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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: davidpitre]
      #5783920 - 04/07/13 02:26 PM

I would agree, David.

But it is what it is. More important than the "absolute" rating, however, is whether the "relativity" of the ratings is accurate. In other words, you have two targets, one ranked "difficult" and the other "very challenging" (which is two notches harder on the ST3 ratings scale). Even is one is really "obvious" and the other "difficult" (i.e., two notches harder), the rating system has some value. Maybe it's just not very well calibrated.

Also, the rating system around double stars is a little wonky in its own right. When using the database power search feature and there are actually two different "difficulty"-like filtering systems - one for visibility and the other for splitability. I sometimes forget to modify one or the other and then get funny results in the generated list columns.

Still, it's a handy tool for sorting and such. Oh, I also normalized the list for a spring night in 2013 (on the theory that spring is Messier Marathon season and offers as good a range of dates as any for generating a year-round list. That might have been an erroneous assumption, but it is what it is. In any case, plenty to chase.

Regards,

Jim


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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: Astrojensen]
      #5783955 - 04/07/13 02:42 PM

"I do think it's quite a big deal not to include big, famous objects that are easily visible, while including several that are extremely faint and difficult."

That's where we differ. Anything that inspires folks to try out too-often underestimated small aperture on any group of targets is worthwhile. The list could have had 50 targets or 10,000 targets, and from the perspective kindling interest in the format would have been just as useful.

Besides, Herschel's list includes many erroneous listings (i.e., no object at the position given) and also omits objects that were within the capability of his equipment. So too Messier did not catalog every object that it would have been possible for him to observe. The challenge list is in that sense in good company.

Regards,

Jim

Edited by jrbarnett (04/07/13 02:45 PM)


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Astrojensen
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Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5784115 - 04/07/13 03:41 PM

Quote:

Anything that inspires folks to try out too-often underestimated small aperture on any group of targets is worthwhile.




True, but why then confuse them with near-impossible targets? Or even nonexisting ones?

I think the list is a great idea, make no mistake, but it desperately needs revision in my opinion, to weed out nonexisting objects and very faint ones that are out of range of a 60mm, unless you stick a CCD on it.

I've made such a list some years ago, actually. It's in the 60mm Club archives somewhere. I actually made two lists. One with only easy objects and one also with faint objects, also threshold ones, with galaxies to mag 11.5 and planetary nebulae to mag 13. It has over 1100 objects. I have not seen every object on them, of course, but I weeded the list as well as I could, using DSS to check dubious cases, such as anonymous PGC galaxies or the MCG "galaxies" in Orion (they're actually small diffuse and reflection nebulae).

Since some time back, I've been working on a ~100 object list with non-messier deep-sky objects for a 60mm that I've actually observed. Mostly bright objects that are easy to see, but with a few challenges for a dark sky thrown in here and there. Sort of a "Hidden Treasure" list for 60mm scopes.


Clear skies!
Thomas, Denmark


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t.r.
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Reged: 02/14/08

Loc: Upstate NY
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5784183 - 04/07/13 04:08 PM

I'm surprised that the Astro League doesn't have a 60mm observing program, long overdue.

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Astrojensen
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Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: t.r.]
      #5784248 - 04/07/13 04:30 PM

Quote:

I'm surprised that the Astro League doesn't have a 60mm observing program, long overdue.




Now that you mention it. They really should have. Perhaps they think the Messier list suffices?


Clear skies!
Thomas, Denmark


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Chuck Hards
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Reged: 05/03/10

Loc: The Great Basin
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5784256 - 04/07/13 04:33 PM

I had planned to try some difficult solar system objects as well, such as planetary satellites and minor planets. Any interest?

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Astrojensen
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Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: Astrojensen]
      #5784257 - 04/07/13 04:33 PM

BTW, I was reading through Jim's list, when I discovered that it's slightly less than 50 pages long, not 65, as the DSO part is listed twice... It begins anew on page 49!


Clear skies!
Thomas, Denmark


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Astrojensen
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Reged: 10/05/08

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Re: The Year-Long 60mm Telescope Challenge new [Re: Chuck Hards]
      #5784260 - 04/07/13 04:34 PM

Quote:

I had planned to try some difficult solar system objects as well, such as planetary satellites and minor planets. Any interest?




You bet! Go for it!


Clear skies!
Thomas, Denmark


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Astrojensen
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Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5784286 - 04/07/13 04:49 PM

Quote:

More important than the "absolute" rating, however, is whether the "relativity" of the ratings is accurate.




It isn't. I've looked at the list and how can it list a NAKED EYE STAR CLUSTER such as fifth-magnitude M41 as "Difficult"???? And M35 is only "detectable"... In a 60mm? And there are literally dozens of such examples.

To me, at least, "detectable" means something is very, very faint and barely visible with great effort, it is beyond challenging, shows no details other than a very faint smudge, perhaps with some elongation, but no other details. We are talking naked eye open clusters here, for spaghetti's sake.

But I guess I need to walk the walk and not just talk and talk and actually come up with a better list.


Clear skies!
Thomas, Denmark


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Chuck Hards
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Loc: The Great Basin
Re: The Year-Long 60mm Telescope Challenge new [Re: Astrojensen]
      #5784301 - 04/07/13 04:55 PM

It should be remembered that "difficulty" can be considered a moving target. Aperture aside, image scale (magnification and field of view) can play a huge role in how visible an object is. Something that is borderline in a small telescope can suddenly become almost obvious if the right eyepiece is used. One of my first "discoveries" as a rank beginner all those decades ago.

It's part of the challenge.


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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: Astrojensen]
      #5784369 - 04/07/13 05:28 PM

Bah! Formatting. Moving ST3 data into MS-Word tables. Part of the double star list, too, is duplicated I see. Sorry. I can update it on Monday. All Mac OS X at home; no Sky Tools.

However, the list is the list for this exercise. As clearly stated in the article, this is *not* supposed to be a comprehensive list of everything you can see in a 60mm telescope, nor is there any guarantee that it's possible to see everything on this list in a 60mm (many targets will, indeed, be *very challenging* even factoring in ST3's pessimistic rankings). From the article:

"Below is a carefully considered list of targets that *may* be within reach of a 60mm telescope to a middle-aged experienced observer under typical suburban skies. The list was constructed using thoughtful, deliberate filtering in SkyTools 3 normalized for my home observing site at 38N. It does not necessarily list every target potentially visible in a 60mm. Nor is every target on the list necessarily visible to anyone, anywhere, in a 60mm telescope."

The objective of the challenge is NOT to assemble a 60mm "best targets" list. Rather it is to push participants to try and find the limits of a 60mm telescope and, hopefully, come away with the sense that 60mm is larger and more competent than they expected or, if they cut their teeth with such a scope, more capable than they remembered .

Regards,

Jim

Edited by jrbarnett (04/07/13 05:37 PM)


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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: Astrojensen]
      #5784401 - 04/07/13 05:49 PM

Or maybe the "Urban Observers Program".

Here are the 60mm scopes I plan on using for the effort:











Granted the mount is a bit nicer than the one that my old Jason came with.

Regards,

Jim

Edited by jrbarnett (04/07/13 05:50 PM)


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Astrojensen
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Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: Chuck Hards]
      #5784409 - 04/07/13 05:54 PM

Quote:

It should be remembered that "difficulty" can be considered a moving target. Aperture aside, image scale (magnification and field of view) can play a huge role in how visible an object is. Something that is borderline in a small telescope can suddenly become almost obvious if the right eyepiece is used. One of my first "discoveries" as a rank beginner all those decades ago.

It's part of the challenge.




Absolutely true.


Clear skies!
Thomas, Denmark


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Astrojensen
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Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5784412 - 04/07/13 05:55 PM

Jim, that's an incredibly nice setup!


Clear skies!
Thomas, Denmark


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Astrojensen
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Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5784438 - 04/07/13 06:05 PM

Quote:

As clearly stated in the article, this is *not* supposed to be a comprehensive list of everything you can see in a 60mm telescope




Such a list is incredibly difficult to make, since the observer's skill is a moving target and with increased skill, you can see fainter and fainter objects, so the list needs to get bigger and bigger. It was in no way my intention to suggest that your list was trying to be a comprehensive list of objects for a 60mm.

But I still thinks it needs to be scrutinized and the errors removed. Some of them are genuine catalog errors, such as stars instead of galaxies and such. That PGC galaxy in Andromeda is a star, for example.


Clear skies!
Thomas, Denmark


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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: Astrojensen]
      #5784598 - 04/07/13 07:30 PM

Actually perhaps flagging the errors in the list would be of assistance to the Sky Tools 3 author as the classifications are all based on the designations in the application.

Regards,

Jim


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Astrojensen
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Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5785239 - 04/08/13 02:59 AM

Quote:

Actually perhaps flagging the errors in the list would be of assistance to the Sky Tools 3 author as the classifications are all based on the designations in the application.




Good idea.

BTW, I am working very early in the morning this week, or else I would be out there with the 63mm, bagging stuff from the list. I have a day off today, but of course it was cloudy yesterday evening.


Clear skies!
Thomas, Denmark


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yashi
super member


Reged: 11/15/11

Re: The Year-Long 60mm Telescope Challenge new [Re: Astrojensen]
      #5785573 - 04/08/13 10:22 AM

awesome idea

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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: yashi]
      #5785633 - 04/08/13 10:54 AM Attachment (72 downloads)

Thank you yashi.

I'm have an updated 60mm Challenge List, modified to remove duplications in both the double star and DSO sub-lists. I'll see about getting the version embedded in the article replaced with this one. 33 pages is more manageable than 65. Unfortunately it is too large to attach to forum posts, even if I publish it as two lists; one for multiples/doubles and another for DSOs. In the meantime, if you would like the updated list in either PDF or Doc format, let me know by PM and I will e-mail it to you.

I should also clarify that the difficulty rating scale for DSOs in ST3 ranges like this, from easiest to hardest:

Easy->Obvious->Detectable->Difficult->Challenging->Very Challenging

One other thing to bear in mind is this. The list was generated using the optimal date for a Messier Marathon as the reference date in the tool. When the complex difficulty rating model is applied to the filter data, including this date at my site, targets that don't get out of the soup will reflect a higher difficulty rating than they would at a time of year where that target is at or near the meridian.

The difficulty ratings are only one guideline. Using the stated magnitude, too, may be helpful. I can also generate and provide custom formatted tables with other information columns (alternate names, dimensions of object, relative surface brightness, etc.), but went with the format in the article for simplicity. PM me if you'd like a different cut of the data.

EDIT: I've attached the updated list with redundancies eliminated to this post in Rich Text Format. Everyone should feel free to do whatever you like with the data table and its format.

Regards,

Jim

Edited by jrbarnett (04/08/13 11:37 AM)


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Jim Romanski
Carpal Tunnel
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Reged: 01/02/05

Loc: Guilford, Connecticut
Re: The Year-Long 60mm Telescope Challenge [Re: jrbarnett]
      #5785673 - 04/08/13 11:07 AM

What fun! Nice idea Jim. I never had a small refractor as a kid. I started out with a 100mm Celestron SCT that my Dad let me use.

I do remember fondly a camping trip to the Black Canyon of the Gunnison in Colorado. It was extremely dark in the Canyon. M6 and M7 were ablaze it seemed. All I had was a 7x35 Fujinon binoculars. I was surprised to be able to sweep up about 35 Messier objects just sitting at the picnic table. Even the little globulars under the Teapot in Sagittarius at 7X. Dark and dry skies can do wonders for your observing.

Not sure what instrument(s) I'll use. Gotta knock off 3mm from my AT72.
So what if you use a 60mm refractor and mount a really BIG eyepiece on the other end. But then you look through the 60mm objective and out through the eyepiece...would that be cheating?


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