TRG – Telescope Review Guide

Orion’s Skyquest XT4.5 is the smallest in their Dobsonian line of telescopes that includes the XT6 , XT8 , and XT10. Newcomers to the hobby are always surprised at how large amateur telescopes are, but to experienced observers, this XT4.5 is considered a very small scope. Tiny, in fact (It’s so small, astronomers are buying them just because they think they’re so cute). Make no mistake, though–the XT4.5 is a full-fledged telescope, and is a serious observing tool that could last you for years.

Your money buys you a lot in this case. Included are a good-quality 4.5″ f/8 primary mirror, two eyepieces, a finder, and a CD-ROM with a stripped-down version of The Sky, a software guide to the sky. The scope comes in two cartons. One contains the optical tube, and the other is a flat-packed box containing the base, which you assemble yourself. Orion includes all the hardware and tools you need, and the instructions are well written. Allocate about 30 minutes to assemble and align everything.

There are a couple of cost-cutting measures. The primary mirror is spherical, not parabolic (this is not likely to affect the views, however). Also, the focuser is plastic. Plastic focusers are naturally less robust than metal ones. Finally (and this may be the most serious concern of all), the scope is a little short for an adult. The eyepiece is only 3 feet off the ground, which may force you to stoop over (hint: try sitting on a short chair or stool while observing). On the other hand, the height is ideal for a child, making this a great telescope for kids.

Under the stars, the XT4.5 exhibits excellent performance. Once properly collimated (aligned), the optics give clear, sharp, contrasty views.  Jupiter’s cloud band and four moons are no problem to see, nor are Saturn’s rings. The Orion Nebula is a glowing fan of green gas, with a quartet of tiny stars at its core. Under dark skies (and with some diligence) the XT4.5 can even pull in some of the fainter deep sky objects, like the brighter galaxies in the Virgo Cluster.

As recently as a few years ago, the old adage regarding telescopes was that you must spend at least $300 to avoid buying junk. While this is still mostly true, Orion’s little XT4.5 breaks the price barrier in a big way. As long as you can deal with the short eyepiece height, it’s a great starter scope.

What can you see this month? A lot! So get out your best telescope or best binoculars and get to viewing!

May Sky on YouTube

Jupiter becomes more easily visible this month as its elevation in the pre-dawn sky is getting higher – about 23 degrees above the horizon by month’s end.   During May its separation from the Sun increases from 77 degrees to 101 degrees, and its magnitude slowly increases from -2.3 to -2.5.   It will lie just below the the last quarter Moon on the 17th in the pre-dawn sky.

Mars still remains low in the pre-dawn sky this month, but as it rises increasingly earlier than the Sun as the month progresses will become easier to spot.   It has a magnitude of +1.2.   By the end of the month, the angular separation from the Sun has increased to 40 degrees. We will have to wait a month or so until it will be seen easily in the pre-dawn sky.

Venus passed betwen the Earth and Sun in March so is now visible in the pre-dawn sky.   It will only lie 12 degrees above the horizon as the Sun rises on the first of May, so will be easier to spot later in the month.   It is at magnitude -4.4 at mid month, up and to the right of Mars.   In the middle of May, a small telescope will show a crescent phase equivalent to just before a first quarter Moon.   An interesting fact about its brightness is that it stays pretty constant at about -4.4 for most of the time that it is visible even though the apparent phase changes greatly.   When the phase is thin, Venus is nearer to us and the effective reflecting area of Venus as seen from Earth remains pretty constant.

Saturn is now high in the southern sky after nightfall in the constellation of Leo.  It lies well below the body of Leo.   It starts the month at magnitude +0.8 with an angular size of ~18.8 arc seconds and these fall to +0.9 and 18.1 as the month progresses.  Saturn is significantly less bright this year than it sometimes is: the rings are very close to edge on (as shown in the Hubble image of Saturn) and thus there is less apparent reflecting area.   During May they are at an angle of ~4 degrees from the line of sight.   The rings will be seen (or rather – not seen) edge-on later this year and it will not be until 2016 that they will be at their widest again.  A small telescope will easily show its largest moon, Titan, and show some bands around the surface.

Orion SkyView Pro 127 GoTo Mak-Cass Telescope
Here’s a telescope for the enthusiast who appreciates the practicality of a compact scope, yet wants the best features and performance available for the money. The Orion SkyView Pro 127 GoTo Mak-Cass Telescope comes with fully motorized GoTo computer control! After a simple alignment, a push of a button or two on the GoTo hand controller automatically points the telescope to one of 13,400+ celestial objects in its database. Dual stepper motors on the mount slew the telescope at a brisk 3.4° per second, centering your target right in the eyepiece. Easy!

The GoTo system consists of a computerized hand controller and two stepper motors that attach to the SkyView Pro telescope mount. What can you see with your Orion SkyView Pro 127 telescope? With intuitive menus and easy-to-use pushbutton controls, the GoTo system allows you to locate and track any object in its database of 13,400+ celestial objects including the entire Messier and NGC catalogs. You can use the GoTo controller to take a guided tour of the night sky or to pinpoint celestial highlights for the month. The GoTo hand controller requires an external 12-volt power source.

The SkyView Pro (SVP) 127’s high-resolution 5″ optics and 1540mm focal length (f/12.1) excel for high-magnification study of the lunar surface and planets. And it’s got enough aperture to display excellent astroimages of a wide variety of deep-sky jewels. The optical tube assembly is just 14.5″ long, making it wonderfully portable and easy to stow.

The Orion SkyView Pro 127 EQ mount provides fluid motion and a solid stance. 

If you are new to astronomy and aren’t familiar with where things are in the sky, then this is the best telescope for you! And the best part? You get to show others just how much of an astronomy expert you are when you can tell them the name of the object being viewed!

There’s a new comet passing nearby and it’s name is Lulin. This is when and how to find it.

On the night of February 23rd, in a moonless sky and near its peak brightness, Comet Lulin passes 2° south-southwest of Saturn.

Lulin’s closest approach to Earth, 61 million km, occurs on February 24th, when the comet may be at a peak of magnitude 5.0. By now it’s high up by late evening.

On the night of February 25th the comet goes through opposition, nearly 180° from the Sun in our sky. This means there mght be an “opposition effect”

brightening of its dusty coma and dust tail!

Path of Comet Lulin during February

After that Lulin moves away from both Earth and the Sun, fading quickly. The evening of February 27 will see it at about 6th magnitude within 1° of Regulus. Moonlight starts interfering again around the 28th.

Tails and Antitails

Because the comet stays nearly on the ecliptic, its tail (which points away from the Sun) aligns with the ecliptic and with the comet’s own direction of motion across the sky.

Moreover, because Earth remains in the comet’s own orbital plane, we see the comet with a very thin tail and an antitail, a spike pointing in almost the opposite direction from the main tail. Why? In three dimensions a comet’s dust tail is often wide but it’s always thin, confined to the comet’s orbital plane. When we are in or near this plane, we can sometimes see parts of the wide, thin dust tail on opposite sides of the comet’s head. We pass through most comets’ orbital planes briefly. This time, the situation will last and last.

A comet’s blue-green gas tail, on the other hand, always points nearly in a straight line away from the Sun in space. Cometary gas is blown directly away from the Sun at high speed by the solar wind.

MARCH: Following Lulin Out

Comet Lulin crosses from Leo into Cancer at the beginning of March and, having passed opposition, is now better seen in the evening than the morning hours however observers will have to contend with moonlight from about March 1st through 11th.

As Comet Lulin recedes, its passage across our sky will slow.  By May’s end it will be lost in the afterglow of sunset.

Comet Lulin won’t return again to the inner solar system for more than a thousand years.