Archive for January 2012

Observing With Two Popular Beginner Telescopes: Orion 100mm SkyScanner And 76mm (Model 21024) Celestron FirstScope

January 29, 2012


M82 - 76mm

NGC 1502 & Kemble's Cascade-1



My granddaughter was visiting from out of town, and the forecast was clear skies.   I thought this might be the perfect opportunity to share the night sky with Gracie.  It also occurred to me that this would be a good time to see how easy it would be for an eleven year old to use two very popular beginner telescopes.  A 76mm Celestron firstScope and a 100mm Orion SkyScanner. 

The 76mm Celestron FirstScope (model 21024) has a 300mm focal length for an f/4.0 focal ratio.  It comes with two eyepieces for magnifications of 15x and 75x.  

The 100mm Orion SkyScanner has a 400 mm focal length for an f/4.0 focal ratio also.  The Orion scope has a parabolic mirror, and the FirstScope has a spherical mirror.  A parabolic mirror (especially at f/4) should have better performance than a spherically ground mirror.  The SkyScanner eyepieces are quite a bit better in quality than the ones which come with the 76 mm FirstScope.  

The 76mm Celestron sells for about $50 from a variety of vendors, and the 100mm Orion SkyScanner…at current sells for $119.00 from Orion Telescope and Binocular.   

Both scopes performed well, with the biggest difference being brighter views in the 100mm versus the 76mm, as expected due to the larger aperture.      

It should be noted that the Celestron FirstScope does not come with a finder.  The 100mm Orion SkyScanner comes standard with a very good quality red-dot finder that works really well.  I have a couple of Rigel Quik Finders, so I use one with my FirstScope.  The mounts are well constructed, and both scopes can be moved very smoothly and with precision.  

Note:  To effectively use the 76mm FirstScope, a finder is essential.  You can purchase an optional “optical” finder kit, with a DVD for (about $20) but it’s a bit too small and dim, so I can’t recommend this finder.     

The Orion SkyScanner 100 comes standard with a an excellent red dot finder, better quality eyepieces, and a parabolic mirror.  The SkyScanner has almost twice the light gathering capacity, and is just as portable.  

Both telescopes offer excellent value for the money, however, if you can spring for the extra money, the Orion SkyScanner offers quite a bit more in performance and capability. 

 Back to observing:  

My granddaughter Gracie and I were able to observe quite a few deep-sky objects. We stayed out well over an hour with the temperature in the low 30’s.  She learned how to use the red dot finders, pointing the scopes, and focusing without any difficulty at all.  

Gracie could see the red star (known as the Espin Star) located in the central region of M41 in the 100mm SkyScanner, and galaxies M81-82 were very easy in both telescopes.  She described the two galaxies very well, “one is mostly round and the other is oval” and this was without any coaching.  She became very interested in learning about red stars and even pointed out a couple without a telescope.

On Sunday morning before church, she filled out three note cards with her thoughts and descriptions from the previous night.  She mentioned the Espin star in M41, her perception of open cluster M45, the moon, Jupiter, M42 and the Trapezium.  Gracie said she understood the purpose and importance of using a red light when observing.  She had leaned about this in a book she had read.  I was very impressed!

Her last sentence in her notes: 

“Then I looked at M81 & M82, it was a pretty cool night.”   Gracie 

Both scopes presented a nice and crisp separation of the four trapezium stars in the Orion nebula.  

You can purchase larger and better telescopes, but at $50 and $110 respectively, one cannot go wrong with either of these telescopes.  If you find that amateur astronomy is not your cup of tea…well, you haven’t lost a great amount of money.  However, if it is, there are plenty of telescopes to move up to, and I’ve always believed that everyone should keep their first telescope. 

Final:  Not only are these scopes of very good quality and perform well, they also look great sitting on a bookshelf or desk.  

 Roger Ivester 

NGC 1502 Open Cluster and Kemble’s Cascade In Camelopardalis As Observed Through a 76 mm f/4 Reflector

January 16, 2012

NGC 1502 & Kemble's Cascade-1

NGC 1502 and Kemble’s Cascade

Date: January 15th 2012

Conditions: Excellent

Location: Moderately light polluted backyard in western North Carolina

 76 mm f/4 Dobsonian Reflector, using a 24 eyepiece with 60 degree apparent FOV.  Magnification 13x. 

Telescope:  5.0 degree true field

Faint patch and little resolve of stars.  Double star Struve 485 is in the center of the cluster and appears as a single bright star at low magnification. The cluster is triangular in shape, and fairly easy to see in the small reflector.  This scope presents Kemble’s Cascade as a beautiful and interesting chain of  fifteen stars, with one brighter star noted in the line. 

It was important to me to observe this months Observer’s Challenge Object with this small and inexpensive scope.  I wanted to show that the best scope is not necessarily the finest or most expensive, but the scope that is used most often. 


Amateur Astronomy With a $50 Telescope?

January 16, 2012

NGC 1502 76 mm Reflector-1

NGC 1502 Open Cluster in Camelopardalis

Telescope:  76 mm Celestron FirstScope @ 70x

M33 (NGC 598) Spiral Galaxy

January 9, 2012

Observation date: November 16th 1995:

Conditions:  Excellent

Location:  Moderately light polluted backyard  NELM 6.0;  Telescope:  10-inch f/4.5 reflector;  Magnification:  57x with 1 degree FOV.  Description:  Large and faint with low surface brightness, elongated NC-SW, and a brighter more concentrated middle.  Two spiral arms could be seen with careful observing and averted vision.  One arm was noted on the SE edge and the other on the NW, however, both were very subtle  The texture of the galaxy is very uneven, and several knots could be seen intermittently during moments of steady viewing.  The outer regions fade very gradually outwards.  The brightest HII region of the galaxy, identified as NGC 604, appears bright with an irregular oval shape, and a faint star situated very closely toward the east.

November 18th 1997:  Conditions:  Fair, both seeing and transparency; Moderately light polluted backyard; NELM 5.0  Telescope:  3.5-inch Maksutov; Magnification:  52x  Description:  Brighter middle, large, faint, and elongated.

October 16th 1998:  Conditions:  Good; Location:  Backyard; NELM 5.5  Telescope:  102 mm refractor; Magnification:  42x  Description:  Large, faint, brighter more concentrated middle, very low surface brightness with an elongated shape.  The texture appears very uniform.  This is not an easy object, and would be best observed from a dark site.