Report for 2001-10-05

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Welcome to the Utah Skies Report.
Brought to you from beautiful Park City, "View-tah".

Astronomical Times

Sunrise: 7:27 am	Sunset: 7:04 pm
Astronomical Twilight Ends: 5:56 am	Astronomical Twilight Begins: 8:35 pm
Moonrise: 9:00 pm	Moonset: 10:24 am

Viewing Outlook

We've been on a roll weather-wise. I can't remember the last cloudy day we've had. Clear skies have been overhead for nearly a month now.  I know we need the rain, but... the clear skies have definitely been a welcome treat for me. Looks like the rain is coming.

Hubble Vision

The Hubble Space Telescope has distinguished itself as the premier source of astronomical images. Amazing HST images have graced the covers of major magazines and newspapers worldwide. In recognition of the amazing advances in astronomy and physics which have come from Hubble discoveries, we'd like to devote a section of this report to share some of them with you.

IC 418: The "Spirograph" Nebula According to the Hubble Heritage team, NASA's Hubble Space Telescope snapped this remarkable view of the planetary nebula IC418. Glowing like a multi-faceted jewel, IC418 lies about 2,000 light-years from Earth in the direction of the constellation Lepus. This photograph is one of the latest from NASA's Hubble Space Telescope, obtained with the Wide Field Planetary Camera 2.   A planetary nebula represents the final stage in the evolution of a star similar to our Sun. The star at the center of IC 418 was a red giant a few thousand years ago, but then ejected its outer layers into space to form the nebula, which has now expanded to a diameter of about 0.2 light-year. The stellar remnant at the center is the hot core of the red giant, from which ultraviolet radiation floods out into the surrounding gas, causing it to fluoresce. Over the next several thousand years, the nebula will gradually disperse into space, and then the star will cool and fade away for billions of years as a white dwarf. Our own Sun is expected to undergo a similar fate, but fortunately this will not occur until some 5 billion years from now.  The Hubble image of IC 418 is shown in a false-color representation, based on Wide Field Planetary Camera 2 exposures taken in February and September, 1999, through filters that isolate light from various chemical elements. Red shows emission from ionized nitrogen (the coolest gas in the nebula, located furthest from the hot nucleus), green shows emission from hydrogen, and blue traces the emission from ionized oxygen (the hottest gas, closest to the central star). The remarkable textures seen in the nebula are newly revealed by the Hubble telescope, and their origin is still uncertain.

Focus on Planetary Nebula

What do the Owl, the Cat's Eye, the Ghost of Jupiter, and Saturn have in common? They're all planetary nebulae of course(!), glowing gaseous shrouds shed by dying sun-like stars as they run out of nuclear fuel. Beautiful to look at, the symmetric, planet-like shapes of these cosmic clouds, typically 1,000 times the size of our solar system, evoke their popular names. Flipping through digital pictures made by participants in the Kitt Peak National Observatory Visitor Center's Advanced Observing Program, astronomer Adam Block created this delightful animation. Ten different planetary nebula images are presented, each registered on the central star. In order, their catalog designations are NGC 1535, NGC 3242 (Ghost of Jupiter), NGC 6543 (Cat's Eye), NGC 7009 (Saturn Nebula), NGC 2438, NGC 6772, Abell 39, NGC 7139, NGC 6781, and M97 (Owl Nebula). This glorious final phase in the life of a star lasts only about 10,000 years.  If the accompanying image file is not cycling through a bunch of nebula pics, hit the refresh button on your browser.

Space Weather Update

This image, captured on September 22 -- the date of the autumnal equinox, was made by the EIT camera onboard the SOHO spacecraft, a space observatory which can continuously observe the Sun. What a wild, energetic image of our star. It looks like a seething cauldron of energy -- far different from the featureless image most of us are accustomed to. The level of solar activity has risen dramatically in the last couple of weeks or so. Reports of auroral activity have been coming in from many locations to our north. Unfortunately, none have been spotted this far south. Yet! Northern Lights have been confined to magnetic latitudes greater than ~55 degrees (e.g., northern Europe, Alaska, Canada, and the northern tier of US states). Oh, well.

The accompanying image, by Lyndon Anderson, was captured near Steele, North Dakota. Only observers at high northern latitudes have been able to watch the recent spate of northern lights.

Lunar Phase

The moon was full on Tuesday -- meaning that we're approaching last quarter this coming Tuesday.  The accompanying image of craters Tycho and Copernicus by Steve Mandel and Hidden Valley Observatory is a fine example of the lunar details which can be viewed with an amateur telescope.

Planetary Report

Mars is rising in the southeast around  3:10 pm. It will be high in the south-southwest by the time it gets dark. We're rapidly losing Mars. The Earth has pulled away from Mars in it's orbit causing Mars to  shrink - it is currently  down to a measly 10" from 21" in June. Mars has finally reached the size where we're basically be unable to make out any surface detail. It has dimmed significantly as well - currently shining at magnitude -0.29 down from -2.4 in June.

Saturn joins us now about 10:05 pm. Look for Saturn in the east-northeast. Saturn has grown to an an impressive 19" and currently shines at magnitude -0.09.  The accompanying image by Dr. Richard Jacobs illustrates the changing seasons on Saturn. Seasons? Yup! Saturn has seasons just like Earth. Well, sort of. Examine the pictures. They were taken almost 1 year apart. Notice that the bottom image shows Saturn inclined much more so than the top. This is the same thing which causes the changing of the seasons here on Earth.

Next, look for Jupiter rising around 12:05 am. Jupiter is the king of the Planets. It is more massive than all the other planets combined. Jupiter is currently shining at mag -2.27 and it covers a whopping 39". That's more than twice the apparent size of Saturn and almost 5 times that of Mars! Jupiter is also rising earlier each week. It'll soon take is rightful place as the star of nighttime observing targets. I got some really nice views of Jupiter on Monday morning. As dawn came upon me an my telescope, Io was in the early phases of one of its regular transits. You definitely need to add Jupiter to your list of regular viewing targets again. And, speaking of transits, you have to check out the tools section of the Utah Skies website for a cool java applet which depicts the relative position of the four major moons. It's called JavaJup. I regularly refer to JavaJup to help plan my viewing sessions.   The accompanying image taken also by Dr. Richard Jacobs reveals an incredible amount of detail on the giant planets surface. Also, notice the tiny moon Io and its shadow on the left side of the image.

Venus is the last to arrive on the scene, rising at about 5:30 am. While still the brightest planet in the sky at mag -3.94, Venus is now rising close to sunrise and definitely losing some of its brilliance to  the soon to be rising sun. Notice that I emphasized the word some. I saw Venus the other morning and it still looked pretty impressive. If you're out before the sunrise, take a glance to the east. You'll see Venus blazing away. Anyway....We'll get another amazing performance from Venus late in the winter and into the spring as it takes charge of the nighttime sky.

Constellation Report

Our Constellation report is an easy way for people to become familiar with the nighttime sky. We’ll discuss myths associated with the various constellations as well as describing the numerous deep sky objects residing in the area. No equipment is required to view the constellations, though a star chart can be quite helpful. This ease of observing makes constellations a natural place to begin your journey to the stars.  This weekend we move on to the constellation Draco the Dragon.  The extended constellation of Draco is shown in the accompanying image (see lines). This very northern constellation goes half way around the celestial pole and the constellation of Ursa Minor, which is partly visible here above of Draco. Distinctive is the trapeze in the lower left part of the image which represents the head of the dragon. In the sky you can find it just north of the constellation Hercules.   In mid of July it culminates at about 21:30 local time, but because of its northern position it is circumpolar for most observers on the northern hemisphere and thus can be seen most time of the year.  Draco is the 8th largest constellation, occupying over 1,000 square degrees in the sky as it winds from the Pointers of Ursa Minor nearly to Vega in Lyra. Yet it has no bright stars.

Deep Sky Report
The focus of our efforts this week will be the deep sky objects of Draco. To find Draco, look 

Let's start things off with Barred Spiral Galaxy NGC4236(mag9.6). Located 1.5° WSW of Kappa Draconis, this galaxy is situated in such a manner (almost edge-on) that it's spiral arms are viewed against a background of the galaxy itself. As such, they are therefore quite difficult to see. Located some 10 million light years distant, NGC4236 spans 18.6' x 6.9'.

Next up is a beautiful Planetary Nebula NGC6543(mag8.3), also known as the Cat's Eye Nebula. Due to the beauty captured in this Hubble Space Telescope image, the Cat's Eye Nebula is one of the most popular planetary nebula out there. Located about 15° north of Gamma Draconis, this planetary nebula is visible as a blue/green oval in instruments as small as 6". In larger instruments (10-12") and under dark skies, the mag 11 central star becomes visible. Checkout the highly complex structure captured in this image. Astronomers are still trying to figure out what forces would have caused this. One theory suggests that this actually is an extremely tight binary system with the gravitational interaction of the two stars producing the exotic structure.

Next up is the Lenticular Galaxy NGC5866(mag9.9). A lenticular galaxy is essentially a spiral galaxy without the spiral part. These are often quite difficult to tell from elliptical galaxies. It is seen almost exactly edge-on. Notice the fine dark dust lane in this image. This galaxy the brightest of a group of galaxies lying roughly 40 million light-years distant. Estimates place NGC 5866's mass to be about 1 trillion solar masses, so it is a considerably massive galaxy. The 5.2' diameter of NGC 5866 corresponds to about 60,000 light-years. This galaxy is also (sometimes) listed as M102 -- the missing Messier object. You see, there is no object listed at the location Messier wrote down for M102. Some have suggested that this is a duplicate entry of M101. Other have suggested that the NGC5866 could be what Messier meant if he had miscalculated one of his coordinates. Hmmm....

Our final stop in Draco leads us to this weeks Utah Skies Challenge Object, Edge-On Spiral Galaxy NGC5907(mag10.4). Actually, if you found our previous galaxy NGC5866, your almost there. NGC5907 is located less than 1° to the north east. Due to its relatively compact size of 12.3* x 1.8*, this galaxy should be fairly easy to track down.  Good Luck!

If you are able to find all of these objects, you may be one of the few, the proud, the Deep Sky Obsessed. 
E-mail your findings to DeepSkyObservations@UtahSkies.org.

Light Pollution Update

Has there ever been more waste than this? Hardly. Raising a child under light polluted skies is like depriving them of ever hearing music!

Old news to astronomers: satellite data show that light pollution has become serious throughout the world — and especially in the United States. Colors indicate night-sky brightness directly overhead due to artificial light: only the black areas are totally free of large-scale light pollution. While the east is undoubtedly the worst offender, I can easily make out the Wasatch Front in this image. At a time when politicians are struggling to control soaring energy costs, a new study by Italian and American researchers underscores just how much electricity we waste as light beamed uselessly into space -- estimates for the US alone exceed $2,000,000,000 (2 Billion Dollars).  The study also reveals that about two-third's of the world's population — and 99 percent of those living in the U.S. — endure at least some degree of light pollution in their nighttime sky. Worse, more than two-thirds of Americans and half of all Europeans can no longer discern the Milky Way with the unaided eye even on clear, "dark" nights. Light pollution is easily cleaned up, however. Use only as much light as you need Use it only when you need it Use it only where you need it Help us to reclaim our skies, "One Star At A Time!"

Next Weeks Report
Next week, we'll continue our journey through the cosmos and focus on the constellation Cephus. 

 

Stay up to date on astronomical happenings by regularly checking the Utah Skies website at http://www.UtahSkies.org

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