Choosing a New Telescope – GoTo or not GoTo

Guide to Meade Telescopes

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

Sunrise Photos from the Edge of Space shot by College Team

A sunrise from the edge of space. Credit: Project Soar

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A college-age team of space and photography enthusiasts have created a fully reusable capsule that can travel autonomously to the edge of space using high altitude balloons. To date, their capsule, named PURSUIT has had four flights, reaching altitudes ranging from 24,000 to 36,500 meters (80,000 to 120,000 feet.) “We wanted to fly capsules to the edge of space and capture the most difficult imagery that other teams didn’t even bother trying,” said Project Soar team leader David Gonzales II. “Our capsules shoot high resolution stills and shoot HD video of their incredible journeys.”

Last fall, the team captured the stunning image above of a sunrise from space from about 25,000 meters above the Earth. “To our knowledge, Sunrise Soar II captured the highest resolution images of sunrise ever taken from the edge of space by a high altitude balloon flight,” Gonzales told Universe Today.

A sunrise above most of Earth's atmosphere. Credit: Project Soar

In images taken from over 36,000 meters, absent are the reddish sunrise colors that we see on Earth because of the atmosphere.

Their PURSUIT capsule cost about $500 to put together initially, but their total cost per flight is only $40.

The crew consists of twelve different students and recent graduates from various colleges. Gonzales said he formed Project Soar and put together the team as a hobby. The team hopes to do several more flights soon.

The Sunrise Soar team filling the balloon. Credit: Proejct Soar

See more images and videos, and read detailed reports about the team’s adventures at their Project Soar website.

Success! The Sunrise Soar retrieves their capsule. Credit: Project Soar

International Space Station on the Moon?

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From our vantage point on Earth, it takes just a half second for the International Space Station to fly across the face of the Moon, so catching a transit is tricky. But award-winning French astrophotographer Theirry Legault captured an amazingly sharp and detailed transit image that makes the ISS look like it is sitting on the Moon’s surface! Legault took this image from Avranches (Normandy, France) a few hours before the eclipse, on December 20th at 21:34 UT. He used a Meade 10″ ACF on Takahashi EM400, with a Canon 5D mark II. The transit duration was just 0.55 seconds, as the ISS is traveling at 7.5km/s or 28,0000 km/h (17,500 mph). See below for a close-up crop of the image which shows the amount of detail visible of the space station.

Close-up of the ISS transiting the Moon. Credit: Theirry Legault. Used by permission.

Legault has also taken incredible images of the ISS and a docked space shuttle transiting the Sun, (at least twice), as well as the shuttle Atlantis and Hubble transiting old Sol.

See more of his images at his website, or click the images for larger versions. Legault told us he’ll be traveling for a good view of the solar eclipse on January 4, so we look forward to his images of that event.

Aesthetics of Astronomy

This Hubble image reveals the gigantic Pinwheel Galaxy (M101), one of the best known examples of "grand design spirals," and its supergiant star-forming regions in unprecedented detail. Astronomers have searched galaxies like this in a hunt for the progenitors of Type Ia supernovae, but their search has turned up mostly empty-handed. Credit: NASA/ESA

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When I tell people I majored in astronomy, the general reaction is one of shock and awe. Although people don’t realize just how much physics it is (which scares them even more when they found out), they’re still impressed that anyone would choose to major in a physical science. Quite often, I’m asked the question, “Why did you choose that major?”

Only somewhat jokingly, I reply, “Because it’s pretty.” For what reasons would we explore something if we did not find some sort of beauty in it? This answer also tends to steer potential follow up questions to topics of images they’ve seen and away from topics from half-heard stories about black holes from sci-fi movies.

The topic of aesthetics in astronomy is one I’ve used here for my own devices, but a new study explores how we view astronomical images and what sorts of information people, both expert and amateur, take from them.

The study was conducted by a group formed in 2008 known as The Aesthetics and Astronomy Group. It is comprised of astrophysicists, astronomy image development professionals, educators, and specialists in the aesthetic and cognitive perception of images. The group asked to questions to guide their study:

1. How much do variations in presentation of color, explanatory text, and illustrative scales affect comprehension of, aesthetic attractiveness, and time spent looking at deep space imagery?

2. How do novices differ from experts in terms of how they look at astronomical images?

Data to answer this question was taken from two groups; The first was an online survey taken by volunteers from solicitations on various astronomy websites and included 8866 respondents. The second group was comprised of four focus groups held at the Harvard-Smithsonian Center for Astrophysics.

To analyze how viewers viewed color, the web study contained two pictures of the elliptical galaxy NGC 4696. The images were identical except for the colors chosen to represent different temperatures. In one image, red was chosen to represent hot regions and blue for cold regions. In the other version, the color scheme was reversed. A slight majority (53.3% to 46.7%) responded saying they preferred the version in which blue was assigned to be the hotter color. When asked which image they thought was the “hotter” image, 71.5% responded that the red image was hotter. Since astronomical images are often assigned with blue as the hotter color (since hotter objects emit shorter frequency light which is towards the blue end of the visible spectrum), this suggests that the public’s perception of such images is likely reversed.

A second image for the web group divided the participants into 4 groups in which an image of a supernova remnant was shown with or without foreground stars and with or without a descriptive caption. When asked to rate the attractiveness, participants rated the one with text slightly higher (7.96 to 7.60 on a 10 point scale). Not surprisingly, those that viewed the versions of the image with captions were more likely to be able to correctly identify the object in the image. Additionally, the version of the image with stars was also more often identified correctly, even without captions, suggesting that the appearance of stars provides important context. Another question for this image also asked the size in comparison to the Earth, Solar System, and Galaxy. Although the caption gave the scale of the SNR in lightyears, the portion that viewed the caption did not fare better when asked to identify the size revealing such information is beyond the limit of usefulness.

The next portion showed an image of the Whirlpool galaxy, M51 and contained either, no text, a standard blurb, a narrative blurb, or a sectionized caption with questions as headers. Taking into consideration the time spent reading the captions, the team found that those with text spent more time viewing the image suggesting that accompanying text encourages viewers to take a second look at the image itself. The version with a narrative caption prompted the most extra time.

Another set of images explored the use of scales by superimposing circles representing the Earth, a circle of 300 miles, both, or neither onto an image of spicules on the Sun’s surface, with or without text. Predictably, those with scales and text were viewed longer and the image with both scales was viewed the longest and had the best responses on a true/false quiz over the information given by the image.

When comparing self-identified experts to novices, the study found that both viewed uncaptioned images for similar lengths of time, but for images with text, novices spent an additional 15 seconds reviewing the image when compared to experts. Differences between styles of presenting text (short blurb, narrative, or question headed), novices preferred the ones in which topics were introduced with questions, whereas experts rated all similarly which suggested they don’t care how the information is given, so long as it’s present.

The focus groups were given similar images, but were prompted for free responses in discussions.

[T]he non-professionals wanted to know what the colors represented, how the images were made, whether the images were composites from different satellites, and what various areas of the images were. They wanted to know if M101 could be seen with a home telescope, binoculars, or the naked eye.

Additionally, they were also interested in historical context and insights from what professional astronomers found interesting about the images.

Professionals, on the other hand, responded with a general pattern of “I want to know who made this image and what it was that they were trying to convey. I want to judge whether this image is doing a good job of telling me what it is they

wanted me to get out of this.” Eventually, they discussed the aesthetic nature of the images which reveals that “novices … work from aesthetics to science, and for astrophysicists … work from science to aesthetics.”

Overall, the study found an eager public audience that was eager to learn to view the images as not just pretty pictures, but scientific data. It suggested that a conversational tone that worked up to technical language worked best. These findings can be used to improve communication of scientific objectives in museums, astrophotography sections of observatories, and even in presentation of astronomical images and personal conversation.

Stunning Look at ISS and Docked Disovery — From the Ground!

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This has to be one of the clearest close-up shots of the International Space Station ever taken from the ground! Plus it has the added bonus of having space shuttle Discovery docked to the station. Ted Judah, who lives in northern California captured this image — one of 150 he took during the an ISS pass over his observatory during the recent STS-131 mission. Here’s Ted’s description:

The ISS came into the morning light over the Pacific Ocean just off the coast of northern California and was tracking north-east as it passed directly over my sea-level observatory. I was lucky there was no fog. I have a Canon 30D SLR and Celestron 11″ Schmidt-Cassagrain on an equatorial mount. I track manually and use my precisely-aligned finderscope to aim – when the ISS is in the crosshairs I shoot like crazy. Of the 150 shots I took, less than half have the ISS in frame.

Ted told me he was “stoked” to get such a clear image. Who wouldn’t be?? Nice work, Ted!

Ted is not new to trying to capture the ISS. He won one of “Phil’s Picks” (Bad Astronomer Phil Plait) in Celestron’s “Capture the Universe” contest with another image of the ISS.

Also, Ted has contributed a couple of podcasts to 365 Days of Astronomy, and one of my all-time favorite podcasts is Ted’s description of how he and his family built an observatory out on his father-in-law’s farm.

Here’s another shot Ted took during the same pass:

The ISS and shuttle Discovery during the STS-131 mission. Credit: Ted Judah

Thanks Ted, for sharing your wonderful images!

Wow! Astronauts on EVA, As Seen From Earth

Ralf Vandebergh’s detail of an image he took on March 21, 2009 showing astronauts working outside the ISS. Credit: Ralf Vandebergh

Remember when it was a big deal when amateur astronomers starting imaging the International Space Station as seen from Earth, showing individual modules and other parts of the space station? One of the most proficient astrophotographers in that department has now just upped the game: Ralf Vandebergh has captured images of astronauts working outside the ISS during an EVA. Vandebergh, who lives in The Netherlands, used his 10-inch Newtonian backyard telescope to capture an image of STS-119 astronauts Joe Acaba and Steve Swanson working outside the ISS to install equipment on one of the trusses during the second EVA of the mission on March 21, 2009. Vandebergh told me he has been trying to image astronauts working outside the ISS since 2007, but hasn’t been successful until now. “In all opportunities I had until now, the astronauts were not on a visible part of the station,” he said “or they were in shadow or the pass or the seeing was simply not favourable.”

Below, enjoy the video Vandebergh created about his extreme zoom-in handiwork, and his explanation of how he was able to take the images.

Nice job Ralf! Check out his website of other telescopic spacecraft image here.

“It was great luck they were working on the Earth-facing side of the port 3 truss on this spacewalk,” Vandebergh said. “Why? This truss is a reasonable open structure, which means it appears a little bit transparent as seen from the Earth with the black space as a background. This makes this particular truss (and the Starboard 3 truss on the other side) look considerably darker then the other trusses in the vicinity.
When a high reflective white suited spacewalker works in front of this truss, there is a very good
chance you receive light from it on your CCD. By following very precisely the live station camera’s–
and helmet cam recordings on NASA TV, I knew exactly were to expect them on the image.”