Re: Is there some website that will allow me to plot star maps with labelled magnitudes?

On Sep 19, 11:52 am, alliso...@xxxxxxxxxxx wrote:
I am interested in observing some of the many Hamburg Quasar Survey
cataclysmic variables for which no AAVSO chart (or any other, as best
as I can tell) has been created. Is there some place on the internet
where I can create such charts? I would need a limiting magnitude down
to about 15.0 or so.

Normally, this is done with a generic laptop planetarium program that
has the LEONES and abbreviated USNO B2.0 catalogues installed, or with
speciality photometry software like MPO Canopus. The reduced USNO
catalogue (on three CDs) generally has to be obtained through an
advanced imaging amateur in your local club. Alternatively, follow
the AAVSO yahoo newsgroup. Typically for breaking news objects, a
quick photometry list will be posted by a member of the AAVSO
newsgroup list.

Using Simbad's Aladin applet, you can generate an image and table of
stars in a selected region, but not an image over-plotted with
magnitudes.

http://simbad.u-strasbg.fr/simbad/sim-fid

Enter the object name or coordinates in the Simbad query screen.

V* V455 And
23 34 01.55 +39 21 42.9

When the object information is displayed, load the full Aladin Java
Applet. If the applet cannot find the object name, there is an box to
paste in the coordinates - see the "Position" box. For V455 And, you
will have to paste in the coordinates.

Once the Aladin image and object map layer displays, simply left-click
drag a box region around the object of interest. In the lower table
box, the applet will display red, green and blue photometry
information on all the objects in the selected region.

The "Save" button exports a fits image of the display and a text table
of all the objects in the region of interest in the display.

The number of objects in the display can be narrowed considerably to
the relevant magnitude by first applying a magnitude filter. The
option sequence - "filter" button, "advanced filter" option,
"predefined filters" pull down, and "magnitude cut" - will allow you
to set a magnitude cut limit of 13 to 15 mags in the red band.

If you do not get enough stars using a mag 13 cut-off, use the 1/4
Zoom option to get a bigger field of view.

To generate a clean display it may be necessary to delete old
magnitude cut layers. Right click a layer on the right-hand side of
the Aladin display. Select "delete" to remove it.

The filter button options also appears to have a facility to plot
magnitudes next to the reduced set of stars on the image. I have not
been able to make that option work.

The AAVSO also has a beta test chart generator. It produces the
charts using coordinates, but I have not been able to get it to
produce a photometry table of stars.

http://www.aavso.org/observing/charts/vsp/

- Canopus56



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