I want to make some observations with a telescope in Hawaii on Mauna Kea but I am living somewhere else (not Hawaii) and I want to plan a night's viewing on the Hawaiian telescope. How do I find the RA range of the night? In other words; how do I find the RA range of the first object observable to the latest object observable for a particular time (of year) for a specific location (in this case Hawaii)?


Use Stellarium. You can set your location and date as needed and simulate all the conditions (ignoring weather...) :)



There is a very nice web-based utility called Staralt that I frequently use before observing runs.

This has lots of observatories pre-programmed or you can put in your own latitude and longitude AND altitude (can you do that in Stellarium?).

To quote the website - "you can plot altitude against time for a particular night (Staralt), or plot the path of your objects across the sky for a particular night (Startrack), or plot how altitude changes over a year (Starobs), or get a table with the best observing date for each object (Starmult).".

You can also do handy thing like produce plots, charts and tables or show where the moon is with respect to your targets.

  • $\begingroup$ Yes, you can enter a location's altitude in stellarium. Later versions of stellarium even have refraction. xephem (and ephem, the text version) can solve the problem as well. $\endgroup$ – barrycarter Oct 5 '14 at 16:55

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