Report for 2002-04-26
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Brought to you from beautiful Park City, "View-tah".

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Contents
	This Weeks Issue	The Utah Skies Website
	Astronomical Times Viewing Outlook Space Weather Update Mission Update Comet Watch Lunar Phase Planetary Report Hubble Vision Constellation Report Deep Sky Report IDA-Utah Light Pollution Update	Astro-photographer of the Month Deep Sky Observers Hubble Vision IDA-Utah Light Pollution Update Weekly Report

Star Party
Mark your calendar. Utah Skies will be holding a star party Saturday night, May 4th from 9:00pm until 1:00am. We'll start the night off with views of a rare planetary conjunction. All 5 "classical" planets will be visible in the western sky shortly after sunset (show up early if you want to see them all). Working from west to east, we'll see Mercury, Venus, Mars, Saturn and Jupiter. Of course we'll visit a host of deep sky wonders such as the Whirlpool Galaxy, The Hercules Star Cluster and The Ring Nebula... to name just a few :) Checkout our viewing guide for additional details and an on-line map for directions. Hope to see you there!
Astronomical Times
Sunrise: 6:33 am	Sunset: 8:17 pm
Astronomical Twilight Begins: 4:50 am	Astronomical Twilight Ends: 10:00 pm
Moonrise: 8:05 pm	Moonset: 6:33 am

Viewing Outlook

After a serious dose of Park City "spring weather", things appear to be getting back to ... normal :) Skies have cleared a bit finally and we even got to do some viewing. The weekend forecast sounds less than optimal, but... hey.. we'll take what we can get, right? Plus... we still could use the water. There is a beautiful planetary alignment in the western sky taking shape after sundown. All the "classical" planets (those which have been known since antiquity) will be lined up from west to east. Mercury has finally joined the lineup...low and to the west. Venus continues to blaze in the west as it creeps higher and higher in the sky. Mars a fraction of it's former self shines next to the Pleiades star cluster. Saturn has faded significantly, but still outshines most of the stars in the sky. Saturn seems to be fading fastest at this point. Look for it to make the largest moves west. This is especially pronounced given that Mercury, Venus, Mars and Jupiter are all moving east. And then finally we have Jupiter... the king of the planets. It shines brightly just west of overhead after sunset. Jupiter is only outshined by Venus in the evening sky.  Viewing the alignment does not require any special equipment. Since the planets span such a wide section of the sky, no telescope or binoculars can see all of them simultaneously. All you need is a relatively flat horizon to the west to view the spectacle. If you've got obstructions to the west, you'll have trouble spying Mercury as it never really gets high enough to be seen in a dark sky. This event will continue for a couple more weeks. In fact, the tightest grouping of the planets will occur on May 14th when all five planets will be within a 33° span. So... don't feel rushed to get out there and see it. On the other hand... the next time this will happen is in 2040... So... don't wait too long either.

The Lyrid Meteor shower peaked last Sunday night. While never a huge event (meteor counts are typically in the 10-15 per hour range), this years event had a few notable meteors. The Lyrids are so named because they appear to radiate from the constellation Lyra.

Space Weather Update

There were a couple of large Coronal Mass Ejections (CME) last week. These precipitated several rounds of northern lights. The most active hit last Wednesday and was seen as far south as Arizona! Of course the skies over Park City have been stormy :( As you can see from the image at left, the sun is covered with sunspots at this point. Astronomers have said that none of these have the high energy, twisted magnetic fields which typically drive CME's. So... the next couple of days will probably be lacking any major solar activity. Checkout this awesome shot of an X-Class solar flare captured on April 21st.  This delivered a glancing blow on April 23rd and triggered another round of northern lights for high latitude observers.

Checkout this awesome shot by Dennis Mammana. He's not only captured an amazing aurora, but... he's even managed to catch comet Ikeya-Zhang (lower left) as it cruises through the sky. Wow!  This is such an impressive shot that NASA chose to display it as the Astronomy Picture of the Day on 4/22/2002.

Mission Update

The International Space Station will make a pass over the northern Utah this weekend. Your best shot for viewing this, the brightest object in the sky will be on Saturday night at 8:43pm when the station takes about one minutes to cross the sky. You can easily spot the ISS without any optical aid. Checkout NASA's Human Spaceflight website for times when the ISS will be visible in your area. Then, grab your binoculars or telescope and see what kind of detail you can pick out. Or... just go and eyeball humans in space. .  The International Space Station got a bit larger the other day. Astronauts recently added this huge truss section which will allow for future growth. Future growth includes a pair of Japanese and European built laboratories. Want more info? Checkout this NASA site. Visit CNN/Space to find out more.

Images are steadily coming back from the Mars Odyssey Spacecraft.. Image which might indicate a wet past... and maybe future for Mars. Water on Mars? Yup. That's the conclusion many are coming to as available information increases.   Checkout this recently released image from the Mars Odyssey Spacecraft. It appears that a section of the Martian surface was scratched by a giant claw. "White Rock" is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it.

Comet Watch: Comet Ikeya-Zhang

Comet Ikeya-Zhang continues to fade. It is now down to mag5.0, just barely visible to the unaided eye under dark skies. The comet has traveled so far north that It is currently visible in both the morning sky and the evening sky. In fact, if you have a clear view to the north you may be able to watch it all night. How can the comet be visible all night??? Good question. The reason is that the comet is now far enough north that is now circumpolar, and never sets. The comet reached that point a week or so ago for observers living at or above mid-northern latitudes... ie.. NY, Chicago, Denver, SLC, San Fran. This should make it easy for more people to view it. And, since it's still pretty bright, April will be a good month for viewing the comet.  I took this image using a 120mm f/5 refractor. It is the result of a two minute exposure using 800 speed film.

The accompanying image shows the path Comet Ikeya-Zhang will take on it's trip around the Sun. Notice how the tail of the comet changes direction as it rounds the Sun. This is caused by the solar wind. In fact, it was this very behavior which first caused astronomers to speculate about the presence of a solar wind. If there were no wind, one would expect the tail of a comet to always trail behind, but... as this image shows, the tail of the comet always points away from the Sun. Cool, huh? You can also see that the comet has recently passed between the Earth and the Sun and is now visible in the morning sky. I'm really looking forward to some clear skies so that I can take a peek and snap some pics.  Hopefully I'll be able to capture some good pictures and add them to the report soon.

Lunar Phase

The moon will reach first quarter tomorrow night (4/20). Rising around midday and setting around midnight, the moon will be high overhead by dark.  Checkout this awesome shot of the full moon by Utah Skies own Don Brown. Don used an Olympus D-340R Digital Camera through his Orion XT8 Newtonian Reflector (8" f/8) using eyepiece projection (25mm/49x)

Planetary Report

In this section, we visit the planets in the order in which they are currently rising. We do our best to track down the finest images available.  for 2002.  As an added feature, you may also click on any of the planetary images to view a planetary reference page filled with important facts about the planet.

Neptune 8th planet Rising 3:35am Visual Magnitude 7.93 Visual Diameter 2" Distance 30.16 AU Constellation Capricornus Checkout the accompanying Voyager 2 image of Neptune. Notice the detail in the planets cloud deck. Neptune has spots... just like Jupiter. These spots are huge storms. Neptune is a relatively easy target when viewed at the right time. That time, however is not now. Neptune is rising just before astronomical twilight begins. In other words, Neptune never really gets high enough in the sky for optimal viewing before the sky starts to brighten. It'll be best viewed in late summer and the fall, when it will high in the sky for hours before dawn. Almost star-like in binoculars, it shows it's beautiful blue color in telescopes. Neptune gets this beautiful blue coloring from a layer of Methane in its upper atmosphere. Located over 2.84 billion miles from Earth, Neptune has a huge circular orbit -- taking just over 164 years to orbit the Sun. In fact, Neptune's orbit varies by less than 1% from circular. Neptune has a couple of other claims to fame... It has the fastest wind speeds in the solar system with gust at almost 1500 mph. Similar to Jupiter, it is categorized as a gas giant. Neptune is roughly 17 times more massive than the Earth. In another similarity to Jupiter, Neptune has a  Great Dark Spot. William Herschel is credited with the discovery of Neptune in 1781. However, it had been recorded in several catalogs as a star as far back as 1690.

Uranus 7th planet Rising 4:00 am Visual Magnitude 5.87 Visual Diameter 3" Distance 20.36 AU Constellation Aquarius Checkout this shot of Uranus. You can clearly see several of it's moons in this image. At almost 2 billion miles away, this is one tough shot to make from Earth! Uranus is a relatively easy target. However, this is another tiny planet at only 3".  It is also rising at almost the same time as the sun. So... you'll have to wait a few months to seek it out. Additionally, given it's tiny size, It displays absolutely no surface detail. It does however show it's beautiful aquamarine color. Uranus also gets its beautiful coloring from a layer of Methane in its upper atmosphere. Located over 1.92 billion miles from Earth, Uranus has a huge orbit -- taking just over 84 years to orbit the Sun. It is categorized as a gas giant as is Jupiter, Saturn and Neptune. Uranus is roughly 14 times more massive than the Earth. Discovered by William Herschel in March of 1781, Uranus was the first planet to be "discovered". All the others are plainly visible, and hence have been known since antiquity. The name Uranus was suggested for mythological reasons. Since Jupiter was the father of Saturn, it made sense to name the next planet out Uranus -- the father of Saturn.

Mercury 1st planet Rising 7:20 am Visual Magnitude -0.47 Visual Diameter 7" Distance 1.03 AU Constellation Aries The accompanying Mariner 10 image of Mercury's southwest quadrant reveals the amount of destruction brought upon the planet by comets and meteors. Since Mercury has no atmosphere, every object coming its way is able to score a direct hit. This image was taken a the spacecraft made it's closest pass to the planet at a distance of about 120,000 miles. The largest craters are about 60 miles in diameter. Mercury has gotten really bright over the last several weeks. It is now rising about 45 minutes after the Sun. So... you've got about 45 minutes after sunset to spy tiny Mercury above the western horizon. Mercury will climb even higher in the next week or two making this the best time all year to spy the tiny planet.

Venus 2nd planet Rising 7:50 am Visual Magnitude -3.93 Visual Diameter 11" Distance 1.49 AU Constellation Taurus Checkout this cool shot of Venus from the Galileo Spacecraft taken as it swung past the planet a couple of years ago. Since Venus has such dense clouds, we can not see through to the surface. Nevertheless, we can learn quite a bit anyway. Astronomers have studied the winds and atmospheric composition of the planet. Venus is now rising about 75 minutes after the sun... it has slowly but surely moved to take up its role as the Evening Star. Many of you have no doubt seen it blazing away in the western sky after sunset. Watch as it climbs higher and higher over the next few months. By late spring and through the summer and Fall, Venus will dominate the night sky.  Did you know that Venus goes through phases? No... not those kind of phases... Phases of illumination, like the moon. It's true. Venus is current a round 96% illuminated sphere. As it climbs higher in the sky (larger angular separation from the Sun) the illuminated portion shrinks. By the time Venus is only 1/2 illuminated, it will have brightened to mag -4.3. It will continue to brighten to about mag -4.7 late in the fall when it reaches its greatest elongation (angular separation from the Sun). At that point, Venus will be only about 1/4 illuminated, but will have grown to over 44".

Mars 4th planet Rising 8:15 am Visual Magnitude -3.93 Visual Diameter 11" Distance 1.49 AU Constellation Taurus Checkout this sweet image captured by the orbiting Mars Global Surveyor.  Notice how much ice had accumulated at the south polar region. The Earth continues to pull away from Mars in it's orbit. In fact, the distance between the two planets has grown from about 40 million miles this summer to over 175 million miles. This has caused Mars' apparent diameter to shrink. It is currently down to a measly 4".. a tiny fraction of it's peak of 21" in June. In fact, this is just about as small as Mars ever gets. It has also dimmed significantly as well - currently shining at a wimpy magnitude 1.57 down from -2.4 in June.  Mars will return for an even better pass in 2003. In the mean time, we can live vicariously through the works of the Maple Ridge Observatory. If you haven't checked out their website, I'd highly recommend it. It's loaded with many awesome planetary and deep sky image that'll blow your mind.

Saturn 6th planet Rising 8:40 am Visual Magnitude 0.12 Visual Diameter 17" Distance 9.84 AU Constellation Taurus Checkout this absolutely amazing mage of Saturn as captured by Ed Grafton. What an awesome shot. Notice the innermost ring. It's called the Crepe ring and it's almost transparent. Just so you know... this image was not taken from an observatory. Nope. This was taken from his backyard in Houston, Tx. Look for Saturn well west of overhead as it gets dark. If you haven't been looking at Saturn recently, you'd better start. It's gonna be gone soon :(   At this point, Saturn sets about 1.5 hours after the Sun. Saturn has currently spanning about 17" -- this is well shy of it's peak size and is currently shining at magnitude 0.13 -- which is also down considerably from its brightest. Don't waste any time... NOW is a great time to view Saturn. It will stick around through the remainder of the winter and into the spring, but.. your views will be best RIGHT NOW.

Jupiter 5th planet Rising 8:40 am Visual Magnitude 0.12 Visual Diameter 17" Distance 9.84 AU Constellation Taurus Here's another beautiful image by Ed Grafton.  This is a very cool shot! In fact, his whole website is loaded with awesome images like this. Notice the inky dark spot in the upper left. That is actually the shadow created by Jupiter's moon Ganymede. Jupiter is the king of the Planets. It is more massive than all the other planets combined. In fact, Jupiter is over 300 times more massive than the Earth. Not surprisingly, Jupiter also has the largest moon in the solar system, Ganymede. Jupiter is currently shining at mag -2.07 and spans 36". This is off quite a bit from it's peak of 47" earlier this winter...  It too has passed the meridian by the time it gets dark. You'd better take advantage of what's left of the good Jupiter views. They won't get any better till next fall.  If you're planning on viewing Jupiter's Great Red Spot, you'll want to checkout this Sky and Telescope article which contains a list of Great Red Spot Transit Times.  Many of the features visible in this image are within the reach of modest amateur telescopes. And why not? These images were taken from suburban Houston using a 14" Celestron. Depending on the size of the telescope and the quality of your skies, you might even do better! In fact, on a few amazingly steady nights I have. I'll remind you again. 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 Jovian moons and their shadows. It's called JavaJup. I regularly refer to JavaJup to help plan my viewing sessions.

Pluto 9th planet Rising 11:05 pm Visual Magnitude 13.83 Visual Diameter <1" Distance 29.74 AU Constellation Ophiuchus Checkout this awesome series captured by Gordon Waite. This series depicts how Pluto was originally discovered. After years of searching for a planet beyond Neptune, Clyde Tombaugh in 1930 came upon Pluto. His was not a simple discovery. He didn't just scan the sky with his telescope and see Pluto. Nope. He took countless images of the sky. Each image would be compared to an image taken days or weeks earlier. While the stars are essentially motionless over short periods of time, solar system objects would appear to move. On February 18, 1930, Tombaugh compared images taken on January 23rd with images taken on January 29th. While blinking the images, a technique which alternates the images from one side to the other, he noticed that one of the stars moved. That star was actually the planet Pluto. And so on that fateful day, the population of our solar system increased by one. No other planets have been found in our solar system since! Pluto has brightened another whopping .01! But don't get too excited, it's still a tiny, faint little spec in a telescope... any telescope.  It is currently over 2.8 billion miles from Earth. Located in the southeastern sky before sunrise, Pluto is also not very well placed at this point for viewing. You'll have a much better chance of viewing Pluto late in the spring or in the summer. (Just in case you're having trouble, you should see Pluto dancing towards the lower left corner of the image. If you don't, hit your browsers "Reload" button.)

Hubble Vision

The Hubble Space Telescope has distinguished itself as a 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 some of these incredible images, and share some of them with you. Our latest comes directly from the Hubble Heritage Team.

Hubble Snaps Picture of Remarkable Double Cluster The double cluster NGC 1850, found in one of our neighboring galaxies, the Large Magellanic Cloud, is an eye-catching object. It is a young, "globular-like" star cluster -- a type of object unknown in our own Milky Way Galaxy. Moreover, NGC 1850 is surrounded by a filigree pattern of diffuse gas, which scientists believe was created by the explosion of massive stars.   NGC 1850, imaged here with the NASA Hubble Space Telescope, is an unusual double cluster that lies in the bar of the Large Magellanic Cloud, a satellite galaxy of our own Milky Way. After the 30 Doradus complex, NGC 1850 is the brightest star cluster in the Large Magellanic Cloud. It is representative of a special class of objects -- young, globular-like star clusters -- that have no counterpart in our galaxy. The two components of the cluster are both relatively young and consist of a main, globular-like cluster in the center and an even younger, smaller cluster, seen below and to the right, composed of extremely hot, blue stars and, fainter red T-Tauri stars. The main cluster is about 50 million years old; the smaller cluster is only 4 million years old.   One of Hubble's main contributions to the study of NGC 1850 is in the investigation of star formation at both ends of the stellar mass scale -- the low-mass T-Tauri stars and the high-mass OB stars.   T-Tauri stars are young, solar-class stars that are still forming, so young that they may have not started converting hydrogen to helium, which is how our Sun produces its energy. Instead they radiate energy released by their own gravitational contraction. By investigating these stars astronomers learn about the births and lives of low-mass stars. T-Tauri stars tend to occur in crowded environments, but are themselves faint, making them difficult to distinguish with ground-based telescopes. However, Hubble's fine angular resolution can pick out these stars, even in galaxies other than our own.   Hubble also has advantages when studying very massive stars. These stars emit large amounts of energetic ultraviolet radiation, which is absorbed by the Earth's atmosphere. From its position above the atmosphere, Hubble can detect ultraviolet light from these massive stars. The Hubble data can then be analyzed and used to characterize the stars' properties.   This Hubble image is a good example of the interaction between gas, dust, and stars. Millions of years ago massive stars in the main cluster exploded as supernovas, forming the spectacular filigree pattern of diffuse gas visible in the image. It is believed that the birth of new stars can be triggered by the enormous forces in the shock fronts where the supernova blast waves hit and compress the gas. The nebulous gas is part of the N103 super bubble and looks similar to the well-known supernova remnant Cygnus Loop in our own Milky Way.   NGC 1850 lies in the southern constellation of Dorado, the Goldfish, sometimes known as the Swordfish. This image was created from five archival exposures obtained with Hubble's Wide Field Planetary Camera 2 between April 3, 1994 and February 6, 1996.  Image Credits: NASA, ESA, and Martino Romaniello (European Southern Observatory, Germany) Acknowledgments: The image processing for this image was done by Martino Romaniello, Richard Hook, Bob Fosbury and the Hubble European Space Agency Information Center.

Constellation Report

Our Constellation Report is an easy way for people to become familiar with the nighttime sky. We’ll discuss myths associated with a particular constellation as well as describing the numerous deep sky objects residing within its boundaries. 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 Bootes the Herdsman. The actual meaning of Bootes is the Ox Driver. But... due to it's proximity to the two bears he is also referred to as the Bear Driver. The constellation Bootes looks much like a kite. To find Bootes, first find it's brightest star, Arcturus. To find Arcturus, return to the Big Dipper. Follow the arc of the Big Dipper's handle to Arcturus. The kite rises from this star.

Deep Sky Report

The focus of our efforts this week will be the deep sky objects of Bootes. First up, we have to mention Alpha Bootes, Arcturus. Arcturus is the 4th brightest star in the sky... and the brightest star north of the celestial equator. Located a mere 37 light years from Earth, it is also one of the closest stars in the sky. Arcturus is estimated to be about 20 million miles in diameter... roughly 25 times the diameter of the Sun. Arcturus is the bright star at the base of the constellation. Epsilon Bootes, also known as Izar, is a beautiful double star made up of a mag 2.5 primary and a mag 5.0 secondary star. The pair have beautifully contrasting colors of yellow and green. Izar is the bright star midway up the left side of the constellation. for 2002. We've added high resolution star charts for all of our deep sky objects. Along with the map of the constellation which we've always had, clicking on any of the deep sky objects will bring up a high resolution star chart centered on that object. Hope this helps.

Ok, let's start things off with Spiral Galaxy NGC5248(mag10.2). This beautiful galaxy has a bright core which you'll instantly see... and some interesting spiral arms... the number of which you see will depend on the size of your telescope and the darkness of your skies. Anything less than about 8" shouldn't expect to see much of the arms... just a haze around a stellar core. From 8" on up...under dark skies... you'll begin to see structure to the arms. As you can see from the accompanying image, even long exposure CCD photographs are still barely resolving some of the fainter arms (top left and right).

Next we'll hit Spiral Galaxy NGC5676(mag10.9).  Don't let this photo fool you. This galaxy compares well with the previous galaxy. It's a little smaller and ends up having a slightly higher surface brightness. So... the amount of detail should be quite similar. You'll notice that this galaxy has no bright stellar core. It's central region is less pronounced, but seems to extend further. The arms also seem to show less structure.

Let's wrap things up with this weeks Utah Skies Challenge Object, Elliptical Galaxy NGC5820(mag11.9).  This ought to be a fun one for you as it's in the middle of a crowded field of galaxies. NGC5820 will be the brightest one in the bunch. As you can see in the image, there is a relatively bright double star just to the side. Also.. if your eyes.. your scope and your skies are good.. you just might make out the faint extension along the southeast edge of the galaxy. 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.

IDA-Utah Light Pollution Update

Checkout the recent CNN article on Light Pollution.  Non-Compliant Merchants What would we do if we discovered a local merchant that sold cigarettes to minors? I'll bet there would be a huge outcry from the public and a quick visit from the sheriff. Would there be prison time or fines levied? Possibly. Would the merchant be forced to close shop? Possibly. What about a merchant that sold alcohol after hours? You can be sure that the Department of Alcohol Beverage Control would fine them and shut them down immediately. Well, what about merchants who sell products which conflict with county ordinances? More specifically, what about a merchant which sells exterior lighting fixtures which did not comply with the county's exterior lighting ordinances? You think that would never happen? Guess again. It happens every single day of the week! And, (probably) more surprisingly... it happens at virtually every retailer that sells outdoor lighting products. Really! I went and paid a visit to several retailers who carry exterior lights. Across the board, the lights on display at each of these merchants did not comply with county lighting ordinances. I'm not talking a couple of lights here.... not even a few... but most. By my estimate, over 95% of the lights on display at these very well known retailers could NOT legally be installed in Summit County! That's right. If you the home or business owner went to one of these stores and bought exterior lights from them and installed them on your home or business.... you just made you property non-compliant. To give you an example of how blatant a violation this is, I went into a vendor looking for good, compliant lights for my home. Not seeing any lights which complied with county codes, I questioned the sales person. He told me that "nobody pays attention to those ordinances anyway". I kid you not. Not that there aren't a wide range of compliant lights available. These merchants simply chose to ignore the law and sell these other styles. So... what are we going to do about this? Should the Sheriff go and close those vendors down or force them to immediately remove all non-compliant fixtures? Should they be fined or jailed? What exactly are we to do when merchants who deliberately choose to ignore the law? Mind you... these are not recent ordinance changes that they haven't yet had time to deal with. These are county ordinances which have been on the books for over five years. Clearly, this is a complete disregard for the law and can not be tolerated. Checkout the IDA-Utah website at www.UtahSkies.org/ida for more information on the harmful effects of improper lighting or for ideas on how to improve your lighting. Please contact us with any questions you may have or to Volunteer to help us in the fight to curb light pollution.

Next Weeks Report

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

 

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