The Night Sky

Find the Messier and Caldwell objects in the night sky at your observatory, as well as a few distinctive variable stars and transient events. The NGC and IC catalogs may be searched selectively by entering a specific name below, or by entering a partial name to limit the size of the search. Try something like "NGC 2" which would search everything staring with that from NGC 2 to NGC 2999 since long NGC searches will timeout.


Choose an observatory, or choose "manual coordinate entry" at end of list:

  Use UTC  /  Use observatory's local time.

Date window:

Base date for target list (mm-dd-yyyy or 'today'):

From that date, show targets for the next days.
(Also include targets from the previous days.)


Only show targets with an elevation (in degrees) of at least:

at event beginning:     Combine constraints with AND OR.
at event end:

Unspecified elevation constraints default to 0. Constraints are evaluated at night, i.e. to be shown as observable an event has to meet that elevation constraint during nighttime hours.

Ignore all elevation and day/night constraints; show all targets. Useful for space-based observing (but can generate lots of output if no target constraints specified).

Only show events with a depth of at least millimag.

Target list:

Select the catalog to use for the search:
Caldwell catalog, Messier catalog, and interesting stars
NGC and IC catalogs
Other transient objects

Mulitple objects
Only show object names matching this string ( not case sensitive ):
Single object with ephemeris below (above filters still apply, except depth filters).

RA (J2000):  
Dec (J2000):  
JD (UTC) of mid-event:  
Period (days):  
Event duration (hours):  
Target name (for labeling only):  

Show the input ephemeris data used to generate the target list:

Output format and labeling:

Output results as:
HTML table
CSV file for parsing by script.
CSV file for calendar import. (Save resulting output to a text file, then import into your observing calendar, e.g., import into Google Calendar.)

Day/night definition: start night at Sun altitude of  
The above choice determines both which events are displayed (since part of the event must be at night), and which parts of an event are color-coded to indicate daytime.

Maximum airmass to show in airmass plots:  
(Current airmass value of 2.4 is elevation of 24.6 degrees.)

The Caldwell list is from Observing the Caldwell Objects by David Ratledge (Springer, London, 2000).
The Messier list is based on the Wikipedia entry as of March 12, 2017.
The NGC catalog is from NGC 2000.0 by Rinnot (Sky Publishing, Cambridge, MA, 1988) provided through the CDS Viziers service.

The software producing this page is based on Tapir, created by Eric Jensen.

Last update: March 16, 2017
kielkopf at louisville dot edu