This tool plots the airmass (and altitude values) of an object given its RA and Dec for any given date. See a demo here. Additional features include:
- Plot of Moon altitude and percent illumination values
- Civil, nautical and astronomical twilight zones are shown by three color bands
- Set of predefined observatory sites for easy selection are provided.
- User can also input a user defined site information, i.e, lat-long and time-zone
- Date input also accepts text like 'Today', 'Tomorrow', 'Yesterday', 'Next week', 'Last week', 'Last month' etc. This way you can have a plot-link, whenever you open, it will plot for the given time offset, instead of a fixed date.
- You may embed these plots or link in your website to dynamically generate these plots by changing the parameters in URL.
You may either use the tool from below or open in an external window, from there you can share or save your plot configuration using the address bar URL.
All visibility calculation are done from scratch without using any third-party library. Although it has been extensively used internally and debugged before making it public, please let me know if you find any incorrect result.