Report for 2001-09-14
Welcome to the Utah Skies Report.
Brought to you from beautiful Park City, "View-tah".
|
|
| We at Utah Skies mourn with America and the other nations of the world the loss of life associated with Tuesday's ugly and cowardly terrorist act. It is somewhat comforting to know that a dark sky and focused gaze can remind us of the infinite beauty that overshadows this ugliness. Utah Skies dedicates this Weekly Report to those no longer with us and the universal beauty that lives on.... |
| Sunrise: 7:06 am | Sunset: 7:39 pm |
| Astronomical Twilight Ends: 5:33 am | Astronomical Twilight Begins: 9:13 pm |
| Moonrise: 3:25 am | Moonset: 6:25 pm |
Star Party
| Yup! We're doin' it again! Utah Skies will be hosting a star party at Park City's Trailside Park on Saturday night September the 22nd from 8:00pm until 1:00am. Our evening will begin with a tour of the solar system. First up will be views of the crescent moon -- then we're off to meet several other residents of our solar system. Mars, Jupiter, Saturn, Uranus, Neptune and maybe even Pluto (if we can find it ;). Don't think for a moment that we'd limit our travels to the solar system. Nope! We'll journey throughout our galaxy and beyond. Star clusters, nebulas and even remote galaxies are on our itinerary -- So, mark your calendar and plan on coming up to party with us! |
Viewing Outlook
| Last weekend and the beginning of this
week were amazingly clear. I got some amazing views of Saturn being
occulted by the moon on Monday morning. It was a bit like the Elephant and
the Flea. In reality, Saturn is the Elephant and the moon the flea.
However, because Saturn is 4000x more distant than the moon, the roles
were reversed. Tiny Saturn looked as if it would fit inside any small to
mid-sized lunar crater. It definitely made an interesting site. Anyway... After a bit of unsettled weather, it looks like we're in for some nice, clear nights. So, if your plans will be taking you to darker skies, make sure to pack your telescope or binoculars. I'm heading down to southern Utah for a few days of hiking the red rocks and a few nights of DEEP sky observing. The skies of southern Utah are among the darkest and clearest on the planet. |
| 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. |
|
| NGC 4013: A Galaxy on the Edge According to the Hubble Heritage team, NASA's Hubble Space Telescope snapped this remarkable view of a perfectly "edge-on" galaxy, NGC 4013. This new Hubble picture reveals with exquisite detail huge clouds of dust and gas extending along, as well as far above, the galaxy's main disk. NGC 4013 is a spiral galaxy, similar to our own Milky Way, lying some 55 million light-years from Earth in the direction of the constellation Ursa Major. Viewed pole-on, it would look like a nearly circular pinwheel, but NGC 4013 happens to be seen edge-on from our vantage point. Even at 55 million light-years, the galaxy is larger than Hubble's field of view, and the image shows only a little more than half of the object, albeit with unprecedented detail. Dark clouds of interstellar dust stand out in the picture because they absorb the light of background stars. Most of the clouds lie in the plane of the galaxy, forming the dark band, about 500 light-years thick, that appears to cut the galaxy in two from upper right to lower left. A similar effect can be seen in our own sky. If one views the Milky Way by going well away from city lights, dust clouds in the disk of our own galaxy appear to split the glowing band of the Milky Way in two. |
 |
Space Weather Update
 |
Sunspot activity is on the rise. Could we have northern
lights in our future? According to spaceweather.com Several bright coronal mass ejections (CMEs) have billowed away from the Sun during the past 24 hours. Most of them have appeared near the solar limb and so were not Earth-directed. Earth's magnetosphere could experience glancing -- or even direct -- blows from these CMEs on Sept. 13th or 14th. |
Lunar
Phase
| We'll be under the new moon Monday
morning. This is my favorite time of the viewing month. The moon doesn't
rise until just before sunrise. And, when it does, it'll be just a
beautiful little crescent moon -- a very cool sight, and posing no major
threat to my deep sky observing. During this phase, the moon will be visible throughout the daylight hours. In fact, there is only a brief portion of darkness which is affected by the moons presence. Go outside and check it out. |
|
Planetary Report
| Mars is rising in the southeast around
3:45 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 12" from 21" in June. Once it gets below 10", we'll
basically be unable to make out any surface detail. Additionally, it has
dimmed significantly as well - currently shining at magnitude
-0.62 down from -2.4 in June. Remember, each magnitude change is a factor
of 2.5 so, a 2 magnitude change is 2.5 * 2.5 = 6.25 times dimmer than it's
peak! Anyway...Mars reaches
its Zenith, or highest point in the sky, around 8:15pm. Best views of the
planet start as soon as you can find it. From my location, I lose
Mars by around 10:30. So, I barely even get to view it under truly dark
skies. I'm already thinking about it's return visit in the summer of 2003.
On that visit, Mars will be closer to Earth than at any point in the last
10,000 years! It will also be better positioned for viewers in the
northern hemisphere. |
|
Saturn joins us now about
11:30pm. Look for Saturn in the
east-northeast. At magnitude 0.03,
Saturn is brighter than any of the stars in that area of the sky. Also,
as the Earth nears Saturn in it's orbit, it continues to grow -- currently
at to 19". Saturn is considerably larger and will soon be brighter than Mars.
Get out there and checkout Saturn. If you've never done so through a telescope, you're in for a big surprise. Those big, beautiful rings will simply amaze you. They're visible in a decent pair of binoculars or basically any telescope you can get your hands on. If you don't have access to a telescope, better plan on attending the upcoming Utah Skies Star Party. You can be sure that there will be several telescopes pointed at Saturn from the moment it rises until we pack up later that night . The accompanying image shows Saturn reappearing from behind the moon. |
| Next, look for Jupiter rising around
1:20am. Jupiter is the king of the Planets. It is more massive than
all the other planets combined. Jupiter is currently shining at mag -2.14 and it has grown to a whopping
37". That's twice the apparent size of Saturn and over 3 times that
of Mars.
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. Watching the orbits of these moons is fascinating. Their motion is quite apparent during an observing session. Transits and shadow transits are the most impressive events. See if you can follow a transiting moons across the surface of Jupiter. This is often more difficult than you'd think. The Earth's turbulent atmosphere often erases the fine detail required to witness these events. However, shadow transits are usually quite easy to view. The dark, inky black shadow of one of the moons typically stands out in stark contrast to the bright surface of Jupiter. The accompanying image shows Io transiting Jupiter.
Also notice the dark spots on the planet. That's Io's shadow. Notice how
sharply the shadow stands out in contrast to Io itself. Shadow transits
are what you'll see most often
|
|
| Venus is the last to arrive on the scene,
rising at about 4:40. While not impressive telescopically, Venus is
stunning to the naked eye. If you're outside prior to the sun rising, make sure to look to the east. You'll see an impressive lineup of planets. |
| 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 Aquarius -- the water-bearer.
|
 |
Deep Sky Report
The focus of our efforts this week will be the deep sky objects of
Aquarius. This constellation is due south around midnight. It is the
next constellation to the north and east of Capricornus, which we covered last
week.
We begin our journey through Aquarius with a visit to Alpha Aquarii(mag2.93). This star has a similar spectrum to our sun. However, it is much larger than our sun. Estimates put it's size at over 80 times the diameter and it's total luminosity at over 6000 times that of our sun. |
Next up is Beta Aquarii(mag 2.86). This star has almost the same total luminosity as Alpha Aquarii, but is located at a slightly smaller distance and hence is slightly brighter. Why is the beta star brighter than the alpha star you may be wondering. Good question. This probably has to do with the fact that less accurate methods were used to determine visual magnitudes when the stars were first cataloged. This may have resulted from Beta's more southerly declination. The Alpha star, being higher in the sky, may have appeared brighter. Modern instruments and techniques have remedied this. |
|
|
Let's start things off with a nice, big
Globular Cluster -- M2(mag6.5). This is a really cool globular. It's big
and bright and at least in the big scope, resolves to many individual
stars. Discovered by Jean-Dominique Maraldi in 1746, M2 is located
some 37,000 light years away and has a diameter of about 150 light-years.
M2 is believed to contain about 150,000 stars, and is one of the richer and more compact globular
clusters. It has a class II designation. This refers to a classification
scheme running from class I (extremely rich and highly compressed) to
class XII (very loose and sparsely clustered).
This cluster is slightly elliptical , as can be seen in the accompanying. Its brightest stars are red and yellow giants of magnitude
13.1 -- these, of course, are not visible in this black and white image :( |
|
Next up is another Globular Cluster M72(mag9.3) This
one is no where near as impressive as it's neighbor to the north. It is
beautiful, but in a much more subtle manner. Discovered 1780 by Messier's
assistant Pierre Mechain,
M72 is one of the more remote of Messier's globular clusters: At an
estimated 53,000 light years, it lies a considerable distance beyond the Galactic Center.
An interesting fact about M72 is that it is one of the most intrinsically luminous globular
clusters. Were it located closer, it would undoubtedly be a deep sky
favorite. Its diameter is approximately 90 light years. |
 |
| Continuing on our journey, we come to a very interesting object, NGC7009, the Saturn Nebula(mag8). This object looks like a pale blue star at low power. |  |
| We'll finish our journey through Aquarius with this weeks double Utah Skies Challenge Objects. Spiral Galaxy NGC 7723(mag11.1) and Barred Spiral Galaxy NGC 7727(mag10.7). We list these objects together due to their close visual proximity. NGC7727 is only about 40' (2/3° ) north of NGC7723. If you find one, you'll most likely find the other -- possibly even at the same instant. Checkout the star chart above. You'll see both objects in the southeastern portion of Aquarius. NGC7723 is not quite as bright as NGC7727. But, it's also not quite as big. So, the light is a bit more concentrated. | |
 |
 |
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.
Next Weeks Report
Next week, we'll continue our journey through the cosmos
and focus on the constellation Pegasus.
|
Stay up to date on astronomical happenings by regularly
checking the Utah Skies website at http://www.UtahSkies.org
|