🔭Astro Transit
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🔭 Astro Transit

Pick a galaxy, nebula or cluster to find the date it transits around midnight at your site — the best season to image it.

Find the date an object transits at midnight

The remaining 3,786 IC objects (small galaxies, etc.), 1,779 Lynds dark nebulae (LDN), 313 Sharpless objects (Sh2) and 72 Abell planetary nebulae appear as you type a name above (e.g. IC1805, LDN1622, Sh2-155, Abell21). To browse them, see the IC, LDN, Sh2 and Abell lists.

Observing site (Tokyo if not specified)

Enter latitude and longitude, and choose the time zone of the observing site (your browser's time zone is added to the list).

Choose from locations saved in this browser.

Save the current lat/lon as a location

Get your current latitude and longitude from the browser.

Click the map or drag the pin (online only).

✨ What transits tonight?

Choose a date and location to get imaging targets (galaxies, nebulae, clusters) that transit around midnight that night.

See tonight's picks →

About this site

Using the coordinates of 8,802 objects — the 110 Messier and 109 Caldwell objects, 2633 NGC/IC objects of 2.0′ or larger (all planetary nebulae regardless of size; duplicates of Messier/Caldwell excluded), the remaining 3,786 IC objects (small galaxies, etc.), 1,779 Lynds dark nebulae (LDN), 313 Sharpless objects (Sh2) and 72 Abell planetary nebulae — the transit date is calculated from sidereal time (an approximate polynomial for Greenwich mean sidereal time). An object transits when it crosses the meridian (due south). The closer its transit is to midnight, the longer it stays high through the night, which makes that season the best time to observe and image it.

NGC/IC data comes from the OpenNGC project (mattiaverga/OpenNGC, CC BY-SA 4.0). LDN dark nebulae come from the Lynds (1962) catalog (VizieR VII/7A, CDS Strasbourg); their size is shown as the diameter of a circle of equal area. Sharpless objects come from the Sharpless (1959) catalog (VizieR VII/20; positions converted from equinox 1900), and Abell planetary nebulae from the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (VizieR V/84; confirmed planetary nebulae with a known diameter only).

Browse the object catalog →