Starry Night® Times

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Welcome again to our monthly newsletter with features on exciting celestial events, product reviews, tips & tricks, and a monthly sky calendar. We hope you enjoy it!


Orion EON 120mm ED Apochromatic Refractor

Five years ago, Orion® released their first ED refractor—an 80mm f/7.5—at an unprecedented low price. I was one of the earliest purchasers of this scope and continue to be amazed at the quality of its images.

The 80mm was soon followed by a 100mm f/9, which I also ordered the first day it appeared on Orion®’s web site. There followed a third ED refractor—a 120mm f/7.5—which I decided to skip because I feared its short focal ratio would produce too much chromatic aberration.

Recently Orion® has announced a new series of ED refractors with vastly improved mechanical construction. Not that I had any complaints about my 80ED and 100ED, but there was room for improvement.

I was recently loaned one of Orion®’s new 120mm f/7.5 EON apochromats for testing. The first big surprise was that it came packed in a very solid fitted foam lined carrying case with cutouts for the optical tube assembly itself, several eyepieces, and a 2-inch diagonal. The tube assembly is now finished in a rich glossy black with a sliding dew shield and fitted metal dew cap at one end and, at the other, a heavy duty rotatable dual-speed Crayford focuser.

In between is a set of felt lined tube rings attached to a standard Vixen/Synta dovetail and a standard dovetail finder shoe—for once located properly on the tube itself, not back on the focuser where it interferes with the diagonal and eyepiece. The entire assembly is clearly heavy-duty and business-like but also, thanks to its precision machining and glossy finish, downright beautiful! The huge objective has impeccable coatings, making it almost invisible when you look in the dew shield.

For testing purposes, I mounted the scope on my trusty Vixen Super Polaris mount, a very handsome and solid combination. Like the other scopes in this series, the EON 120 does not come with finder, diagonal, or eyepieces, so I attached an Orion® 6x30 finder, a 2-inch William Optic dielectric diagonal, and my usual assortment of eyepieces.

Planetary parade

June offered a fine variety of planets to test this scope’s mettle. As evening fell, Saturn was a lovely sight in the west; I was able to comfortably use 225x. Because of the current narrowness of the rings, Cassini’s Division was only suspected, but the detail of ring and planet and their shadows was beautifully clear. I stayed up late to observe Jupiter at its highest, and was treated to a fine view of the giant planet. The North Equatorial Belt was an intense chocolate brown, while the South Equatorial Belt was wide, orange-colored, and filled with intricate detail.

By the time the Great Red Spot rolled around into view, the telescope’s objective had begun to dew up, reducing the contrast of the image. I could see the lighter Red Spot Hollow clearly, but could not quite make out the Red Spot itself. A few nights later with my 11-inch Schmidt-Cassegrain I was able to see little more detail than with the 120mm EON; Jupiter is just too tough a target when it is so low in the sky for an observer located at 45° N latitude!

A moon a few days short of full provided a different sort of challenge for the EON. The huge difference in contrast between the sunlit lunar highlands and the deep shadows of craters is an acid test for a refractor. Any shortfall in color correction will be brutally revealed by color fringing due to chromatic aberration. I had doubts whether a 120mm f/7.5 ED doublet could meet such a challenge, but the EON put my doubts to rest. The moon’s surface was cleanly rendered in tones of white, black, and grey, with not a hint of color fringing around the brightest highlights or within the deepest shadows: a stunningly good performance!

Double stars

The present popularity of refractors has led amateur astronomers to rediscover the beauties of double and multiple stars, a popular target for an earlier generation of amateur astronomers. Although beautiful in any telescope, double stars are a special treat in a refractor thanks to the telescope’s clean uncluttered images. I turned first to Algieba (Gamma Leonis), a beautiful golden pair at 150x. Next was my all-time favorite multiple star, Epsilon Lyrae, the Double Double.

At first glance a wide pair, closer examination reveals that each of the two stars is in itself a really close binary. At 225x all four stars were cleanly visible. The biggest challenge of the night was Porrima (Gamma Virginis). Most of the time this is quite an easy pair, but for the last few years the two component stars have been extremely close together and inseparable in even the largest telescopes.

At 225x, I was just able to see this star as a “peanut” shape, its two components merging along their central zone. The separation of the two components is only 1.1 arcseconds at present, so detecting any separation was a triumph for this scope.

Deep sky wonders

There is a popular myth that refractors only excel at lunar and planetary observing, and that deep sky observing is the property of large Newtonians—not so! One of my most memorable deep sky observing sessions years ago was with a Celestron 150mm f/8 achromatic refractor, whose contrast and light throughput yielded views I’d expect only from a larger telescope. So I was looking forward to trying out the EON 120mm on some favorite deep sky targets.

First up was my old friend M57, the Ring Nebula in Lyra. At 56x it was a perfect smoke ring. Next was one of my favorite galaxies, M104 in Virgo, the Sombrero. At 56x it showed a clear hint of its central dark lane, quite remarkable in such a small aperture. M13, the great globular cluster in Hercules, was nicely resolved into stars at 82x. The Dumbbell Nebula in Vulpecula was easy to see without a filter, but really jumped out from the background with an OIII filter in place. The Veil Nebula was invisible without the filter, but both halves were easy using the OIII filter at 22x. The two halves wouldn’t quite fit in my 40mm eyepiece’s 3.1 degree field, but it was easy to sweep slightly back and forth to catch the whole nebula. This is a situation where the relatively short focal length of this scope really pays off.


The Orion® EON 120mm refractor proved to be an outstanding performer, optically and mechanically, on a wide variety of targets. The only problem I encountered was a little bit of slippage of the Crayford focuser under the weight of the 2” diagonal and eyepieces when pointing high overhead, but a slight tightening of a setscrew put that right. This is an extremely impressive telescope in every respect, showing fine optics, mechanical perfection, and sheer physical beauty. This telescope sets a new standard for performance and price.

Geoff Gaherty
Geoff has been a life-long telescope addict, and is active in many areas of visual observation; he is a moderator of the Yahoo "Talking Telescopes" group.

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A Heavenly Choir of Angles

If you're an amateur astronomer without any formal scientific training, some of the math involved might look like magic spells. Let's face it, you can be interested in science and nature even if you weren't good at math in school. You might even be one of those people who is perfectly capable of mathematical thinking as long as you have a context for it. Read on for the first installment of a series of articles designed to help you catch up on a few morsels that will vastly help your understanding of astronomy.

Draw two straight lines that are not parallel to each other. Make one end of one line touch one end of the other line, in any orientation. You have just drawn an angle.

Here are two examples:

The red lines form a smaller angle than the blue lines do. This has nothing to do with the length of the lines or how far apart the 'ends' of the lines are. Even if you were to chop off the free ends of any or all of those lines, the angles between each pair of lines would remain the same. All that matters is the direction of the two lines relative to each other.

If you're standing on Earth and you can see two stars in the sky, you can imagine that two lines meet at your location and extend out towards those stars.

The angle between those two lines is a convenient way to express how far apart two stars appear to be in the sky. Again, forget about the length of the lines or the distance to either of those stars. Imagine that the sky is a dome over your head, or that the Earth is sitting at the centre of a sphere and the stars are painted all over the inside of it. (They're really far away, of course, and one of them is likely to be much farther away than the other, but for the purposes of measuring their separation on the sky, we don't need to know the true distances to them.)

We need some objective way of measuring this angle, something that can be communicated to someone else or written down for future reference. Just as you use miles or kilometers to measure distance between places, you need a unit of measurement to measure angles. The most common one is the degree.

Draw a circle and mark the exact centre. You'll notice that if you draw two lines that cut a wedge into the circle, starting at the middle and going to the edge as if you were cutting a slice of pie, there will be an angle between those two lines.

If you were to cut three hundred and sixty equal slices from this pie, each slice would have an angle of one degree—again, regardless of how big the pie is; similarly, any size of pie can be cut into four equal pieces, and the pieces are called quarters.

Now, whenever you look at two stars and you want to know how far apart they are on your sky, you can measure the angle between them and say how many degrees it is. Imagine that the two stars are sitting on a hoop, and you're at the centre of the hoop. Measuring their separation in degrees is like measuring how far around the circle you have to go to get from one to the other.

If you need more precise measurements, each degree can be divided into sixty arcminutes, and each arcminute can be divided into sixty arcseconds.

Now, when you see the Moon setting, you can tell someone how far above the horizon it is. I've heard people try to measure such things in inches. If you hold a ruler up and look at the sky, an inch will cover more sky if you have short arms, and less sky if you have long arms! This doesn't work. A good estimate is that your hand spread wide at arm's length is about twenty-five degrees from thumb-tip to pinky-finger-tip. If you have short arms you probably also have smaller hands, so this works better than a ruler.

Your pinky finger held up at arm's length is about one degree wide. If you know that a galaxy is a certain number of arcminutes across, you can decide whether you want to use high or low magnification to look at it.

Next month we'll cover some more advanced applications of this geometry, like latitude, longitude, and celestial coordinates.

Brenda Shaw
Brenda is an avid stargazer who enjoys guiding everyone to the stars, sharing her passion and knowledge with others.

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Pluto by Any Other Name

You may remember that in August of 2006, the International Astronomical Union (IAU) caused quite a stir by reclassifying Pluto as a dwarf planet. This was mostly due to the discovery of a host of large, asteroid-like objects beyond the orbit of Pluto. One of these, now called Eris, was actually larger than Pluto! Thus, to avoid a huge increase in the number of planets (as was the case in the mid 1800’s)1, the new category of dwarf planets was created.

On June 11, 2008, the IAU decided to designate Pluto as a “plutoid”. As well, any other dwarf planet candidate that was further from the Sun than Neptune would also be a plutoid. That means Eris (further from the Sun than Neptune) is a plutoid but Ceres (between Mars and Jupiter) is not.

What about some of the other bodies orbiting the Sun beyond Neptune in the so-called Kuiper belt? Well, if any such object is bright enough (absolute magnitude brighter than H = +1)2, it becomes a plutoid, at least temporarily. If further studies indicate the object is not massive enough, it loses its “plutoid” status.

In a nutshell, then, a plutoid appears to be a dwarf planet that orbits the Sun beyond Neptune. Why then come up with a new term? Probably because the definition of a plutoid is not as nebulous as the definition of a dwarf planet.

Here then is the current situation:

  • 8 planets (P): Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
  • 1 dwarf planet (dP): Ceres
  • 2 plutoids (p): Pluto, Eris
  • 160+ planetary satellites
  • Numerous small solar system bodies

Is this the end of the story? Hmmm.... Stay tuned!


  • For more background information on the number of planets in the solar system, see my article Alas, Poor Pluto in the October 2006 issue of Starry Night® Times
  • H is the absolute magnitude for planets; not to be confused with M, the stellar absolute magnitude. H = apparent magnitude of planet-like object at distance of 1 AU. M = apparent magnitude of stellar object at 10 parsecs. (e.g. H for Pluto = -0.7, M for Sun = +4.8)

Herb Koller
Education Consultant for Imaginova

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Constellation in Focus: Hercules

Constellation Map: Hercules

The fifth largest constellation in the sky, Hercules is perhaps most famous because of the Great Hercules Cluster, M13, perhaps the most prominent of globulars visible to northern hemisphere observers.

At least 149 globular clusters in the Milky Way have been discovered, and more than 100 are in the NGC-IC catalog. Their distribution forms a spherical halo, centered on the core of our Milky Way. "Globs" are densely packed balls of stars. Up to two million stars can be found bound together with a radius of no more than 100 light years.

The Great Hercules Cluster is visible to the naked eye at dark sites. The glob is about 14 billion years old and contains more than a million suns.

Because of its proximity to M13, M92 is often overlooked even though it's one of the brighter clusters available to northern viewers. One of Johann Elert Bode's discoveries in 1777, it was rediscovered by Charles Messier in 1781 and has been clocked speeding toward us at 112 km/sec.

NGC 6229 is another globular cluster that's worth a look. Mistaken for a nebula by Herschel in 1787, it was revealed to be a "very crowded cluster" in the mid 1800s.

NGC 6210 is a planetary nebula, a sun not unlike our own in the final stages of its life. It has a very high surface brightness and is a good target for high magnification.

Sean O'Dwyer
Starry Night® Times Editor

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Astrophoto of the Month

Astrophoto of the Month

Name: Christopher J. Plasch
Object: M13, The Great Hercules Cluster
Taken: 6/10/2008, Yorkville, IL- My backyard

  • Orion® XT-10 mounted on an Atlas EQ-G driven by Starry Night Pro 6
  • ST-80 with Starshoot Autoguider
  • Canon Rebel XTi, unmodified

Picture Details:

  • Number of subs: 10 @ 3:00 min each
  • Total Time: 30 minutes
  • ISO: 800
  • No filters
  • Processed with DeepSkyStacker and Photoshop CS3



We would like to invite all Starry Night® users to send their quality astronomy photographs to be considered for use in our monthly newsletter.

  • Featured submissions (best of month) will receive a prize of $75 USD.

Please read the following guidelines and see the submission e-mail address below.

  • Format: Digital images in either JPG, GIF or TIFF format.
  • Size: 700 pixels wide maximum.
  • File size should be less than 2 MB.
  • Include a caption: Your full name, location where photo was taken and any interesting details regarding your photo or how you took it. Please be brief.
  • Important notes: We may edit captions for clarity and brevity. We reserve the right to not use submissions. In submitting your image or images to Imaginova®, you agree to allow us to publish them in all media—on the Web or otherwise—now and in the future. We'll credit you, of course. Most important, you'll have the satisfaction of sharing your experience with the world!
  • Send images, following the above guidelines, to (by sending an image you agree to the above terms, including Imaginova®’s right to publish your photos). Please do not send .ZIP files as they will not reach us.

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JUL 2008

Starry Night 6.2 with FREE shipping!
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Free Download

Mars Phoenix Space Mission

NASA Mars Lander

1) Download the Mars Phoenix Spacecraft 3D Model, unzip the files and place in the Sky Data/Models folder.

2) Download the Mars Phoenix Spacecraft Trajectory Data and place in the Sky Data/Space Missions folder.


In Windows you can find the Sky Data folder under Starry Night <product name>\Sky Data on your local hard drive.

On a Mac, Ctrl-click on the Starry Night application and select "Show Package Contents" from its contextual menu. Open the Contents-Resources-Sky Data folder.

To view the Mars Phoenix Spacecraft, open the Find Pane in Starry Night and do a
search for Phoenix.

Pedro Braganca
Content Director,
Starry Night®


Free Download
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Sky Events

A guided video tour of celestial events visible this month.

  • Click Here to Download


Tips Tricks
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Tips & Tricks

The Sky on the Day You Were Born

Just go to and add the Starry Night® Birthday Sky application to your account. Find out what was up in the sky on the day you were born.

Pedro Braganca
Content Director,
Starry Night®

Tips Tricks
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Sky Events

Moon Phases

Wed., Jul. 2
New Moon , 10:19 p.m.

"New" just signifies that the Moon has started a new cycle, but you can also refer to this as "No" Moon since it is not visible at the time. See July 1 below.

Thu., Jul. 10
First Quarter Moon, 12:35 a.m.

As usual, this letter "D" Moon is well up in the South at sunset, and sets about halfway between sunset and sunrise.

Fri., Jul. 18
Full Moon, 3:59 a.m.

The Full Moons of Summer mirror the Sun in Winter. In other words, they make short, low tracks across the southern sky. All the various full moons of the year had names given to them by American Indian (First Nations) tribes, as well as by other cultures around the world. According to Kim Long in The Moon Book (Johnson Books, Boulder, 1998), the 7th Full Moon of the year was known as the "Buck Moon" or "Thunder Moon" by the Algonquin; "The Time of Much Ripening" by the Mohawk; and "The Moon When Everything is Born" by the Tlingit.

Fri., Jul. 25
Last Quarter Moon, 2:42 p.m.

"Last" here does not mean that the Moon is gone for good, but merely that it has reached the last major phase in its current cycle. This is also referred to as the "Third" Quarter, when the Moon is 75 percent of the way through the cycle. Last Quarter Moons rise at roughly (very roughly) midnight and set at (again, very roughly) noon the following day.

Observing Highlights

Sun., Jul. 6
Moon-Saturn-Mars, evening

The Moon passes to the left (south) of Mars and Saturn (in Leo) this evening, in the western evening sky.

Mon., Jul. 28
South Delta Aquarids peak, 4:00 p.m.

This is, as things go, a relatively minor meteor shower. The best time to look is several hours before dawn, toward the southern skies. The radiant, or point from which the meteors seem to radiate, is in the southern part of the constellation Aquarius, but the meteors appear in a wide region of sky. Their paths, if traced backwards, converge at the radiant.


Mercury starts the month with the thin Crescent Moon nearby (a few degrees to the upper left), low in the predawn eastern sky, among the stars of Taurus. At greatest western elongation on the first, it stands some 22 degrees from the Sun, but this distance diminishes (and viewing opportunities worsen) as the month goes on. By mid-month observing is difficult and shortly thereafter impossible, as the planet moves on to superior conjunction behind the Sun on the 29th.

Venus has been lost in the solar glare since the latter part of May, when it was in the morning eastern sky. But by mid-July it emerges back into the western evening twilight, setting less than an hour after the Sun. Observational opportunities improve through the rest of the year.

Mars, along with Saturn, is in Leo, sinking into the western evening twilight. It also is slowly getting dimmer as it recedes from Earth, heading for a conjunction on the far side of the Sun in early December. It sets about two hours after the Sun at mid-month. Mars passes less than a degree from Saturn on the evening of the 10th.

Jupiter is the undisputed king of the night. It typically outshines all other planets except Venus and, rarely, Mars. At magnitude -2.7 and no rivals to be seen late at night, Jupiter is a stunning sight, blazing forth in Sagittarius. Look for it low in the southeast in the early evening, to the South late at night, and in the southwest before dawn. At opposition (opposite the Sun in the sky) on the 9th, it rises at sunset and sets at sunrise. A small telescope can provide hours of fascination as the planet's glimmering moons accompany it.

Saturn is low in the West at sunset, soon to be lost in the glare of the Sun. At magnitude 0.8, it is roughly twice as bright as nearby Mars (magnitude 1.7), but the lowness in the sky and the twilight glow conspire to make it less than a knockout. Determined observers can still observe the rings, but the ring tilt is steadily decreasing such that it will be edge on -- and perhaps impossible to see -- by early 2009.


Tue., Jul. 1
Mars-Regulus, 12:00 a.m.

Closing in on Saturn for a conjunction of less than a degree on July 10, Mars passes less than a degree to the North of Regulus in Leo tonight (Monday night - Tuesday night).

Tue., Jul. 1
Mercury at Greatest elongation west, 1:54 p.m.

Mercury is at its greatest distance to the western side of the Sun, about 22 degrees. Being to the West of the Sun means that it is in the eastern morning sky. It is not particularly well placed, but you might catch it very low in the East-northeast, in Taurus, about an hour before the Sun.

Tue., Jul. 1
Moon at Perigee, 4:28 p.m.

As in early July, the Moon reaches perigee (closest to the Earth) at nearly the same time it is lined up with the Sun as a "New Moon" (tomorrow). This tends to increase its affect on the tides, and so the high tides at this phase may be bigger than usual. This time the Moon is just over 56 Earth radii away, or about 223,400 miles.

Fri., Jul. 4
Earth at Aphelion, 3:55 a.m.

The Earth's distance from the Sun varies a bit through the year, and it may come as a surprise to some that we are actually farthest in early July, by about one or two percent from the average. Today the Earth is 1.01676 Astronomical Units from the Sun, or about 94,514,000 miles

Fri., Jul. 4
Moon-Beehive, 5:00 p.m.

This happens in broad daylight and cannot be directly observed in North America. However, shortly after sunset the Moon and the Beehive (M44) star cluster will be close, low in the western sky. From most of North America, the lunar crescent will be slightly to the left of the star cluster. The latter will be particularly difficult to see due to solar glare and nearness to the horizon. Try binoculars.

Wed., Jul. 9
Jupiter Opposition, 3:36 a.m.

Jupiter is at opposition, meaning that it is roughly opposite the Sun in the sky, analogous to the situation with a Full Moon. Thus it rises at about sunset and sets at about sunrise. if you think about the geometry, it is also at its closest to the Earth. These factors combine to make Jupiter its brightest, at about -2.7 magnitude, which is about as bright as it can get. Unfortunately, it is nearly as far South as it can possibly get, so the relative lowness to the horizon cuts the effective brightness.

Fri., Jul. 11
Mars-Saturn, 2:27 a.m.

Mars passes about 3/4 of a degree South of Saturn. Unfortunately, this may be after both planets set as seen from many locations, but the view before setting (roughly 11 p.m. local time) is nearly as good. Look low in the West in late evening. Mars is just to the left of brighter Saturn, in Leo.

Mon., Jul. 14
Moon-Antares, 8:00 a.m.

Moon passes about a third of a degree South of Antares. This actually occurs after moonset for North American locations, but the Moon is in a close approach to the star shortly after midnight on Monday morning, in the southwest sky. This event occurs as an occultation from parts of Australia, Polynesia, but this is not visible from North America.

Thu., Jul. 17
Moon-Jupiter, 8:23 a.m.

The Moon, nearly Full, passes less than 3 degrees from Jupiter. Unfortunately this is several hours after moonset from most locations. However, the view several hours earlier, to the Southwest, is nearly as good.

Sun., Jul. 27
Moon-Pleiades, 12:00 p.m.

The Waning Gibbous Moon passes slightly more than a degree North of the Pleiades. Of course this is midday throughout North America, but look to the eastern heavens shortly before first light.

Tue., Jul. 29
Mercury at superior conjunction, 4:07 p.m.

Superior conjunction means that the planet is in line with the Sun, but on the far side of the Sun. At this moment that planet cannot be seen, but it is important because it marks the moment when the planet moves from the morning sky to the evening sky. However, it likely will not be visible in the evening until at least mid-August.

Fri., Aug. 1
New Moon, 6:13 a.m.

As always, New Moons are too near the Sun to be seen. However, sharp-eyed observers may be able to catch a very thin crescent in the western sky after sunset on the day following (Saturday). The second day following (Sunday) should be easier.

Fri., Aug. 1
Total Solar eclipse, 6:22 a.m.

Unfortunately this total solar eclipse is not observable at all from most of North America. However, a small portion is visible from far northeastern Canada and northern Greenland. The greatest eclipse is at 6:22 a.m. EDT. The best locations are in Europe and Asia. For details, see the NASA Eclipse web page.

Sat., Aug. 2
Moon-Venus, 11 a.m.

An extremely thin Crescent Moon passes about 2 degrees South of Venus at this time, which unfortunately cannot be seen because of daylight. However, just after sunset, observers with keen eyesight and excellent conditions may be able to catch the fingernail crescent several degrees to the left of pinpoint Venus, very low in the western twilight.

Sun., Aug. 3
Moon-Mars, evening twilight

The Crescent Moon passes about 4 degrees below Mars, low in western evening twilight.

As always, there's more to explore on NightSky.

Data for this calendar has been derived from a number of sources including the Observer's Handbook 2008 of the Royal Astronomical Society of Canada, Starry Night® software, and others. Only events with a reasonable possibility for Northern Hemisphere observers, or those events with some other significance, are given. All times shown are U.S. Eastern Time.

Sky Events
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