#Observation planner readme#

The observation planner was made to help with choosing objects to observe at the old observatory. Suggestions for improvements and questions can be emailed to me: sanderschouws@gmail.com



# Used Catalogs
The data on the planets are taken from pyephem. All planets and pluto are available. No information is available on other lare objects like Vesta or comets, but this could be added in the future.

For the NGC-IC objects, the "Revised New General Catalogue and Index Catalogue" is used (source: http://www.klima-luft.de/steinicke/). This should be a reasonably accurate catalog concering these objects.



# Time
Local time is used unless stated otherwise. It is assumed that the observations take place between sunset (or 17:00) and midnight (24:00). Time dependent variables are calculated at the mean of this observing time.



#Source selection
For a source to be selected as observable a number of criteria are important:
1. The source should be 30 degrees above the horizon for at least 50% of the observing time. For planets a limit of 20 degrees is used.
2. Objects should be brighter than 10 maginutdes in V band, though planets are not subject to this magnitude limit (planet magnitudes are estimated by pyephem). (At the moment NaN values are also selected, many sources do not have a valid V band magnitude in the catalog).
3. Deep sky objects should be either galaxies or nebulae. Globular and open clusters are excluded as they are numerous adn rather boring.



#Images layout
The images are sorted by NCG number. The top left figure of the images is an airmass plot for the object in question. The moon is shown with a dashed gray line. The black vertical lines indicate the observing time and the red vertical lines the start and end of astronomical twilight. The plot starts half an hour before sunset and ends half an hour after sunset. The time axis shows the local time.

The top right figure displays some relevant information. Here, time dependent variables are calculated for the mean of the observing time, i.e. the middle of the start and end of observing. All physical parameters are taken from the catalog for deep sky objects.

Some terms might be confusing and will be outlined here:
* SB:   Surface brightness in mag/arcmin^2
* z:    Catalog redshift
* Alt.: Alternative names (look here for Messier objects)
* LST: 	Sidereal time with mean observing time in brackets
* Twi.: Astronomical twilight start and end
* Ill.: Moon illumination
* Sep.: Seperation between moon and object of interest

The lower left figure shows a 2x2 deg DSS cutout to help with finding the object. The lower right figure shows a more detailed 0.5x0.5 deg DSS cutout, this should be similar to the field of view from the student telescope.

The DSS survey has a magnitude limit of ~22 (varies) (Digitized Kodak 103a E-plate (red sensitive)) and a resolution of ~2 arcsec. The depth is similar as a 600 second exposure of the student telescope and a googolplex second exposure with the 10" telescope.

(In the future maybe some better advice on the exposure times could be added, but to produce this emperical data will be needed.)