Re: [guide-user] Guide Question

P. Clay Sherrod Apr 2, 2013

Go to DISPLAY on the tool bar and select Star Data...at the top is the setting for
your desired limiting magnitude. Note that as you increase that you will likely want
to turn the magnitude labels off because of the clutter on the screen. And, yes the
A2 catalog does go down to slightly less than 19th magnitude; we do use that catalog
for our field finding computers that drive the telescopes but the A2.0 catalog is
virtually obsolete and is error-ridden. For good astrometry or photometry, the newer
UCAC-4 catalog is the one of choice. Very few people are using the B1.0 catalog and
frankly it has far more errors than did A2.0; that catalog does list some stars to
near 20th magnitude, but not in all fields.

Clay
_____
Dr. P. Clay Sherrod
Arkansas Sky Observatories
MPC H45 - Petit Jean Mountain South
MPC H41 - Petit Jean Mountain
MPC H43 - Conway West
http://www.arksky.org/

----- Original Message -----
From: "tom" <loeblt@...>
To: <guide-user@yahoogroups.com>
Sent: Tuesday, April 02, 2013 5:57 PM
Subject: Re: [guide-user] Guide Question


> Hi,
> The Ucac4 and USNO A2 catalogs take me down to 19+ magnitude. My issue
> is that there are too many stars showing when I zoom out and I am trying
> to figure out how to control the rate at which the magnitudes (and hence
> the number of stars showing) decrease as I zoom out.
>
> Also I would like to understand in the Extras menu/Toggle User Data
> sets, how to fill in the individual catalog values for Limiting
> Magnitude, and especially the Show At option...
>
> Tom
>
> On 4/2/2013 6:42 PM, P. Clay Sherrod wrote:
>> I doubt that you are going to see any stars to 20th magnitude on Guide; the limit
>> is
>> imposed by the star catalog that you have defaulted to with the program and I am
>> not
>> aware of any star catalogs that are commonly used that go down that deep. The
>> sheer
>> size of such a catalog would be far beyond the capacity of your computer to hold
>> it.
>>
>> Dr. Clay
>> _____
>> Arkansas Sky Observatories
>> MPC H45 - Petit Jean Mountain South
>> MPC H41 - Petit Jean Mountain
>> MPC H43 - Conway West
>> http://www.arksky.org/
>>
>> ----- Original Message -----
>> From: "tom" <loeblt@...>
>> To: <guide-user@yahoogroups.com>
>> Sent: Tuesday, April 02, 2013 5:39 PM
>> Subject: [guide-user] Guide Question
>>
>>
>>> Hi,
>>>
>>> Normally, when I view the screen for my ccd size showing the ccd frame,
>>> I want to see 20th magnitude. As I zoom out there are fewer stars
>>> showing but presently there are still too many stars showing in the
>>> wider views. How do I change the rate at which the stars disappear as I
>>> zoom out without changing the zoomed-in values of 20th magnitude? I use
>>> the mouse wheel to zoom.
>>>
>>> Tom
>>>
>>>
>>>
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>>>
>>
>>
>>
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>>
>>
>
>
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