Posted on by VirtualAstro

Choosing a New Telescope – GoTo or not GoTo

Guide to Meade Telescopes
MeadeETX125PE

I am often asked by people “I’m a beginner, so what telescope should I buy?” Or more often, what GoTo telescope would I recommend for someone starting out in astronomy?

When venturing out and buying your first telescope, there are a number of factors to consider, but because of glossy advertising and our current digital age, the first telescope that people think of is a GoTo.

Do you really need a GoTo or would a manual telescope suffice? In order to make a good decision on what telescope to buy, you need to decide on what you want to use the telescope for — observing, photography, or both and does it need to be portable or not? This will help you make the best decision for the mount of your telescope.

GoTo telescopes are usually advertised as being fully automatic and once they have set themselves up, or are set up by the user, they can access and track and many thousands of stars or objects with just a simple touch of a button. These features have made GoTo scopes are very desirable with many astrophotographers.

Manual telescopes are not automatic or driven by motors as GoTo scopes are. They are predominantly used for observing (using your eyes instead of a camera) and the scope is moved by hand or by levers by the user to find different objects in the eyepiece. Manual telescopes usually have a finder scope, red dot finder or laser finder to aid in finding objects in the eyepiece. They are unable to track objects, which can make them unsuitable for photography.

GoTo Vs Manual
Compared to GoTo telescopes, manual telescopes are much more economical as you are basically buying a very simple mount and an optical tube assembly (the telescope tube, or OTA). With GoTo you are adding electronics and control mechanisms to drive the scope, which can add heavily to the cost. A small GoTo telescope could cost the same as a lot larger manual Dobsonian telescope.

Good GoTo telescopes make astrophotography very accessible and enjoyable, especially with the addition of cameras and other kits. As opposed to manual scopes, GoTos can be used for long exposure astrophotography. Be aware though, that much astrophotography is done with very expensive imaging equipment, but good results can be achieved with web cams and DSLR cameras.

Manual telescopes are brilliant at helping you discover and learn the sky as you have to actually hunt or star hop for different objects. I once met a person who had been using a GoTo telescope heavily for a year, and at a star party I asked her to show some kids where a well known star was with my laser pointer, she didn’t know because she was used to her GoTo scope taking her to objects.

So which one should you buy?
I would recommend for pure visual observing a manual telescope such as a large Dobsonian or Newtonian telescope. The human eye needs as much light to enter it as possible to see things in the dark, so a big aperture or mirror means greater light gathering and more light entering your eye, so you can see more. What you saved by not having GoTo, you can spend on increasing the size of your telescope.

If you want to add photography or imaging capabilities then I would definitely recommend a good quality GoTo scope or mount. You will get a smaller aperture compared to the manual scope for the same money, but the scope will track for astro-imaging and can also be used for visual observing. Be prepared to spend a lot more money, though.

Consider how you want to use your telescope and the size of your budget. Avoid buying low end, cheap, budget, or what is known as “department store” telescopes to avoid disappointment. Save up a little longer and get a good telescope. Visit your local astronomy store or telescope distributor and before you buy ask an astronomer, they will be glad to help.

I hope you enjoy your new telescope for many years to come 🙂

Dobsonian Telescope

Posted on by VirtualAstro

How To See NanoSail-D From Your Own Backyard

Artist concept of Nanosail-D in Earth orbit. Credit: NASA

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The night sky has many wonderful objects to look at on a clear evening, including many man-made satellites, and the always impressive International Space Station (ISS). Now there’s a new addition to these artificial delights: the first ever solar sail to orbit the Earth, NASA’s Nanaosail-D Satellite. Want to know how you can see it?

The 10m x 10m reflective sail is designed to act like a brake and gradually create drag in the upper atmosphere, slowly pulling a satellite down and de-orbiting it at the end of its working life. Nanosail-D is testing the potential of this technology to reduce space junk and debris.

NanoSail D. Image credit NASA

The satellite has a huge reflective sail and could potentially be many times brighter than the planet Venus when it catches a glint from the Sun. Unlike the International Space Station (ISS) and other satellites, the sail will not be visible when it is directly above us as we will be looking at it edge on, It will be more visible when closer to the horizon.

The Nanosail-D satellite will be visible from now and for the next few months. To see it you will need to know exactly when it will be visible from your location. To do this, go to heavens-above.com or spaceweather.com where star charts with times and pass details will be displayed after you enter your observing site.

Once you know the time and location in the sky of the pass of the satellite, make sure you are able to get a good view of the horizon, or part of the sky where the satellite due to appear. Give yourself plenty of time, go outside and get ready. I always set a 30 second reminder on my watch or cell phone, so I don’t have to fumble around or guess the time.

Unlike the ISS and most other satellites, Nanosail-D passes may only last a few, or a few tens of seconds, so make sure you are looking in the right place at the right time. You will see an amazingly bright star-like object rise up, get brighter and then suddenly disappear. When it “disappears” it is still passing over, it’s just no longer at the right angle or is no longer being illuminated by the sun. NanoSail-D has few reflective surfaces compared to many on the ISS.

To enjoy the Nanosail-D passes:

• Make sure you know the right place in the sky and the time of the pass, by checking on the web.
• Make sure you will be able to get a clear view of it from your viewing location.
• Set an alarm or get ready for the pass as it only lasts a few seconds.
• NASA expects NanoSail-D to stay in orbit until April or May 2011.
• If you are an astrophotographer, don’t forget, NASA and SpaceWeather.com are having an imaging contest of NanoSail-D. Find out more here.
• Most of all, get your friends and family outside with you to watch Nanosail-D and enjoy!

Posted on by Tammy Plotner

Observing Alert: Z Canis Major In Outburst

Z Canis Major - Credit: Palomar Observatory, courtesy of Caltech

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Heads up, weekend warriors! With very little Moon to contend with, it would be a great time to observe the bright outburst of the pre-main sequence variable star, Z Canis Major. It has gained more than two magnitudes and is well within binocular and small telescope range.

From the AAVSO Special Notice compiled by Elizabeth O. Waagen: “John Bortle, Stormville, NY, reports that the pre-main sequence binary variable Z CMa is in outburst, according to his observation of 2011 February 4.0 UT at visual magnitude 8.5. Observations in the AAVSO International Database confirm this outburst, which may have begun as long ago as April 2010, when it began brightening slightly from visual magnitude 10.7. When Z CMa emerged from its seasonal gap in November 2010, it was already 9th magnitude.

Locator Chart Courtesy of AAVSO

The current outburst is as bright as the one that occurred in 2008, the brightest in the star’s known history. Z CMa is a very interesting object, a binary composed of a Herbig Be star and an FU Ori star. The Herbig star is embedded in nebulosity. The system is an x-ray source and has an x-ray jet. According to Stelzer et al. (2009, Astronomy & Astrophysics v.499, p.529, and astro-ph arXiv:0903.4060), the FU Ori star is the source of both the optical outbursts and the x-ray emission. Observations of Z CMa (RA 07:03:43.16 Dec -11:33:06.2) are strongly encouraged, both during the current outburst and throughout the observing season. With its range of visual magnitude ~8.0 – 10.5, it is an excellent visual observing target.”

Our thanks to John Bortle and the American Association of Variable Star Observers (AAVSO) for drawing our attention to the current outburst of this interesting system!

Posted on by Nancy Atkinson

Travel Destination: World’s First Dark Sky Island

An aerial view of Sark.

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Looking for a great vacation spot with those all-important dark skies for astronomical observing? A small island in the English Channel off the French coast of Normandy might be just what you are looking for. The Channel Island of Sark has been officially recognized for the quality of its night sky by the International Dark-sky Association (IDA), who have designated it as the world’s first dark sky island, the latest in a select group of dark sky places around the world.

An aerial view of Sark.

What makes the Sark skies so dark? The island has no public street lighting, there are no paved roads and cars, so effectively, there is no light pollution in the skies. Those who have been there say the night sky is very dark, with the Milky Way stretching from horizon to horizon, meteors streaking overhead, and countless stars on display.

The people who live there have made dark skies one of their priorities. Through a long process of community consultation, a comprehensive lighting management plan was created by Jim Patterson of the Institute of Lighting Engineers, and many local residents and businesses have altered their lighting to make them more dark sky friendly, ensuring that as little light as possible spills upwards where it can drown out starlight.

Roger Davies, president of the Royal Astronomical Society, said, “This is a great achievement for Sark. People around the world are become increasingly fascinated by astronomy as we discover more about our universe, and the creation of the world’s first dark sky island in the British Isles can only help to increase that appetite. I hope this leads to many more people experiencing the wonders of a truly dark sky.”

For more information on Sark, see the island’s website.

For more information on the International Dark-sky association: http://www.darksky.org/

Source: Royal Observatory Greenwich

Posted on by Nancy Atkinson

See NanoSail-D in Orbit, Win a Prize!

Looking for the orbiting NanoSail-D just got more exciting! NASA and Spaceweather.com have teamed up to offer prizes for the best amateur astronomy image of the now-orbiting and unfurled NanoSail-D solar sail. NanoSail-D unfurled the first 100-square-foot solar sail in low-Earth orbit on Jan. 20.

To encourage observations of NanoSail-D, Spaceweather.com is offering prizes for the best images of this historic, pioneering spacecraft in the amounts of $500 (grand prize), $300 (first prize) and $100
(second prize).

The contest is open to all types of images, including, but not limited to, telescopic captures of the sail to simple wide-field camera shots of solar sail flares. If NanoSail-D is in the field of view, the image is eligible for judging.

The solar sail is about the size of a large tent. It will be observable for approximately 70 to 120 days before it enters the atmosphere and disintegrates. The contest continues until NanoSail-D re-enters Earth’s atmosphere.

NanoSail-D will be a target of interest to both novice and veteran sky watchers. Experienced astrophotographers will want to take the first-ever telescopic pictures of a solar sail unfurled in space.
Backyard stargazers, meanwhile, will marvel at the solar sail flares — brief but intense flashes of light caused by sunlight glinting harmlessly from the surface of the sail.

NanoSail-D could be five to 10 times as bright as the planet Venus, especially later in the mission when the sail descends to lower orbits. The NanoSail-D satellite was jointly designed and built by NASA engineers from the agency’s Marshall Space Flight Center in Huntsville, Ala., and NASA’s Ames Research Center in Moffett Field, Calif.

To learn more about the NanoSail-D imaging challenge and contest rules, satellite tracking predictions and sighting times, visit this page about NanoSail-D. (not much info there yet as I write this….)

or see the NanoSail-D website for more info about the solar sail mission.

Posted on by Nancy Atkinson

Win iPhone App for Observing: TeleCalc

Screenshot from 'TeleCalc'

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There’s a new observing app for the iPhone, iPod and iPad, called TeleCalc. Enter in two data points about your telescope (aperture and focal ratio) and two about the eyepiece (focal length and diameter) the program calculates angular field of view, best eyepiece magnification, resolution (Dawes, Rayleight), exit pupil, limiting stellar magnitude and light gathering power.

TeleCalc is available in eight languages: English, Spanish, French, Italian, German, Portuguese, Russian and Japanese. Search “TeleCalc” in iTunes to download it or find it on the iTunes store.

Thanks to developer Fabio Rendelucci who has given Universe Today 3 free TeleCalc apps to give away.

The first 3 people to answer the following question will be sent a code for a free TeleCalc app:

To find the magnifying power of any telescope, divide the focal length of the telescope by the focal length of the what other telescope piece?

Submit your answers in the “Comments”

Also, if you’re looking for more, take a look at all the apps that NASA has available for both iPhone and Android.

Posted on by Tammy Plotner

2011 Quadrantid Meteor Shower… Tonight’s the Night!

"Fireball Breakup" by John Chumack

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In just a few hours the peak of the first meteor shower of 2011 will begin – the Quadrantids. Where did these mysterious meteors begin their life and how can you observe one yourself? Then step inside…

Beginning each New Year and lasting for nearly a week, the Quadrantid Meteor Shower sparkles across the night sky for nearly all viewers around the world. Its radiant belongs to an extinct constellation once known as Quadran Muralis, but any meteors will seem to come from the general direction of bright Arcturus and Bootes. This is a very narrow stream, which may have once belonged to a portion of the Aquarids, but recent scientific data points to a what may have been a cosmic collision. According the most recent data, the Quandrantid meteors may have been formed about five centuries ago when a near-Earth asteroid named 2003 EH1 and a comet smashed into one another. Historic records from ancient China put comet C/1490 Y1 in the path of probability.

As Jupiter‘s gravity continues to perturb the stream, another 400 years may mean this shower will become as extinct as the constellation for which it was once known, but we aren’t out of the running just yet. “Peaking in the wee morning hours of Tuesday, Jan. 4, the Quads have a maximum rate of about 100 per hour (varies between 60 and 200),” says Bill Cooke of NASA’s Meteoroid Environment Office. “What makes this year so special is that the Moon is New on the night of the peak, so there will be no interference from moonlight.”

As exciting as it may seem, there are a few problems associated with observing the Quadrantid meteor shower. The first is the weather, because this northern hemisphere show occurs during a notoriously cold season making observations uncomfortable at best. The second is the brevity of the activity itself. Because Earth intersects the debris orbit of 2003 EH1 at a perpendicular angle, we zip right through the trail. That’s why the shower activity is so fast and slightly unpredictable. A third consideration is the high probability of cloud cover – but take heart… NASA has you covered!

“Got clouds? No problem.” says SpaceWeather. “You can stay inside and listen to the Quadrantids. Tune into SpaceWeather Radio for a live audio stream from the Air Force Space Surveillance Radar. When a Quadrantid passes over the facility, you will hear a “ping” caused by the radar’s powerful transmitter echoing from the meteor’s ion trail. During the shower’s peak, the soundtrack is guaranteed to entertain.

So where and when to look? “You can start watching after 2:30am in the North to North East look between the handle of the Big Dipper -Ursa Major and the Constellation of Bootes or the Kite shaped constellation, this is the radiant location as the Meteors will appear to radiate from this general area.” says professional astrophotographer, John Chumack. “Or after 2:30am simply look between the North Star and bright star Arcturus in the East. The Quadrantid Meteors will appear to be coming from this general area of the sky. There is no moon present during this year’s shower, so you can watch all night if you like without moonlight interfering, but the best time will be after 2:30am. As the night goes on the Big Dipper, Bootes and Arcturus climb higher into the sky, so keep watching because the number of meteors usually picks up after 2:30am and gets better through 6:00am. as Earth rotates into the stream. Meteors can appear anywhere in the sky, so look in all directions of the sky as the Quadrantid radiant reaches straight over head. The Quadrantid Meteors are rather fast movers. They enter the atmosphere at about 90,000 to 120,000mph, and can have some impressive long trails.”

Will the Quadrantid Meteor Shower live up to its expectations? No one knows for sure… But we’ll be watching!

Many thanks to John Chumack of Galactic Images for his inspiring photo and to NASA for the locator chart. We thank you so much!

Posted on by Tammy Plotner

Total Lunar Eclipse Information – December 21, 2010

Are you ready? As promised, here comes more detailed information on the 2010 total lunar eclipse. Step inside and find out where and when to watch!

The eclipse begins for eastern North America on Tuesday morning, Dec. 21st, at 1:33 am EST and occurs on Monday night, Dec. 20th, at 10:33 pm PST for western North America. At that time, Earth’s shadow will appear as a dark-red crescent at the edge of the lunar disk. It takes about an hour for the Earth’s shadow to fully encompass the visible side of the Moon. Totality commences at 02:41 am EST (11:41 pm PST) and lasts for 72 minutes. Western Europe and the northwestern portion of Africa will also be treated to a portion of the eclipse at moonset. The point of deepest shadow will occur at 08:17 UT and totality ends 36 minutes later at 08:53 UT. At that time, a silver sliver will once again appear along the lunar limb, where for one hour and eight minutes it will continue until the Moon passes out of the umbral shadow at 10:01 UT. From there it will pass into the penumbral shadow for an additional hour and four minutes until the show ends at 11:05 UT.

Where will the Moon appear? Of course it will be along the ecliptic plane and in very good company – riding high above Orion. Be sure to look for a triple red treat as the show forms a triangle with blushing Betelgeuse and ruddy Aldebaran. As the Moon darkens, be sure to look for wonderful unaided eye deep space objects you can’t see during a full Moon – like the Plieades (M45) and the Great Orion Nebula (M42). What a Christmas treat!

Photographing or videotaping a total lunar eclipse is quite easy, but remember if you live in a cold climate that there are a few very important rules to follow. Number one is to be sure to protect your hands. It’s very easy to get involved with the equipment and ignore what seems like a slight discomfort. You don’t want to experience freezing your fingers to a metal surface or risking frostbite! The second rule is to remember that cold batteries drain very, very quickly. You can easily avoid frustration by simply keeping spares somewhere handy next to your skin. Of course, getting to them might be a ticklish situation! The last rule to remember is simply to dress for success. Multiple loose layers of clothing, hat, gloves and proper footgear are a must where the winter season means bitter cold temperatures.

Now all that’s left is just to let the hours count down… and enjoy!

Fun Facts from NASA: This lunar eclipse falls on the date of the northern winter solstice. How rare is that? Total lunar eclipses in northern winter are fairly common. There have been three of them in the past ten years alone. A lunar eclipse smack-dab on the date of the solstice, however, is unusual. Geoff Chester of the US Naval Observatory inspected a list of eclipses going back 2000 years. “Since Year 1, I can only find one previous instance of an eclipse matching the same calendar date as the solstice, and that is 1638 DEC 21,” says Chester. “Fortunately we won’t have to wait 372 years for the next one…that will be on 2094 DEC 21.”

Posted on by Tammy Plotner

Total Lunar Eclipse – December 21, 2010

Both lunar and solar eclipses can only occur when the Earth, Sun and Moon are directly aligned… and that alignment is about to happen just four days before Christmas! While the winter treat of totality will lend itself to North America, many other parts of the world will be able to enjoy a partial eclipse as well. Just remember your time zones and I’ll post specific times and locations just a little closer to the date. Right now, let’s learn more!

What is a partial eclipse or totality? When the Earth’s shadow engulfs the Moon, it is a lunar eclipse which occurs in two phases. The outer shadow cone is called the penumbra and the dark, inner shadow is called the umbra. A round body, such as a planet, casts a shadow “cone” through space. When it’s at Earth, the cone is widest at 13,000 kilometers in diameter, yet by the time it reaches the Moon it has narrowed to only 9,200 kilometers. Considering the distance to the Moon is 384,401 kilometers, that’s hitting a very narrow corridor in astronomical terms!

As a rule of thumb, remember that the Moon moves about its own diameter each hour, so the very beginning of a penumbral eclipse will be difficult to notice. Slowly and steadily, the coloration will begin to change and even inexperienced eclipse watchers will notice that something is different. The Moon will never completely disappear as it passes through the Earth’s umbral shadow cone, either. Thanks to our atmosphere bending the sunlight around us, it scatters the light and refracts the signature red and copper coloration we associate with lunar eclipse. Why? Just the small particles in our air – dust and clouds – the shorter wavelengths of light from the Sun are more likely to be scattered (in this case, red) and that’s what we see. Exactly the same reason sunset and sunrise appears to be red! If you’d like to dedicate a portion of your mind to science, then try judging the eclipse coloration on the Danjon scale. It was was devised by Andre Danjon for rating the overall darkness of lunar eclipses:

L=0: Very dark eclipse. Moon almost invisible, especially at mid-totality.
L=1: Dark Eclipse, gray or brownish in coloration. Details distinguishable only with difficulty.
L=2: Deep red or rust-colored eclipse. Very dark central shadow, while outer edge of umbra is relatively bright
L=3: Brick-red eclipse. Umbral shadow usually has a bright or yellow rim.
L=4: Very bright copper-red or orange eclipse. Umbral shadow is bluish and has a very bright rim.

Now we know what to plan for! Time to get your winter gear ready. Photographing or video taping an eclipse is easy – but remember if you live where it is very cold that your batteries will expire fast – so keep an extra set in a warm place next to your body.

Be sure to check back for specific times and locations here at UT on December 20th… and tell your family and friends about the very special Christmas present that’s coming your way!

Eclipse Images Courtesy of Doug Murray (top), Tom Ruen (bottom) and NASA (center illustration). We thank you!

Posted on by Nancy Atkinson

How Are You Celebrating the Year of the Solar System?

There are a lot of solar system space missions coming up, plus – as always – a plethora of astronomical events taking place, so NASA has decided to declare the “Year of the Solar System” (YSS). But this year is so big, it won’t fit into an Earth year — however, a Martian year just about covers it, so from now until August, 2012 we’re celebrating.

“During YSS, we’ll see triple the usual number of launches, flybys and orbital insertions,” said Jim Green, the director of Planetary Science at NASA headquarters. “There hasn’t been anything quite like it in the history of the Space Age. History will remember the period Oct. 2010 through Aug. 2012 as a golden age of planetary exploration.”

Below you’ll see a list of mission activities that will take place, but also, the YSS organizers will have special events – both online and at various venues – to help us all celebrate.

One project near and dear to my heart is the 365 Days of Astronomy podcast, which will be continuing at least through 2011. Universe Today readers, you’d help me out A LOT (I’m the 365 Days project manager) by signing up to do a podcast. Podcasting is an easy and wonderful way to share your knowledge, experiences and love of astronomy or space. We give you lots of info about what you need to do to created a podcast. Check out the website, the calendar for available dates in 2011, and you can contact me directly to sign up for a date!

For other things associated with the YSS, there are also activities and materials available for classrooms and teachers, afterschool programs, astronomy clubs and more.

Right now, during December and January, the activities focus on investigations of our planetary family tree. Conduct the Explore the Celestial Neighborhood … in Your Neighborhood! activity and others fun projects that examine what a planet is and how we investigate planets.

There is also information on how to observe the total lunar eclipse on December 21, or activities to simply note the change in lunar phases over the course of a month.

You can also submit photographs, artwork, music, or words of your YSS experiences at the Share Your Stories page.

This artist's illustration shows how the Sun would have looked from Carl Sagan Memorial Station at a specific time each month on Mars over the course of a Martian year. (Credit: Dennis Mammana)

As far as the solar system missions going on we’ve already enjoyed the flyby of Comet Hartley 2 by the Deep impact/EPOXI spacecraft, and the NASA O/OREOS (“Organism/ORganic Exposure to Orbital Stresses,”) spacecraft was launched in November 2010, to study “the durability of life in space.” It is a nanosatellite (a cubesat), only 5.5 kilograms in mass, and we’ll certainly be hearing more about that spacecraft soon.

NASA NanoSail-D was also launched by the same rocket, and it has been ejected from the spacecraft but hasn’t yet unfurled its sails. We’ll post something as soon as any news on that emerges.
Here are more upcoming mission highlights as part of the YSS:

Stardust NExT encounters comet Tempel on February 14.

MESSENGER enters an orbit around the planet Mercury on March 18.

Dawn begins its approach to the asteroid Vesta in May, for a mission between 2011 and 2012. It will also visit the dwarf planet Ceres in 2015.

The Juno spacecraft will launch to Jupiter in August 2011. It will study the planet’s composition, gravity field, magnetic field, and polar magnetosphere.

GRAIL, or the NASA Gravity Recovery and Interior Laboratory (GRAIL) spacecraft will launch for a mapping mission to the Moon in September 2011.

Curiosity, or the Mars Science Lab will launch in November 2011. This is a big, car-sized rover that will look for potential habitable places, and more, on Mars. Curiosity is slated to land in August, 2012.