many degrees through the lens. Lenses field of view range from 45 to 82 degrees. Tele Vue describes their lenses with a 82 degree field of view as a "spacewalk". That makes for a pretty good description. You can compare the difference by taking two lenses with different fields of view and holding them up to your eyes. You will be able to see more through the lens with a larger field of view.
Eye relief is also important, especially if you wear glasses. Eye relief is the distance between your eye and the lens while maintaining the entire field of view. Eye relief of 17mm is good, and 20mm is better.
I recommend Tele Vue, Pentax, Lanthanum, and Mead. Buy the best lens you can afford. If you take care of your lenses they should last a life time.
The Whole Mars Catalog A web site all about Mars. Current Mars news, searching for life on Mars, and the latest on missions to Mars. This site is a good place to start if you are interested in Mars.
Nova - To The Moon View 360-degree pictures of the moon. This is a fun web site where you can control the picture by zooming in and out. Must download plug-in. It is worth a visit.
StarLore This astronomy web site offers Star, Galaxy, Nebulae, Star, Cluster, and Monthly Deep Sky Indexes.
"Astronomy Digest" is presented to you as a free Astronomy Zine. If you enjoy this site please visit our sponsors listed in the blue boxes at the top and bottom of the page. Every time you click on one of the sponsor's links listed in the blue boxes, "Astronomy Throughout the Net" receives a small fee. It only takes a click.
Prior Issues
Newsletter
Aug ------ 2,152
July ------ 1,983
June ----- 1,942
E-Zine
Aug ------ 2,110
July ------ 2,055
June ----- 2,033
Please Email us if you would like to advertise your web site on "Astronomy Digest". We have many plans available.
