[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Data Taking Plan for TOM2




  Tom wrote:

> I propose to point TOM2 at the pole and take data similar to the flat 
> runs.  I could take 30 or so exposures rotating around the pole. ...
> 
> The reason I propose this is that I assume that the pole has been well 
> studied, and that there will be lots of available calibration 
> stars.  Hmmmm! Does Landolt do the pole?

  No, there are no Landolt fields near the Pole.  That area
_was_ used as a standard calibration field in the "early days"
of photometry, from 1880 to about 1960, but it has fallen out
of favor lately.  There is quite a lot known about those stars; 
you can find some of it by going to the Astrophysics Data Service at

      http://adsabs.harvard.edu/abstract_service.html

and typing "North Polar Sequence" into the "title words" box.
You'll see, for example, that were several papers published
on the topic back in the 1940s and 1950s, but (as I mentioned),
not much lately.  The recent papers returned by this search
are about the geology around Mars' North Pole.

  Arne Henden's catalog of UBVRI measurements of stars,
available at 

      http://a188-l009.rit.edu/tass/catalogs/catalogs.html#ubvri

doesn't include any stars farther north than Dec = +77.  The LONEOS
catalog of stellar measurements 

      http://a188-l009.rit.edu/tass/catalogs/catalogs.html#loneos

includes some stars beyond Dec = +85, up to Dec = +88.7.  
Some of these would be in the field, especially
if you pointed the telescope so that the North Pole was at the 
"top" end of the frame, rather than centered in the middle.

  One point in favor of this plan: very few other astronomers
look at the area, so you'd be covering relatively virgin ground.

  Another point in its favor: the stars would always be at
(nearly) the same airmass, which eliminates one type of systematic
error in the reductions.  

                                          Michael Richmond