Posts Made By: Herbert Kraus

Bill: After sending you my previous post in response to your inquiry, I looked up SkyCommander in the Internet and learned that it is indeed a DSC, but the catalogs in its database do not include any part of the SAO or other catalog of individual stars. However, there is an "S" list in which you can program the coordinates of up to 59 objects of your own selection. To use this DSC for the carbon stars you're interested in, I would suggest you program their coordinates on this "S" list; those coordinates can be obtained from various sources, including the Belmont Society website I mentioned yesterday. Good luck. Herbert Kraus.

Lee: Taking into account that, according to your User Profile, the apertures of your scopes are 60 mm and 70 mm, I would suggest the following additional objects on a clear night this late April:
Open clusters M36, M37 (dim but vast) and M38 in Auriga, M35 in Gemini, M41 in Canis Major (early evening, before it sets) and M46 (dim) and M47 in Puppis. Globular Cluster M3 in Canes Venatici. Bright Double stars Castor in Gemini (challenging), Algieba in Leo (challenging) and Cor Caroli in Canes Venatici.
In my opinion (2 cents worth), you would be wasting your 30-minute time trying to see any galaxies with scopes of those apertures; the brightest one you might see is M81. Clear skies to you.

David: Based on a few years' experience with outreach programs to middle school pupils, I would emphatically confirm what some others have told you here: Your list of objects is already too long. With one telescope for 30 people and two hours' viewing time, you will find that four objects, viewed for half an hour each is ample (that allows each viewer one minute to observe each object). Also: include Saturn and Jupiter for sure, but I would forget Mars this month. And you may find that galaxies, as seen through an 8-inch telescope, would disappoint most of the 14-year olds, regardless of whatever fascinating lore you can impart to them about how large these objects are and how long it took their light to reach us. M44 by all means if you have a low-power wide-angle eyepiece that allows the kids to see most of it through your 8-inch scope; otherwise leave M44 to be viewed through the binoculars and use your scope for M37, M3, etc. (I think M4 and M57 will not be available or well positioned before 10:30 p.m. this Thursday, but M13 may be ok near the end of your session).

My experience with an older model of the NexStar 8i is this: When you have connected a power supply to the 12-volt power input -- whether you're using a portable power tank or an "AC adapter" (i.e., a transformer connected to an AC outlet) -- the telescope will draw its power from that source and the installed AA batteries will not disturb it. Those batteries themselves are ok for moving the scope's motors in altitude and azimuth while you are setting it up or taking it down, but don't rely on them for the actual work of aligning, slewing and tracking during an observing session; they are inadequate for those purposes.

Warren: The entire Veil Nebula would require a true field of view (TFOV) of at least 3º. I had the same wish to see that entire object in my 80 mm refractor a couple of years ago, and for about $100 I obtained a 30 mm BW-Optik 2-inch eyepiece from Anacortes that did the job.
But I don't think you can accomplish your objective with the 8-inch f 5.9 Newtonian. With a 30 mm eyepiece you would need one whose apparent field of view (AFOV) is about 120º, and I don't believe that exists; I think the best you could do is to get a TFOV of about 2º with a 41 mm eyepiece that has a 68º AFOV, like a Panoptic, but even that would cost much more than $100. Sorry about the negative response, but I think you alreay knew this answer.

Here's the second photo, showing the 60-inch scope viewing Jupiter at twilight.

Amy: I have a NexStar 8i and, although I've never had the problem you describe, I will pass along the following advice from "The NexStar User's Guide" by Michael W. Swanson:
"If you have problems with the power cord pulling loose when the scope slews, attach it to the fork arm with a large rubber band or a self-adhesive hook. Sometimes even this may not be enough. . . Many power cords seem to provide a good fit, but the inside hole of the connector is too large for the center post of the scope's power connector. One possible solution is to use a jeweler's screwdriver or a razor knife to GENTLY spread the center post of the power socket on the base of the telescope. Be careful not to twist the post as you perform this delicate operation -- you could break the connector inside the scope, necessitating replacement of the entire power socket. A better solution is to replace the connector on the power cord. The correct connector for NexStar scopes has an outside diameter for 5.5 mm and an inside diameter of 2.1 mm. While a loose-fitting connector might seem to work, hard-to-diagnose problems often occur."

It seems to me the problem isn't how many objects orbiting our sun are planets, but why the IAU needs to decide what the word "planet" (or its equivalent in other languages) means. That's up to the philologists who write dictionaries. I believe the IAU should classify all the objects known to orbit our sun or other stars by their physical or other scientific characteristics, as was done for galaxies in the last century. I would suggest that they coin a new name for these objects, like "stellites" as an abbreviation for "stellar satellites" (sort of like "quasars" for "quasi-stellar objects"). For starters I would think such a system of classification should differentiate the gaseous stellites from the rocky ones.

Dmitri: Of the multiple stars in the Trifid Nebula, the brightest is apparently the pair designated H N 40.

Joseph: Rükl's Atlas of the Moon indicates that the largest crater near the moon's southeastern rim is Petavius, which has a diameter of 177 km and a very prominent central peak. I suspect that's the one you saw and that you over-estimated the crater's diameter, since even Clavius -- which I believe is the biggest of the moon's craters (not including impact basins) -- is "only" 225 km in diameter.