Report for 2001-10-19

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

Astronomical Times

Sunrise: 7:42 am	Sunset: 6:42 pm
Astronomical Twilight Ends: 6:11 am	Astronomical Twilight Begins: 8:13 pm
Moonrise: 10:57 am	Moonset: 8:53 pm

Star Party Announcement

Utah Skies would like to invite you to attend our next star party. The event will take place under the dark skies of Park City's Trailside Park this Saturday night October the 20th. The party will run from 7:00pm until 1:00am. Checkout our Star Party Itinerary for details of the nights observing schedule and our Trailside Park map for those who need directions. As it will undoubtedly be chilly, please dress appropriately and plan on having a great time

Orionid Meteor Shower

The Orionid meteor shower peaks this weekend. Just in time to be viewed at the star party.  (how convenient :)  The Orionids are named for the constellation from which they appear to emanate or radiate; the point from which the meteors appear to originate is called the radiant.. The meteors are not actually related to the constellation Orion or any of its stars, rather, they are part of the debris trail left by Halley's comet, through which the Earth passes each year. Orionids at their peak typically produce upwards of 25 meteors per hour, though typically 10-20 per hour is average. What in the world is a meteor shower you may be wondering? Well, According to information published by the Martz Observatory: Several times a year the Earth passes through the debris trains left in space by passing comets. The tiny particles of ice and dust collide with the Earth's upper atmosphere at tremendous speeds that cause these tiny missles (often smaller than a sand grain) to heat up to extreme temperatures, causing them to briefly glow brightly as they bore into our planet's increasingly thicker air and burn up. The vast majority of these meteors burn up in just a second or so at altitudes above 60 miles, but a few large ones (perhaps the size of a soccer ball) can put on incredible light shows as the they push deeper into our thick atmosphere and burn up over the space of a several seconds. These "bolides" or "fireballs" often appear to change color, trail "sparks", leave smoke or ionization trails and can even become so bright they cast shadows on the ground. Meteor observing is fun and requires only a dark sky. A reclining lawn chair, binoculars to examine smoke or ionization trails and a perhaps sleeping bag to stay warm are typical meteor observers equipment. Although you'll be able to see meteors or "shooting stars" all night, for most meteor showers the best time to observe the highest number of meteors per hour is in the pre-dawn hours. If you've never seen a meteor shower under a dark country sky, you will be amazed!

Viewing Outlook

Skies have been really good, and really bad over the last week or so. The weekend forecast is calling for clear skies. So, dress warm and get out there and observe.  On a more technical note: Make sure you setup your telescope outside at least 30-60 minutes prior to viewing. This will allow the telescope to come to thermal equilibrium. If your telescope is kept in a cool place, like your unheated garage, then you can probably get by with the shorter cool down period of 30 minutes. If, on the other hand, you store your telescope inside your warm, cozy house, you'll need every one of the 60 minutes for your telescope to adjust to the colder temperatures outside.

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 some of these incredible images, and share some of them with you.

Ghostly Reflections in the Pleiades According to the Hubble Heritage Team, "NASA's Hubble Space Telescope has caught the eerie, wispy tendrils of a dark interstellar cloud being destroyed by the passage of one of the brightest stars in the Pleiades star cluster. Like a flashlight beam shining off the wall of a cave, the star is reflecting light off the surface of pitch black clouds of cold gas laced with dust. These are called reflection nebulae. The famous cluster is easily visible in the evening sky during the winter months as a small grouping of bright blue stars, named after the "Seven Sisters" of Greek mythology. Resembling a small dipper, this star cluster lies in the constellation Taurus at a distance of about 380 light-years from Earth. The unaided eye can discern about half a dozen bright stars in the cluster, but a small telescope will reveal that the Pleiades contains many hundreds of fainter stars.   In many cases, the nebulae surrounding star clusters represent material from which the stars have formed recently. However the Pleiades nebulosity is actually an independent cloud, drifting through the cluster at a relative speed of about 6.8 miles/second (11 kilometers/second).  In the new Hubble image, Merope itself is just outside the frame on the upper right. The colorful rays of light at the upper right, pointing back to the star, are an optical phenomenon produced within the telescope, and are not real. However, the remarkable parallel wisps extending from lower left to upper right are real features, revealed for the first time through Hubble's high-resolution imaging capability.  Astronomers George Herbig and Theodore Simon of the University of Hawaii obtained these broadband observations with Hubble’s Wide Field and Planetary Camera 2 on September 19, 1999. Herbig and Simon propose that, as the Merope Nebula approaches Merope, the strong starlight shining on the dust decelerates the dust particles. Physicists call this phenomenon "radiation pressure."   Smaller dust particles are slowed down more by the radiation pressure than the larger particles. Thus, as the cloud approaches the star, there is a sifting of  particles by size, much like grain thrown in the air to separate wheat from chaff. The nearly straight lines pointing toward Merope are thus streams of larger  particles, continuing on toward the star while the smaller decelerated particles are left behind at the lower left of the picture.    Over the next few thousand years, the nebula--if it survives the close passage without being completely destroyed--will move on past Merope, somewhat like a comet swinging past our Sun. This chance collision allows astronomers to study interstellar material under very rare conditions, and thus learn more about the structure of the dust lying between the stars."

Space Weather Update

According to Spaceweather.com, "Solar activity remains low. However, sunspot 9661, which covers an area of the Sun equal to the total surface area of four planet Earths, has a twisted delta-class magnetic field that could unleash M- or X-class solar flares during the days ahead."

Aurora Update

All's quite on the aurora front lately. But, that could change. As the space weather update shows, there are several large sunspot groups which are threatening to unleash a barrage of CME's in our direction. Let's hope so :) The accompanying image by Chris VenHaus of Eau Claire, Wisconsin clearly show us what we've been missing.

Lunar Phase

The moon was new this past Tuesday. As such, it will be setting shortly after sunset. So, we'll have lots of time (and dark sky) to find our deep sky favorites. The moon, however, is at its best for observing. Sporting a small crescent phase, it'll offer up subtle details which would be invisible during the full phase -- check it out! The accompanying image, created by photographs taken by the Mariner 10 spacecraft  in 1973 reveals the relative sizes of the Earth and Moon. The moon has a diameter of about 1/4 that of the Earth.

Planetary Report

Mars is rising in the southeast around  3:05 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 decreased in apparent size down to a measly 10" as compared to its 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 -0.2 down from -2.4 in June.

Saturn joins us now about 9:10 pm. Look for Saturn in the east-northeast. Saturn has grown to an an impressive 20" and currently shines at magnitude -0.17.  I took the accompanying image of the moon getting ready to occult Saturn in early September 2001. Notice the illusion of size. Here the moon looks many times larger than Saturn. In reality, Saturn is many times larger than the moon. It is however 4000 times further away, leading to the illusion of being smaller.

Next, look for Jupiter rising around  11:15pm. Jupiter is the king of the Planets. It is more massive than all the other planets combined. Jupiter is currently shining at mag -2.36 and it covers a whopping 41". You definitely need to add Jupiter to your list of regular viewing targets again. It is a very impressive sight in any telescope. Jupiter can even be quite dynamic. Astronomers often watch the changing patterns of its moons as they transit and are occulted by the giant planet. 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 Jovian moons. It's called JavaJup. I regularly refer to JavaJup to help plan my viewing sessions.   The accompanying image of Jupiter's icy moon Europa taken by the Galileo spacecraft shows the scarred surface of the frozen world. Astronomers speculate that these long running marks are cracks in the surface layer of ice -- much like you'd see here on a frozen lake.

Venus is the last to arrive on the scene, rising at about 6:00 am. While still the brightest planet in the sky at mag -3.94, Venus is now rising close to sunrise and has definitely lost some of its brilliance. Notice that I emphasized the word some. I see Venus frequently in the morning sky and it still looks quite impressive. If you're out before the sunrise, which is coming later and later, take a glance to the east. You'll see Venus blazing away.

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 boundarys. 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 Andromeda.  Andromeda was  the daughter of King Cepheus and Queen Cassiopeia of Ethiopia. When Cassiopeia boasted that Andromeda's beauty exceeded that of the sea nymphs, the nymphs prevailed upon Neptune, the god of the sea, to punish Cassiopeia. Neptune sent the sea monster Cetus (sometimes known more favorably as simply a whale) to ravage the kingdom of Cepheus. When Cepheus consulted an oracle for advice, he was informed that only the sacrifice of Andromeda to Cetus the Sea Monster would appease the gods. Thus chained to a rocky cliff, she was rescued by Perseus, who turned Cetus into stone by flashing the face of Medusa before the monster's eyes. Perseus was carried there just in time by the winged horse Pegasus.

Deep Sky Report

The focus of our efforts this week will be the deep sky objects of Andromeda. To find Andromeda, face towards the south east after dark and look up high... almost overhead. You'll quickly see the great square of Pegasus, which we looked at a couple of weeks ago. The northeastern star of the great square is actually the beginning of Andromeda which stretches north and east from there.

 

Ok, let's start things off the biggest and baddest galaxy visible in northern skies, M31 The Andromeda Galaxy(mag3.47). There are so many superlatives which are fitting for Andromeda that I almost don't know where to start. Andromeda lies some 2.3 million light years distant, making it the nearest major galaxy to our own. It is also the most distant object visible to the naked eye. The two small fuzzy objects also visible in this image are actually galaxies. They are M32 and M110. We'll get to these galaxies shortly. Astronomers estimate the mass of Andromeda at over 300 billion suns. This is almost twice as massive as our own Milky Way galaxy. Additionally, it spans over 130,000 light years or roughly 3° -- nearly 6 times the diameter of the full moon! Andromeda is visible in virtually any telescope or binoculars. In larger telescopes, it displays one or more prominent dust lanes. I've spent a considerable amount of time enjoying Andromeda. It is a site to behold in the ObDob. The bright patch on the left side of the image is actually NGC206 -- a bright star cloud in Andromeda itself. We'll be all over Andromeda at the next Utah Skies Star Party!

Next up is a neighbor of Andromeda M32(mag8.2). M32 is what is known as a dwarf elliptical galaxy. Not exactly something one would aspire to :) M32 requires a substantial amount of magnification to reveal any detail. At low powers it is simply a soft fuzzy circular patch that almost appears to be an appendage to M31.

Still in the same low power field of view, we have Elliptical Galaxy M110(mag8.0). Throw some magnification at this object and you'll be rewarded with some fine details. It has a mottled core which is caused by an irregular clumping of stars. Were this object anywhere else in the sky it would get much more attention. Located, as it is, in the same field of view as the giant Andromeda galaxy causes it to be virtually overlooked. I know I am guilty of such neglect. Curiously, this galaxy was discovered by Charles Messier on August 10, 1773, and depicted on his fine drawing of the "Great Andromeda Nebula" and its companions  published in 1807, but Messier did never himself include this object in his catalog, due to unknown reasons, perhaps a certain sloppiness in recording. It was the last additional object, added finally by Kenneth Glyn Jones in 1966. Independent of Messier's discovery, Caroline Herschel discovered M110 on August 27, 1783, little more than 10 years after Messier, and William Herschel numbered it H V.18 when he cataloged it on October 5, 1784.  M110 is about the same distance as the Andromeda galaxy M31, roughly 2.9 million light years. It's mass is estimated to be between 3.6 and 15 billion solar masses.

Next up is NGC7662(mag8.6), The Blue Snowball Nebula. This interesting little planetary nebula is reported to be visible in a good pair of binoculars. In an 8" telescope, it appears as a circular blue patch. In larger apertures, it begins to turn an aquamarine shade. This is an object that definitely handles increased magnification well. The more power you throw at it, the more detail it reveals. Who says (observational) astronomy is black and white?

Next, check out Open Star Cluster NGC752(mag5.7). This beautiful open cluster spans almost a full degree in diameter. It appears as a loose grouping of over 60 stars in telescopes in the 6-8" range. Located only 1200 light years away, this very old cluster is almost 2 billion years old.

Our final stop in Andromeda leads us to this weeks Utah Skies Challenge Object, Edge-on Galaxy NGC891(mag10). This is one of the fines examples of an edge-on galaxy -- definitely one of my favorites. It is a small cigar-shaped galaxy with a beautiful dust lane running through its center. Located about 3.5* east of Gamma Andromeda, this beauty is clearly visible in an 8" telescope. With increased magnification and averted vision, you can begin to make out the dust lane. In larger instruments under dark skies, the views are amazing. Current estimates place its distance at around 31 million light years. This object will definitely be a target at Saturday nights Utah Skies Star Party.

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!

Utah Skies recently participated in The Utah Science Council's "Science and Society" forum sponsored by KCPW. The focus of this gathering was to discuss energy usage and conservation methods. We were quick to draw attention to the fact that the US wastes in excess of $2 billion annually in light pollution alone. Adding this to the fact that many well designed and implemented lighting schemes are simply on too many hours each day and the true scope of energy waste was impossible to ignore..   Take a look at this satellite image and it's obvious that light pollution has become a serious problem throughout the world — 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. But, don't lose hope. Light pollution is easily cleaned up. All we need to do is act intelligently. Here are a coupe of principles to keep in mind: 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 Pisces. 

 

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

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