Image of the day

Captured by
Adam Livingston

Seagull Nebula

My Account

New to Astromart?

Register an account...

Need Help?

Posts Made By: Herbert Kraus

January 14, 2004 01:13 PM Forum: Eyepieces

Advice sought regarding 2" eyepieces

Posted By Herbert Kraus

I just acquired an Orion 80mm ED refractor with a diagonal that will accept both 2" and 1-1/4" eyepieces. Heretofore I have been observing through an 8" SCT with 1-1/4" eyepieces of which I have a representative selection. If I were to get just one 2" eyepiece for my little refractor, one that might show me celestial objects I could not see as well with the 1-1/4" eyepieces on the SCT, what would you suggest?

February 16, 2004 06:53 PM Forum: Deep Sky Observing

A Mathematical Question for Observers

Posted By Herbert Kraus

This may not be the right forum for my question, but I could find no other forum that seems to fit. Question:
Is there a formula or algorithm to convert the celestial coordinates of any star or deep-sky object as of a specified earlier epoch into its coordinates as of a later epoch? As an example: Burnham's Celestial Handbook gives the coordinates of M78 as RA 5 hrs 44.2 mins and Decl. North 00º 02'. I know that the positions noted in that book were for the 1950 epoch and precession has changed them. In order to determine the coordinates of M78 as of now or the 2000 epoch, must I look them up in a more current source, or must I apply the data applicable to just this object in its catalog listings? Or is there some mathematical formula that I can program into a spreadsheet that will adjust the 1950 coordinates of any star or DSO for its precessional movement since that epoch? The question arises for me because I find Burnham's work ideally organized and written for my kind of observing, but, to search for some of the more dim objects Burnham lists, I would like to be able to feed their current coordinates into my "go-to" scope. Your responses will be appreciated.

August 24, 2004 12:46 PM Forum: Celestron

SAO objects in Celestron database

Posted By Herbert Kraus

A question: The NexStar computerized hand controller is/was advertised as containing a database of 40,000 objects, and one of the catalogs it lists is SAO (Smithsonian Astrophysical Observatory). The SAO catalog contains over 258,000 objects. Can anyone tell me what are the limiting criteria of the SAO objects available through Celestron's database?

September 1, 2004 09:32 AM Forum: Equipment Talk

John Dobson

Posted By Herbert Kraus

In case you missed it: The September 1 issue of The Wall Street Journal has an interesting article on page D10 about John Dobson, his work and his enormous influence on amateur astronomy.

November 8, 2004 07:44 PM Forum: Equipment Talk

Re: I Guess I'm Being Insincere...

Posted By Herbert Kraus

I recall that you used to be a very active participant in these AM forums who has been gone for a while. Notice that you can now "hide" those forums you may not be interested in. To revive your flagging devotion to amateur astronomy, I would suggest you "hide" the forums about equipment, various kinds of telescopes, eyepieces, filters, mounts, etc., etc., and limit yourself to the forums devoted to deep-sky objects, double stars and solar system sights; then follow up with your own observations of some of the objects discussed in those forums. As others in this thread have suggested, for many of us the excitement is not in the hardware, it's in the splendors of the skies. (For comic relief, you might occasionally visit the forums about politics, religion or philosophy, but not if you have high blood pressure). As they used to say: "clear skies!"

November 23, 2004 08:51 AM Forum: Eyepieces

Field Stop Specifications

Posted By Herbert Kraus

Could someone direct me to a website where I can obtain the comparative specifications, particularly including the field stop diameters, of the eyepieces offered by various commercial manufacturers (Meade, Celestron, University, etc., etc.)? These data are readily available for TeleVue eyepieces, but so far as I can tell the others will only disclose the focal length, size of the barrel and apparent field of view.

June 30, 2005 06:26 PM Forum: Deep Sky Observing

Did I Discover a Nova?

Posted By Herbert Kraus

Maybe some of you experienced deep-sky observers can check me out on the following: Wednesday night I was trying to observe the many globular clusters in Ophiuchus from our local dark sky site (Mt. Pinos). Seeking to observe NGC 6366 with a 15 mm Panoptic eyepiece in my 8-inch SCT (a 28 arcminute field of view at 135x), I saw a bright yellow star which I estimated at about 5th magnitude within or in front of what looked like a fairly extensive but otherwise rather dim globular, and when I slewed around the area a bit I saw nothing else that looked like a globular. I wondered whether I had discovered a nova! My later research reveals that NGC 6366 is of magnitude 9.2 or 9.5 or 10 and that its angular dimension is about 13 arcminutes (another source says 8.3), both data being consistent with what I saw behind or around the bright star, but also that it is 16 arcminutes away from 47 Ophiuchi, a magnitude 4.6 star (SAO 141665). I now suspect that I was looking at this star, that what I saw around or behind it was not a globular but some sort of reflection from the glow of this bright star, and that I simply missed the real NGC 6366, probably because the light from this dim object is spread too broadly across its fairly wide extent. I would be interested in anybody else's observations of my "nova." (There's a photo of NGC 6366 on page 89 of the July 1992 issue of Sky & Telescope).

July 19, 2005 09:38 PM Forum: Eyepieces

"Bivalent" Eyepieces

Posted By Herbert Kraus

This question has surely been asked and answered before, but I'm too lazy to do the research: When an eyepiece is configured to be used in either 1¼-inch or 2-inch diagonals or focusers, does it give a wider true field of view in its 2-inch than in its 1¼-inch configuration? Specifically, I note that Orion's new Stratus wide-field eyepieces, which some reviewers have indicated may be of pretty good quality at a reasonable price, can be fitted in both 1¼-inch and 2-inch focusers. Suppose I obtain a 17 mm Stratus e.p. and use it in an 80 mm refractor, would it make any difference if it rides in the diagonal's 2-inch barrel or in the diagonal's adaptor for 1¼-inch eyepieces?

August 17, 2005 09:31 AM Forum: Pictures of Me and My Telescope and........

The Leisurely Observer

Posted By Herbert Kraus

When the moon is near first quarter and too bright for observing DSOs, I study moonscapes by attaching an electronic eyepiece to the optical axis (the "Cassegrain" focus?) of a 3½-inch Questar and sending the images to a TV screen. This is a very comfortable way to learn lunography. (I'll post a second picture showing the telescope setup more closely).

August 30, 2005 09:20 AM Forum: After Dark

"John Dobson, high priest of amateur astronomy"

Posted By Herbert Kraus

That's the subject matter of an illustrated article in the Outdoor section of the Los Angeles Times for August 30, 2005. A companion piece describes a star party at Glacier Point in Yosemite.