Cherry Springs
Another month, another visit to Cherry Springs State Park to observe the night skies. As you may recall from my post from June 2nd, the state park is an ideal location for night sky observing, due to the lack of light pollution. The suburban settings outside of Philadelphia, though acceptable for observing the planets and the brightest of stars, is never the correct environment to point a telescope at distant objects -- nebulas, galaxies, globular clusters, etc. To fully appreciate the hobby, one must travel beyond the reaches of all sources of light pollution. And to those living in or around Pennsylvania, Cherry Springs is a great option.
On July 8th, my dad and I traveled to Cherry Springs to get another chance to observe the best starry skies of Pennsylvania. Though normally we bring along our 4-inch TeleVue refractor or our 10-inch Meade Schmidt-Cassegrain, we decided to borrow an 8-inch Orion go-to Dobsonian. We wanted to visit the park earlier, although weather conditions were unfavorable on weekends prior to July 8th. And yes, the work week also gets in the way of such trips....
One important tip for new astronomers everywhere: pay close attention to the details of the weather forecasts! Why you ask? Although the meteorologists were right in forecasting clear skies, we did have some minor degree of cloud cover and, of all things, a boatload of dew. While dew becomes an issue during the night, our scope was covered in dew before sunset, much to our surprise. Our tent, our eyepieces bag, even our chairs were covered in dew. The moisture made aligning the scope a problem. Though we've used the red dot finder while aligning the Dobsonian, we soon realized the moisture had made our red dot finder a red blob projector.
Though we had some cloud cover initially, this was before and slightly after sunset -- no problem there. Around midnight, however, clouds began filling up the skies to the southeast. Did I forget to mention we had the Earth's moon to worry about as well? When adding the moon into this equation, we were observing through milky skies.
Log Cabin Inn
The astronomer cannot live on the dark skies alone; an astronomer has got to eat, right? Personally, I recommend the Log Cabin Inn, located on US Route 6 about thirty minutes east from Cherry Springs State Park.
The menu had an astonishing selection of dishes listed -- all in four pages. The second page (I'm skipping the first page, which covered appetizers) lists various steaks and related meats. Page three covers various freshwater fish and seafood dishes. And the final page covers numerous pasta dishes.
The salad bar -- everything so fresh and nutritious; I helped myself to some homemade macaroni salad and coleslaw, both having such a delightful taste. I swear, I could have gone up for more had I decided to skip the deserts after the main course. Yet, perhaps the best part of the salad bar was the homemade clam chowder. Unlike most eateries in Pennsylvania, this restaurant made their chowder with fresh, tender clams.
Of the items on the menu, I went with their broiled trout, with cheesy mashed potatoes as my side dish. And this wasn't just your average trout purchased at the grocery store; this was freshly caught trout from the local streams.
As for deserts, there were twelve different deserts to chose from: carrot cake, cheese cake, cheese cake with a carrot cake inside of it, pie, etc. I had settled for a cheese cake that had a carrot cake inside of it; a unique combination, I thought. Already I knew I enjoyed cheese cakes and carrot cakes separately, but together as one desert, that was something worth trying. Mmm ... a lovely cheese cake, carrot cake mixture it was! I could have it again and again.
How would I rate this restaurant in comparison to others? Personally, I hate to rate everyone; it's too much pressure on my part. Still, it beats eating at a pizza joint. So, fellow astronomers, if you're planning to go to Cherry Springs State Park anytime soon, please take my advise: go to the Log Cabin Inn! I'm sure you'll be satisfied!
Thursday, July 14, 2011
Thursday, June 23, 2011
Taking a Telescope to College--Part 1
To astronomy majors, taking a telescope with them to college may be required or encouraged by college faculty. It would make sense, right? After all, they study the night skies frequently, and it wouldn't be complete without a telescope. To a creative writing major, myself included, that's a different story entirely.
If the creative writing major were to emphasize their writing -- fiction or non-fiction -- on the subjects of astronomy and/or telescopes, then the creative writing major might consider bringing a telescope along. Being a science fiction writer emphasizing the subjects of space travel and the colonization of space and other planets, I have considered purchasing a telescope and bringing it along to Susquehanna University. It certainly would provide the needed inspiration to write science fiction pieces.
Before purchasing a telescope and bringing it along to college, various factors must be considered: the size of the scope, the value, viable targets, and manual or go-to scopes.
Size -- Will a telescope fit in the dorm?
Remember, college dorms are not spacious enough to hold a mammoth telescope. The typical dorm has only enough room to hold two beds, desks, computers, and dressers, one mini-fridge, printer, etc. Naturally these restrictive living quarters allow room for storing other essential belongings, though not enough for items necessary for various extracurricular activities, that includes astronomy.
During my first two semesters at Susquehanna University, there was only enough of room to store a camera, tripod, and a few flying discs (or frisbees) safely. The tight living quarters wasn't appropriate for storing a good-sized telescope, 10" or greater. However, there was enough room for a small dobsonian (8"), refractor (4"), or reflector.
Value -- How much money to risk if the telescope is damaged or stolen?
Even in the college environment, there is the possibility of property being damaged or stolen. Both concerns are, without a doubt, extremely serious to the astronomer.
Who would want to observe through a telescope with an observable scratch in the field-of-view? To me, and other astronomers, the answer is simple: it would be one annoying distraction! Damaging a telescope isn't rocket science. Even a slight bump against a mount or optical tube can knock one over, depending on its size and weight. In college environments, rooms within a dorm are compact, leaving very little space to walk around and higher risks of a telescope being knocked over. Additionally, if the astronomer doesn't properly cover up the optics of their scope, roommates, neighbors, and visitors could potentially scratch the optics. Scratching optics doesn't require much effort; even a shirt sleeve can scratch the lens of an eyepiece or the mirror of a telescope. With those thoughts in consideration, it would be best to keep a telescope in a corner of the room, preferably in a corner that cannot be seen easily.
When at college and storing expensive pieces of equipment -- including computers, cameras, telescopes, etc -- in your room, always assume that someone's going to want to steal your property. Telescopes are not cheap; most people are aware that telescopes are not at all cheap.
Deciding based on previous concerns:
Combing the issues relating to a telescope's size and value, this is where some astronomers, myself included, would stop and speculate over. One way of seeing these thoughts suggests that a large telescope would work best -- the larger the scope, the more difficult it would be for someone to steal it. However, a larger scope would require space that would otherwise be unavailable, due to the presence of furniture, computers and accessories, etc. In addition, the mammoth size of larger scopes would prove difficult to set up for college astronomers, mostly due to the increased weight of the scope.
Although smaller telescopes are at the disadvantage of being stolen, the advantages can outweigh that concern. A small telescope can easily fit into a tight dorm room without overlapping the various objects that may already occupy the room. The decreased size also assists the college astronomer in the initial setup, due to its decreased weight.
What do I suggest? To college students, I suggest small telescopes -- nothing bigger than a 4" refractor to say the least.
Viable Targets -- What can be seen from campus, and how much telescope is needed to see them?
The first question any astronomer must ask: what am I interested in observing?
This factor can alter which telescope the college astronomer may settle for. Not all telescopes are designed to see the same distances. For example, a 4" refractor is typically designed for observing close objects, such as the planets, the moon, and the brightest of stars. Schmidt-cassegrains are designed for observing the planets, the moon, the stars, nebulas, globular clusters, galaxies, and more. Dobsonians are designed for observing distant objects, such as nebulas, globular clusters, galaxies (near and far), and more.
Among the options above, I am stuck between refractors and dobsonians. Although I have observed the planets of Venus, Mars, Jupiter, and Saturn time and again, the Solar System doesn't have what I'm searching for. Personally, my interests in astronomy direct me toward objects beyond the Solar System -- the Andromeda Galaxy being my favorite night sky object.
Another important question to ask: what can I see from here?
As I had mentioned in a previous blog, light pollution can drastically affect an astronomer's ability to observe the night skies. The more artificial lighting surrounding the astronomer, fewer stars will be observable to the naked eye or through a telescope. Compare the city of Philadelphia with Susquehanna University and Cherry Springs State Park:
Manual vs. Go-To -- Should I learn the sky or go for quick looks?
Oh, decisions, decisions! Manual or Go-To scope -- that is the question.
A manually operated telescope requires the astronomer to manually align his/her scope to whatever object they wish to observe. Such a scope is ideal for astronomers who have the desire to learn the skies through hands-on experience. Unlike the Go-To models, however, most manually operated telescopes today do not have tracking devices, resulting in objects drifting out of the field-of-view. If it's desired to track the object, the astronomer is therefore required to manually track the object -- a difficult task, yes, but not impossible.
Go-To telescopes, unlike the manually operated counterparts, require astronomers to utilize a controller to move the optical tube around. There are various ways an astronomer can point to an object with this type of telescope, the simplest way being the use of directional keys to move the optical tube.
Another method is to key in a certain object. The astronomer is required to know what the object's numerical identification is before keying it into the controller. One example of an object and its numerical identification is the Orion Nebula, which is alternatively identified as M42. Once an input is keyed into the controller, and after commanding the scope to align with the object, the scope will automatically go to the desired object. A few minor adjustments may be required afterward; even the most accurate of Go-To scopes are not 100% accurate. If this method of observing the skies is used, the telescope must first be aligned, using three stars in different portions of the sky.
Although the Go-To telescopes are primarily designed to operate with computerized controls, gears, etc., some Go-To scopes are also designed to operate manually. However, manual operations of these Go-To scopes share the same disadvantage as manually operated scopes -- tracking objects would require the astronomer to manually move the optical tube.
Personally, I had the desire for a manual scope that could track objects automatically, yet such telescopes are becoming rare. It was my intention to learn the night skies while being able to stick to one particular object for an extended duration of time. Under that circumstance, I am considering a Go-To telescope.
Final Decisions:
Combining the numerous thoughts and concerns, I'm looking into taking a small Go-To refractor or reflector to Susquehanna University. In time, if the small refractor or reflector expand my interest in astronomy, I may consider getting a small solar telescope and observe the Sun....
If the creative writing major were to emphasize their writing -- fiction or non-fiction -- on the subjects of astronomy and/or telescopes, then the creative writing major might consider bringing a telescope along. Being a science fiction writer emphasizing the subjects of space travel and the colonization of space and other planets, I have considered purchasing a telescope and bringing it along to Susquehanna University. It certainly would provide the needed inspiration to write science fiction pieces.
Before purchasing a telescope and bringing it along to college, various factors must be considered: the size of the scope, the value, viable targets, and manual or go-to scopes.
Size -- Will a telescope fit in the dorm?
Remember, college dorms are not spacious enough to hold a mammoth telescope. The typical dorm has only enough room to hold two beds, desks, computers, and dressers, one mini-fridge, printer, etc. Naturally these restrictive living quarters allow room for storing other essential belongings, though not enough for items necessary for various extracurricular activities, that includes astronomy.
During my first two semesters at Susquehanna University, there was only enough of room to store a camera, tripod, and a few flying discs (or frisbees) safely. The tight living quarters wasn't appropriate for storing a good-sized telescope, 10" or greater. However, there was enough room for a small dobsonian (8"), refractor (4"), or reflector.
Value -- How much money to risk if the telescope is damaged or stolen?
Even in the college environment, there is the possibility of property being damaged or stolen. Both concerns are, without a doubt, extremely serious to the astronomer.
Who would want to observe through a telescope with an observable scratch in the field-of-view? To me, and other astronomers, the answer is simple: it would be one annoying distraction! Damaging a telescope isn't rocket science. Even a slight bump against a mount or optical tube can knock one over, depending on its size and weight. In college environments, rooms within a dorm are compact, leaving very little space to walk around and higher risks of a telescope being knocked over. Additionally, if the astronomer doesn't properly cover up the optics of their scope, roommates, neighbors, and visitors could potentially scratch the optics. Scratching optics doesn't require much effort; even a shirt sleeve can scratch the lens of an eyepiece or the mirror of a telescope. With those thoughts in consideration, it would be best to keep a telescope in a corner of the room, preferably in a corner that cannot be seen easily.
When at college and storing expensive pieces of equipment -- including computers, cameras, telescopes, etc -- in your room, always assume that someone's going to want to steal your property. Telescopes are not cheap; most people are aware that telescopes are not at all cheap.
Deciding based on previous concerns:
Combing the issues relating to a telescope's size and value, this is where some astronomers, myself included, would stop and speculate over. One way of seeing these thoughts suggests that a large telescope would work best -- the larger the scope, the more difficult it would be for someone to steal it. However, a larger scope would require space that would otherwise be unavailable, due to the presence of furniture, computers and accessories, etc. In addition, the mammoth size of larger scopes would prove difficult to set up for college astronomers, mostly due to the increased weight of the scope.
Although smaller telescopes are at the disadvantage of being stolen, the advantages can outweigh that concern. A small telescope can easily fit into a tight dorm room without overlapping the various objects that may already occupy the room. The decreased size also assists the college astronomer in the initial setup, due to its decreased weight.
What do I suggest? To college students, I suggest small telescopes -- nothing bigger than a 4" refractor to say the least.
Viable Targets -- What can be seen from campus, and how much telescope is needed to see them?
The first question any astronomer must ask: what am I interested in observing?
This factor can alter which telescope the college astronomer may settle for. Not all telescopes are designed to see the same distances. For example, a 4" refractor is typically designed for observing close objects, such as the planets, the moon, and the brightest of stars. Schmidt-cassegrains are designed for observing the planets, the moon, the stars, nebulas, globular clusters, galaxies, and more. Dobsonians are designed for observing distant objects, such as nebulas, globular clusters, galaxies (near and far), and more.
Among the options above, I am stuck between refractors and dobsonians. Although I have observed the planets of Venus, Mars, Jupiter, and Saturn time and again, the Solar System doesn't have what I'm searching for. Personally, my interests in astronomy direct me toward objects beyond the Solar System -- the Andromeda Galaxy being my favorite night sky object.
Another important question to ask: what can I see from here?
As I had mentioned in a previous blog, light pollution can drastically affect an astronomer's ability to observe the night skies. The more artificial lighting surrounding the astronomer, fewer stars will be observable to the naked eye or through a telescope. Compare the city of Philadelphia with Susquehanna University and Cherry Springs State Park:
- Philadelphia -- the night sky is illuminated by reflecting lights from skyscrapers, houses, supermarkets, cars, etc. Only a few bright stars and the planets can be seen.
- Susquehanna University -- though the skies are illuminated toward the east by residential communities, by strip malls to the north, and throughout the campus by streetlights and buildings, the skies toward the west provide some degree of relief. The planets and several constellations can be seen.
- Cherry Springs State Park -- little to no light pollution affects the skies here, resulting in night skies filled with thousands of observable stars, and many other objects (planets, galaxies, globular clusters, nebulas, etc.)
Manual vs. Go-To -- Should I learn the sky or go for quick looks?
Oh, decisions, decisions! Manual or Go-To scope -- that is the question.
A manually operated telescope requires the astronomer to manually align his/her scope to whatever object they wish to observe. Such a scope is ideal for astronomers who have the desire to learn the skies through hands-on experience. Unlike the Go-To models, however, most manually operated telescopes today do not have tracking devices, resulting in objects drifting out of the field-of-view. If it's desired to track the object, the astronomer is therefore required to manually track the object -- a difficult task, yes, but not impossible.
Go-To telescopes, unlike the manually operated counterparts, require astronomers to utilize a controller to move the optical tube around. There are various ways an astronomer can point to an object with this type of telescope, the simplest way being the use of directional keys to move the optical tube.
Another method is to key in a certain object. The astronomer is required to know what the object's numerical identification is before keying it into the controller. One example of an object and its numerical identification is the Orion Nebula, which is alternatively identified as M42. Once an input is keyed into the controller, and after commanding the scope to align with the object, the scope will automatically go to the desired object. A few minor adjustments may be required afterward; even the most accurate of Go-To scopes are not 100% accurate. If this method of observing the skies is used, the telescope must first be aligned, using three stars in different portions of the sky.
Although the Go-To telescopes are primarily designed to operate with computerized controls, gears, etc., some Go-To scopes are also designed to operate manually. However, manual operations of these Go-To scopes share the same disadvantage as manually operated scopes -- tracking objects would require the astronomer to manually move the optical tube.
Personally, I had the desire for a manual scope that could track objects automatically, yet such telescopes are becoming rare. It was my intention to learn the night skies while being able to stick to one particular object for an extended duration of time. Under that circumstance, I am considering a Go-To telescope.
Final Decisions:
Combining the numerous thoughts and concerns, I'm looking into taking a small Go-To refractor or reflector to Susquehanna University. In time, if the small refractor or reflector expand my interest in astronomy, I may consider getting a small solar telescope and observe the Sun....
Thursday, June 2, 2011
Cherry Springs State Park--Part 1
Appreciating the night skies has become a dieing habit. Most beginning astronomers begin the hobby using their suburban homes as their observation sites. Astronomers will become familiar with unforgettable constellations (the Big and Little Dippers, Leo the Lion, Orion the hunter, Taurus the Bull, etc.), in addition to the brightest stars (Sirius, Vega, etc.) and the planets. However, given enough time, wouldn't the astronomer become bored observing the same objects every time he/she had a chance? Personally, I did; the planets, brightest stars, and unforgettable constellations were not enough to satisfy me.
Though the brightest of stars, the planets, the moon, and (on rare occasions) artificial satellites and the International Space Station are observable, the greatest of the heavenly treasures -- faint stars, nebulas, star clusters, and galaxies -- are faded out, due to various sources of light pollution. Suburban settings, even thirty miles outside of Philadelphia, are an astronomer's worst nightmare; Walmarts, Kmarts, Home Depots -- in short, Big Box Marts -- and every household generating blinding levels of light pollution. To fully appreciate the night skies, it is necessary to eliminate all the artificial lighting. Of course, that raises the question: who's going to turn off their lights? The answer is simple: very few are willing to turn off their lights. Is it a fear of the dark; a sense of security; or merely, an act of human nature -- wasting energy and resources? Whatever the reason, astronomers (amateurs and professionals) are left with very few options. I have taken an approach most amateurs and professionals take -- pack up and travel where light pollution doesn't affect the skies.
Starting in 2002, my dad and I spent a few nights observing from a site dedicated to astronomers -- Cherry Springs State Park. The site is located approximately 60 miles northwest from Williamsport, PA, and at least 14 miles southeast from the nearest town of significant size, Coudersport, PA. These distances separating the park from suburban and urban districts make it an ideal location to properly observe the starry skies. Unlike the suburbs, where the average astronomer could pick out 50 stars, navigating the starry skies at Cherry Springs can become a challenge to new astronomers. Thousands of stars fill up the night skies at Cherry Springs, creating what many can consider an astronomer's paradise. I'll admit it, with thousands of stars filling up the sky, picking out the constellations was overwhelming!
As the skies continue to darken, with each passing minute, the galactic core and plain of the Milky Way brighten up. Locating constellations along the Milky Way, such as Cygnus the Swan, add to the already overwhelming difficulty, due to the increasing number of stars. However, this difficulty adds to the enjoyment. The spaces surrounding the galactic core are occupied by various globular clusters and nebulas, such as the M22 globular cluster and the Trifid and Lagoon nebulas.
Although the Milky Way Galaxy hosts a great variety of objects to observe, I personally prefer extending out to the intergalactic spaces. Under this scenario, a telescope would be most helpful, especially when observing galaxies that are 3+ million light years from Earth. My favorite galaxy happens to be a close neighbor to the Milky Way -- the Andromeda Galaxy. Located 2.4 million light-years from Earth, the galaxy, as several astronomers have told me, can be seen with the unaided eye. Personally, I cannot see the Andromeda Galaxy without a telescope; I'll resort to using my dad's 4-inch TeleVue refractor or his 10-inch Meade schmidt-cassegrain just to observe the galaxy.
My top favorite observation at Cherry Springs occurred during the Black Forest Star Party in September of 2002. Though I had decided I had enough fun for one night, one event changed everything. Around midnight, many astronomers started shouting, "Look to the north!" Sure enough, brightly lighting up the northern skies in bands of red and green, everyone at Cherry Springs was treated to an Aurora. Remarkably, no one knew that an Aurora was to occur that night.
Stay tuned for Cherry Springs State Park -- Part 2 ...
Though the brightest of stars, the planets, the moon, and (on rare occasions) artificial satellites and the International Space Station are observable, the greatest of the heavenly treasures -- faint stars, nebulas, star clusters, and galaxies -- are faded out, due to various sources of light pollution. Suburban settings, even thirty miles outside of Philadelphia, are an astronomer's worst nightmare; Walmarts, Kmarts, Home Depots -- in short, Big Box Marts -- and every household generating blinding levels of light pollution. To fully appreciate the night skies, it is necessary to eliminate all the artificial lighting. Of course, that raises the question: who's going to turn off their lights? The answer is simple: very few are willing to turn off their lights. Is it a fear of the dark; a sense of security; or merely, an act of human nature -- wasting energy and resources? Whatever the reason, astronomers (amateurs and professionals) are left with very few options. I have taken an approach most amateurs and professionals take -- pack up and travel where light pollution doesn't affect the skies.
Starting in 2002, my dad and I spent a few nights observing from a site dedicated to astronomers -- Cherry Springs State Park. The site is located approximately 60 miles northwest from Williamsport, PA, and at least 14 miles southeast from the nearest town of significant size, Coudersport, PA. These distances separating the park from suburban and urban districts make it an ideal location to properly observe the starry skies. Unlike the suburbs, where the average astronomer could pick out 50 stars, navigating the starry skies at Cherry Springs can become a challenge to new astronomers. Thousands of stars fill up the night skies at Cherry Springs, creating what many can consider an astronomer's paradise. I'll admit it, with thousands of stars filling up the sky, picking out the constellations was overwhelming!
As the skies continue to darken, with each passing minute, the galactic core and plain of the Milky Way brighten up. Locating constellations along the Milky Way, such as Cygnus the Swan, add to the already overwhelming difficulty, due to the increasing number of stars. However, this difficulty adds to the enjoyment. The spaces surrounding the galactic core are occupied by various globular clusters and nebulas, such as the M22 globular cluster and the Trifid and Lagoon nebulas.
Although the Milky Way Galaxy hosts a great variety of objects to observe, I personally prefer extending out to the intergalactic spaces. Under this scenario, a telescope would be most helpful, especially when observing galaxies that are 3+ million light years from Earth. My favorite galaxy happens to be a close neighbor to the Milky Way -- the Andromeda Galaxy. Located 2.4 million light-years from Earth, the galaxy, as several astronomers have told me, can be seen with the unaided eye. Personally, I cannot see the Andromeda Galaxy without a telescope; I'll resort to using my dad's 4-inch TeleVue refractor or his 10-inch Meade schmidt-cassegrain just to observe the galaxy.
My top favorite observation at Cherry Springs occurred during the Black Forest Star Party in September of 2002. Though I had decided I had enough fun for one night, one event changed everything. Around midnight, many astronomers started shouting, "Look to the north!" Sure enough, brightly lighting up the northern skies in bands of red and green, everyone at Cherry Springs was treated to an Aurora. Remarkably, no one knew that an Aurora was to occur that night.
Stay tuned for Cherry Springs State Park -- Part 2 ...
Wednesday, May 25, 2011
Product Review: Orion XT8g Dobsonian Telescope
The Dobsonian Telescopes of the Orion brand clearly rise above all others. Regardless of whether it being a Skyquest Classic or an Intelliscope, the Orion Dobsonians offer great value for the dollar. Over the years, however, rumors relating to a Go-To version of these scopes have circulated. This was due, in part, by the availability of such scopes outside the US. In April of 2010, Orion Telescopes and Binoculars announced the availability of the XTg series Go-To Dobsonians, models ranging from 8-12 inches in aperture and priced between $850 and $1,600.
Similar to all Dobsonian Telescopes, the Orion XTg requires some degree of assembly. It was initially assumed that drive motors would require mounting and setting the gear lash would be necessary for the scope to operate properly. When considering the XTg, however, all motors, encoders, and gears arrive pre-assembled and is easier to assemble than the Intelliscope models. Confident in assembling furniture from Ikea or turning screw drivers? If so, the Orion XTg should be no trouble whatsoever.
The XT8g on Paper
The optical tube assembly of the Orion XT8g is similar to the XT8 Classic -- with a focal length of 1200 mm and a focal ratio of f/6. The scope includes an EZ Finder II reflex finder comparable to the Classic models. Right angle finders, such as the 9x50 found on Intelliscope models, shouldn't be necessary for the XTg series. Also included is the two-speed Crayford focuser found on the XX12i and XX14i models.
Two eyepieces are supplied with the XT8g -- the 28 mm Orion Deep View and the 12.5 mm illuminated reticle eyepiece. The 28 mm Orion Deep View eyepiece features 20 mm of eye relief and a 56 degree apparent field. Yielding 43x magnification and approximately 1.3 degrees of true field, this eyepiece serves as a good finder eyepiece with, possibly, the lowest power usable with this telescope. While aligning the go-to function of the scope, Orion recommends using the 12.5 mm illuminated eyepiece.
One significant difference to this scope in comparison to the Intelliscope series, other than the motors, is the additional weight. Although Orion published the weights of the XT8g and the XT8 Intelliscope bases at 32.7 pounds and 21.3 pounds respectively, the XT8g -- the keypad and power cord included -- weighs approximately 39 pounds. In spite of this increase in weight, this scope is still easily manageable for most people.
Two Dobs in One!
While Orion advertises the XTg series as a go-to telescope brand, which it is, the telescopes can also be operated manually. Even when operated manually, these scopes will track whatever they are pointed at. Orion incorporated a clutch-free design, allowing the telescope to be pushed to any object desired. The scope will then track that specific target. Such features make this scope unique to most go-to telescopes, which require the drive motors or the releasing of the clutch to move. In the latter circumstance, altazimuth mounted scopes lose their ability to track. This is not the case with an Orion XTg, however. The optical encoders operate independently from the motors.
SynScan AZ Controller
The SynScan controller, found on Orion Atlas and Sirius mounts, supports altazimuth operations with the XTg scopes, as opposed to the equiatorial operations used by the Atlas and Sirius mounts. However, the software is functionally the same. Included with the controller is a massive database of 42,900 objects, including those in the Messier and Caldwell catalogs, 7,840 NCG objects, 5,386 IC objects, the moon, planets, and more. Although Pluto is not a planet, it is included in the controller as a planet. Pluto is really a dwarf planet.
The SynScan controller may be updated using an on-board serial port. Although a USB port would be desirable, most telescope mounts today still rely on serial communications. Unlike most other telescopes and/or mounts, which are required to be turned on while receiving updates, the SynScan controller is equipped with a built-in 12-volt DC power port, allowing software updates while disconnected from the mount. Anyone who has ever had to carry an entire telescope or mount to their desktop computer for a software update is sure to appreciate this feature.
The SynScan controller offers three tracking rates, sidereal, lunar and solar, as well as ten slew rates. These slew rates vary from 1x to 1000x sidereal rate, or a maximum of over four degrees per second. That latter number defines the maximum time it might take to slew between two objects if you had to go the long way around, which in this case is 90 seconds. The maximum slew rate of four degrees per second is actually middle of the road for today's go to telescopes and faster than anticipated for these scopes. This could explain why the base weight was higher than expected.
Initial Setup
The initial setup for the SynScan controller remains unaffected regardless of whether the operator plans to utilize the tracking mode or the full go-to mode of operation. Operators are first required to enter their observing location, in degrees and minutes of longitude and latitude. Next, the correct time zone, defined by the GMT, must be entered. This includes a range of -5 to -8, -5 being the US east coast and -8 being the west coast. The local date and time is then required, as well as answering a simple "yes" or "no" question regarding Daylight Savings Time. For future use, the observing location and time zone will be retained, although the date and local time will require input at every start up.
Once this initial information is provided, the SynScan AZ controller gives you the option to begin alignment. If you are the type that abhors reading user's manuals, it would not be obvious that choosing not to begin alignment will put the telescope into the tracking mode. What is also not obvious without reading the user's guide is that the telescope optical tube needs to be oriented in an initial position, specifically level and facing north, for the tracking mode to operate. It should have been a simple matter for Orion to include those instructions in the SynScan software, and, hopefully, they will incorporate this recommendation in their next software release.
Tracking Operation
At higher magnifications, the tracking function is most valuable. Initial tests were conducted while Jupiter was still almost due south in the late fall of 2010. From its initial standpoint, leveled and facing north, the scope was manually aligned and centered on Jupiter, using 200x magnification. Though a demanding test, this is also a predictable common use for the function. Any residual drift should be easily noticeable at that magnification, and sure enough, there was a visible drift. The drift was noticeably different than that observed when using the telescope on the same target in the full go-to mode.
To test the drift, a 17mm Nagler eyepiece, producing a true field of 1.15 degrees, was inserted into the scope. This large field of view provided an enhanced opportunity in measuring the residual drift. Instead of conducting multiple tests lasting a few seconds, the tests were performed over a period of minutes. A bright star in the northeast and Jupiter to the south were used during the tests. Following the tests, an elapsed time of 5-10 minutes were recorded before the objects drifted from the center to the edge of the field.
Several factors must be taken into consideration when interpreting these results. First, no extraordinary measures were taken when leveling the base or locating true north while initializing the telescope. Second, any residual drift would be more evident a long way from the celestial pole, which is exactly where Jupiter was at the time. All in all, the tracking function was found to be adequate for its intended purpose.
Go To Alignment and Operation
It was presumed that the familiar two star alignment feature to be included, which it was. However, the user's manual revealed a new feature. The trend in go to telescopes over the past decade has been to simplify the process such that less and less knowledge is required of the operator. The Orion SkyQuest XT8g is no exception to this rule.
Orion offers a simplified alignment method called the brightest star method. In theory, this method frees the user from being required to know the names of any alignment stars. One simply looks around and aims the telescope at the brightest object in the night sky, other than the moon, and tells the SynScan controller what direction that object is located in (e.g. northeast, east, southeast, etc.) If the wrong direction is selected, the SynScan controller will advise that no bright object was found.
Assuming for a moment that your sense of direction is pretty good, the SynScan controller identifies the brightest star in that area and then offers a choice (by name) for the seconds alignment star. The user has the option to accept that choice or to scroll to another. Once a choice is accepted, the telescope slews to the near vicinity of that star. Anyone unable to identify any stars by name must take it on faith that the telescope slewed to the vicinity of the correct star. The alignment method was tested using different initial objects to confirm that it works. During one test, Jupiter was intentionally selected, and the SynScan controller correctly identified the object as Jupiter.
Two Star Alignment
For those who know their way around the sky will probably opt for the traditional two-star alignment. A majority of the tests conducted with the Orion XT8g telescope were centered on testing the two-star alignment feature. The telescope is provided with a 12.5mm reticle eyepiece for alignment purposes. From the tests, it was noted that this eyepiece was helpful, but not necessary, in order to get a good alignment. In attempt to get as much error as possible, a 35mm TeleVue Panoptic eyepiece was used during the first alignment. It was noted that the telescope would not reach focus with this eyepiece if fully seated in the focuser.
On the first series of tests, no special effort was made to level the telescope base. The level was probably off by at least three degrees. The first alignment stars were Cappella and Rigel -- or to be more precise, Cappella was chosen manually, while Rigel was listed as a suggestion.
The procedures of the first round of tests were repeated, although the telescope base was carefully leveled, using a spirit level. Cappella and Rigel were used as alignment stars. One key difference in pointing accuracy was noticeable; leveling the base greatly improved the pointing accuracy -- greater than using the reticle eyepiece. Nevertheless, the sample scope missed two out of seven test targets.
Doing it right...
If you were to stop into Skies Unlimited and purchase any altazimuth mounted go-to telescope, you would probably get a lecture on the proper technique for aligning the telescope. That lecture goes something like this:
"Start by facing south. Look over your left shoulder (east) and pick a bright object, then use that as your first alignment star. Now look over your right shoulder (west) and pick another bright object. Make sure that this object is at a different elevation, either higher or lower than the first object. Use this object as your second alignment star. Choosing two stars on opposite sides of the meridian that are widely separated in both altitude and azimuth will yield the best results in terms of go-to accuracy."
The long and the short of this advice comes down to accurately locating the meridian. Choosing stars on opposite sides of the meridian makes this a matter of mathematical interpolation. Choosing two stars on the same side of the meridian makes this a matter of extrapolation. The former method is usually more accurate, and in some cases it is MUCH more accurate.
Following a brief review using Starry Night Software, Cappella and Rigel were confirmed to be west of the meridian on the first night of testing. This does beg the question "why did the SynScan controller recommend Rigel as the second star?" Based on the time and date of the tests, Deneb would have been a better alternative. The logic behind this is hard to understand. Hopefully, with future software releases, Orion will correct this issue.
The Final Test
Armed with a good understanding of what went wrong revisited this test early in the spring of 2011. This time around, Arcturus was selected as the first alignment star, followed by Cappella as the second alignment star. These stars were on opposite sides of the meridian, and much more widely separated. For these tests, a 17mm TeleVue Nagler was used, rather than the reticle eyepiece. Result: the scope was capable of hitting Messier objects in every direction. It also easily located Saturn. All testing was performed using the 17mm TeleVue Nagler which has a slightly smaller field of view than the supplied 28mm Deep View eyepiece. Most objects were not perfectly centered in the eyepiece, but a few were. The only object the telescope failed to hit during the follow-up test was the moon. Considering the telescope successfully hit Saturn, which was approximately twenty degrees away, this failure was rather unusual. Under normal circumstances, a miss such as this is connected to an error in the date and time. As the telescope successfully hit Saturn, however, the date and time error is ruled out.
Summary
In comparison to other mass market Dobsonians, the Orion XT8g was noted as an absolute joy to use. This telescope's ability to automatically track its target makes all the difference in the world. When properly aligned, the go-to performance was more than adequate. Using the go-to function will either allow a novice observer to see an object he or she might have difficulty finding, or allow the more seasoned observer to see many more objects in a limited amount of time.
Following a brief review using Starry Night Software, Cappella and Rigel were confirmed to be west of the meridian on the first night of testing. This does beg the question "why did the SynScan controller recommend Rigel as the second star?" Based on the time and date of the tests, Deneb would have been a better alternative. The logic behind this is hard to understand. Hopefully, with future software releases, Orion will correct this issue.
The Final Test
Armed with a good understanding of what went wrong revisited this test early in the spring of 2011. This time around, Arcturus was selected as the first alignment star, followed by Cappella as the second alignment star. These stars were on opposite sides of the meridian, and much more widely separated. For these tests, a 17mm TeleVue Nagler was used, rather than the reticle eyepiece. Result: the scope was capable of hitting Messier objects in every direction. It also easily located Saturn. All testing was performed using the 17mm TeleVue Nagler which has a slightly smaller field of view than the supplied 28mm Deep View eyepiece. Most objects were not perfectly centered in the eyepiece, but a few were. The only object the telescope failed to hit during the follow-up test was the moon. Considering the telescope successfully hit Saturn, which was approximately twenty degrees away, this failure was rather unusual. Under normal circumstances, a miss such as this is connected to an error in the date and time. As the telescope successfully hit Saturn, however, the date and time error is ruled out.
Summary
In comparison to other mass market Dobsonians, the Orion XT8g was noted as an absolute joy to use. This telescope's ability to automatically track its target makes all the difference in the world. When properly aligned, the go-to performance was more than adequate. Using the go-to function will either allow a novice observer to see an object he or she might have difficulty finding, or allow the more seasoned observer to see many more objects in a limited amount of time.
In spite of the many features and capacities of the telescope, Orion should consider changing the star selection algorithm, in order to prevent the problems that surfaced during the first test run. This correction would help to ensure that this telescope delivers the high-quality go-to performance that it is capable of.
Thursday, May 19, 2011
Sky Highlight for May
A conjunction is a phenomenon in that two or more planets, when seen from a distance (usually somewhere on Earth), appear close to each other. Consider this the conjunction of the year -- the planets Mercury, Venus, Mars, and Jupiter, during the first 3 weeks of May, will be clustered together.
The conjunction will be observable in the eastern skies, 30 minutes prior to dawn. On the morning of May 11th, the planets were tightly clustered together in the constellation of Pisces. While the planets are generally observed through telescopes, the conjunction allows the astronomer to observe the planets with the unaided eye.
The conjunction will be observable in the eastern skies, 30 minutes prior to dawn. On the morning of May 11th, the planets were tightly clustered together in the constellation of Pisces. While the planets are generally observed through telescopes, the conjunction allows the astronomer to observe the planets with the unaided eye.
Following the conjunction, the movement of the planets will become readily noticeable day-by-day. By the end of the month, the planets will align along the ecliptic, or the imaginary line that the sun traces across the sky.
From the horizon up, the order of the planets will be as follows: Mercury, Venus, Mars, and Jupiter. A thin crescent moon will join the lineup on May 30th.
From the horizon up, the order of the planets will be as follows: Mercury, Venus, Mars, and Jupiter. A thin crescent moon will join the lineup on May 30th.
The origin of the word "planets" is the Greek translation to wandering stars. It was originally believed that the planets were stars, constantly moving across the sky relative to those that appeared stationary. The wandering motions of the planets vs. the stars will be easy to observe for the remainder of May into early June.
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