Report for 2002-04-05
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Welcome to the Utah Skies Report.
Brought to you from beautiful Park City, "View-tah".

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

Astronomical Times

Sunrise: 6:05 am	Sunset: 6:55 pm
Astronomical Twilight Begins: 4:30 am	Astronomical Twilight Ends: 8:30 pm
Moonrise: 2:51 am	Moonset: 12:10 pm

Viewing Outlook

Space Weather Update

Magnetic fields around sunspot 9878 have fluctuated considerably. Astronomers were indicating that powerful X-Class flares could develop from this region. This hasn't happened, but that doesn't mean that there were no aurora. As you can see below, those living in the far north were treated to an incredible light show. This was caused by a fast moving solar wind coming from a coronal hole. I took the pictures below on Saturday(3/30). The large sunspot group (9885) is over 10 Earth diameters across!

Even without an Earth-directed CME, Glen Jewers managed to snap this awesome picture of the northern lights over Nunavut, Canada on April 1st. During times of auroral activity, I regularly think of moving further north... way north. What a cool shot!

Mission Update

The International Space Station will make several passes over the northern Utah this weekend. This is the brightest object in 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 is space. .  The accompanying image shows the ISS cruising several hundred miles above the Earth.

Comet Ikeya-Zhang is pretty close to its absolute brightest right now. At an estimated mag3.8, it is still one of the brightest comets in the last five years or so. It is currently moving away from the Sun. As the comet continues its orbit of the Sun, it is beginning to head back out to the depths of our solar system. It currently visible in both the morning sky and the evening sky. If you have a clear view to the north western horizon, evenings will be your best time to view the comet. If you have a clear view to the north eastern horizon, mornings will be your best time to checkout the comet. How can the comet be visible in the west after sunset... and in the east before sunset??? Good question. The reason is that the comet is now far enough north that it only sets for a little while. Objects which are far enough north are referred to as circumpolar, and never set. The comet is pretty close to that point. It sets for a few hours only to rise again a short while later. In about a week or so, the comet will never set. It will become circumpolar as viewed from mid-northern latitudes. This will 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 got out and viewed the comet on Thursday morning and again on Thursday evening as it cruised by Andromeda. It was pretty sweet. Once I found it (a relatively easy task), I was able to see it with the naked eye. Of course the views in my 10x50 binoculars were far better. Better still was the view through my rich-field refractor. It's 120mm f/5 optics captured enough light to show off the comet, while still allowing a wide enough field of view to see the whole comet AND Andromeda. It was very cool! Finnish Photographer Pekka Parviainen captured this image of the comet and The Andromeda Galaxy on April 1st. This is about what it looked like on the 4th (minus the color). The comets tail seem to stretch forever.

Having trouble finding the comet? Checkout this finder chart and ephemeris page. 

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.

The moon reached last quarter yesterday (4/4). Rising later and later each nigh, the moon interferes less and less with the deep sky observer. We'll take advantage of this fact by giving you a diverse bunch of deep sky treats.  If you're looking to view the moon, you're best bet is just before sunrise... or even after sunrise for that matter. It's certainly the most convenient time :)

I took this image a while back from the Park City area.

The accompanying image was taken by the Voyager 2 spacecraft as it approached the distant planet. The large, dark oval to the left side of the image rotates around the planet in about 18 hours. This image, and many others came from NASA's "Welcome to the Planets" website.

Uranus, the 7th planet, is rising at 4:20am. Shining at mag5.90, 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.

Checkout the rings of Uranus. Yup! Uranus has rings too. They're no where near as bright as Saturn's, but they are there. 

Mercury is rising at about 6:15 am.   It currently spans 5" and is shining at -1.79. Mercury has gotten really bright over the last several weeks. Unfortunately, it is rising shortly after the Sun and is totally washed out by the bright dawn sky.

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.

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".   

Checkout these cool images of the changing phases of Venus by the Maple Ridge Observatory. These were taken using a special Bessel U Filter which allows the transmission of ultra-violet light. Note the detail captured in the clouds of Venus' upper atmosphere.

Mars is rising in the southeast around  7:50 am. 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 1.50 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.

Checkout this sweet image captured by the orbiting Mars Global Surveyor.  Notice how much ice had accumulated at the south polar region.

Saturn joins us now about 8:55 am. Look for Saturn 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 :(   Saturn has currently spanning an an impressive 17" -- this is just shy of it's peak size and is currently shining at magnitude 0.14 -- which is also down a bit 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.   

Checkout this absolutely amazing mage of Saturn as captured by Ed Grafton. This is a very cool shot. Notice the innermost ring. It's called the Crepe ring and it's almost transparent. 

Next, look for Jupiter rising around 10:40am. 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 -2.16 and spans 37". This is off quite a bit from it's peak of 47" earlier this winter... 

Checkout this 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.

 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, the 9th planet, is rising at about 11:30pm. At mag 13.87, 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.

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!

(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.)

This weekend we move on to the constellation Ursa Major. Best known as the "Big Dipper", Ursa Major is the true name of this constellation. The Big Dipper is what astronomers refer to as an asterism. An asterism is a  named grouping of stars which is not officially recognized as a constellation. 

The focus of our efforts this week will be the deep sky objects of Ursa Major. This is such a well known constellation. It is probably familiar to and findable by more people than any other constellation. This is a good thing, since Ursa Major is home to some of the most beautiful and most amazing deep sky objects known. Many of these are easily viewed in amateur telescopes and will be covered below.

Another reason for familiarity with Ursa Major is that two of it's stars, "Merak and Dubhe" are known as the pointer stars. Pointers to Polaris, the "North-Star". Once you learn these stars, you'll always know your directions at night. To find Polaris (and hence, north) start at Merak and draw a line through Dubhe and you'll arrive at Polaris.  

And speaking of a pair of stars. One of the best known double stars is in Ursa Major. Located in the handle of the Big Dipper is Mizar.

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.

Next we'll hit a beautiful Spiral Galaxy M81(mag6.9).  This is an easy target for backyard astronomers. Visible in a decent pair of binoculars, this galaxy comes alive in telescopes. At mag 6.9, this is one of the brighter Messier galaxies. 

This awesome image was taken by Robert Gendler. I've said it before, I'll say it again. Checkout Robert's site. He is one of the most amazing astro-photographers out there. The quality of his work is almost unparalleled. 

Continuing along... a very short distance,  we come to Irregular Galaxy M82(mag8.4). This is one of my favorites. While M81 is brighter, as I increase the magnification, I always tend towards M82. It's slender appearance along with it's somewhat mottled center keeps me coming back for more. 

This is another fine image by Robert Gendler.

Let's backup just a bit and take a look at the pairing of M81 & M82. As you can see, they're pretty close; separated by only about 3/4°.This is the spacing you'd see in a low power field of view in a typical amateur telescope... both objects easily fitting within the eyepiece. 

This awesome shot was taken by.. yup.. you guessed it.. Robert Gendler. Is this guy good or what?

Next we throw a slight curve and visit a sweet Planetary Nebula known as the Owl Nebula, M97(mag9.7). This is one object which really benefits from dark skies and increased aperture. This is an image by Al Kelly.

When viewing this object, most people immediately see a round nebula. Averted vision is typically required for the eyes to become apparent. This is a fun object. At times, it almost appears to be blinking at you. The eyes will open when you're looking with averted vision and then close the instant you look at it directly.

To find "The Owl", simple move about 2° southeast of Merak.

Next up we come to a beautiful Spiral Galaxy M101 & M102(mag7.2). I say A beautiful spiral galaxy because Messier's list incorrectly contained references to this galaxy twice. Oh, well... it is a pretty sweet galaxy :)

Ok... I'll be upfront with you. This object is much harder to view than it's mag 7.2 would suggest. Spanning over 28' in diameter (almost as big as a fulll moon), this galaxy has a surface brightness of over mag14! It's bright, but that brightness is spread way out. You won't have trouble finding it. The difficulty lies in the details. Let me know what you think of this object.

To find this galaxy, I always envision an equilateral triangle above (northeast) of the handle of the dipper. If you're searching at low power (a good idea) this is a close enough approximation to put you on it.

Oh, by the way... this is another Robert Gendler shot.

Continuing on, we come to Spiral Galaxy M108(mag10.1). This... 

To find this object, travel about 1° southeast of Merak. 

Let's back up just a bit for a very interesting pairing of a galaxy and a planetary nebula M97 and M108.
This beautiful rich-field view came from the camera of Jerry Lodriguss. Jerry created this from a single 60 minute exposure through a 130mm Astro-Physics refractor. If you want a really nice telescope, you'd be well served to try to get your hands on one of these. The wait from the factory is measured in years though.

Continuing on, we come to Barred Spiral Galaxy M109(mag9.8). This beautiful image was captured by... yup... Robert Gendler. Truth be told, short of the Hubble Telescope, when Robert has imaged an object, it's hard to find a better one.

To find this beauty, travel about 1° southeast of Phad (Gamma Ursae Majoris) in the base of the dipper.

Let's wrap things up with this weeks Utah Skies Challenge Object, Spiral Galaxy NGC3184(mag9.75). This is yet another beautiful spiral galaxy. The arms on thsi galaxy are perfect. It looks like its doing cartwheels across the sky. Too bad I couldn't find a Robert Gendler image of this baby :)

Anyway... This isn't an incredibly faint object... and there are nearby stars to use for guiding. The closest stars, however, are in the constellation Leo Minor which we covered a few weeks back.

Good Luck!