This post is my view of the best 750 DSOs to be seen and imaged in the night sky from the northern hemisphere.  The purpose of this post is to provide a simplified tool to help the astrophotographer easily find targets on any night of the year.  

All of the images shown here were obtained from my temporary backyard setup in Onalaska, Texas at a declination of 31 degrees.  Locations further north will not be able to reach the southernmost objects shown here. 

The first 30 Revisions each are a poster of 25 DSOs, in order of Right Ascension.  The last 25 Revisions contain 19 pieces of object data for each of the 750 DSOs, including object description, magnitude, distance and size . 

A better resource for this information is the 16MB 86 page  pdf, available for free download at this link.  The pdf has additional information including active links taking you to Astrobin, SIMBAD and Aladin images of each object.

This collection of 750 DSOs has been assembled by including all of the objects from these 7 DSO catalogs:
1.    The catalog of 110 Messier (M) objects, established in the 1700s by Charles Messier.
2.    The catalog of 109 Caldwell (C) objects, published in 1995 by Patrick Moore.
3.    The catalog of 109 Hidden Treasures (HT) objects, published in 2007 by Stephen James O’Meara.
4.    The catalog of 109 Secret Deep (SD) objects, published in 2011 by Stephen James O’Meara.
5.    The catalog of 109 Orphaned Beauties (OB) objects, compiled by myself in 2020, comprised primarily of large narrowband objects.
6.    The catalog of 109 Small Packages (SP) objects, compiled by myself in 2020, comprised of small DSOs (<4 arc-minutes in diameter) best imaged with long focal length scopes.
7.    The catalog of 109 Faint Giants (FG) objects, compiled by myself in 2024, comprised of large faint DSOs best imaged with fast scopes.

The first 4 catalogues were developed primarily for visual use, while the last 3 were developed primarily for astrophotography.  The links above take you to my Astrobin compilation posters for each catalog, along with an Astrobin image and description post for each object.

All of the above catalog objects are unique – each DSO only appears one time, making for 764 total objects.  I have only included objects which I could image from my backyard, which excludes southern hemisphere objects at about -50 degrees declination and below.  I have also excluded most stars (except Messier objects) and quasars, bringing the total number from the above 7 catalogs to 732.  I then included 18 additional deserving objects, the Best of the Rest (BR) mini-catalog, to bring the total number of objects to 750 for this pdf.

On each of the 750 DSO poster images is 8 pieces of information.  A red font is used for object data with challenging declination, size or magnitude values:

1.    Object Type (29 DSO types included, as described in the pdf)
2.    Top 750 Number
3.    Designation 
4.    Catalog (out of the 8 described above)
5.    Declination in degrees (red if < -25°)
6.    Size in arc-minutes (red if < 4’)
7.    Rating (from 1 to 5)
8.    Magnitude (red if dim)  

Example:


Three pieces of data are shown in the left column of each poster row.  These data correspond to the left-most image of the row but will be similar for all objects in that row:
1.    The blue text shows the date on which the object transits overhead at 9 p.m. Standard Time (10 p.m. Daylight Savings Time).
2.     The green text shows the date on which the object transits overhead at 1 a.m. Standard Time (2 a.m. Daylight Savings Time).
3.    The orange text is the Right Ascension (RA) coordinates in hours and minutes.  

Example:

Scroll through the posters and use the above information to find appropriate targets for your setup.  For example, the Orion Nebula (M42 / #86) shown above will transit the meridian at 9 p.m. on Feb 4.  It has a RA value of 5 hr 35 min.  If instead you want to image the Rosette Nebula (NGC 2237 / #121) on Feb 4, which has a RA of 6 hr 31 min, it will be 56 minutes (the difference in RA) east of the Meridian at 9 p.m.    Likewise, the Witchhead Nebula (IC 2118, #66), which has a RA of 5 hr 5 min, will be 30 minutes west of the Meridian at 9 p.m.  

As a reminder, as the evening progresses and objects move across the sky from east to west, the Right Ascension value for any fixed point in the sky will continually increase until it reaches 24 hours and then resets back to zero to start increasing again. 

Please comment below with any questions or suggestions.  Which favorite target of yours have I left out?

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For a more comprehensive astrophotography targeting tool, please see my Excel-based Imm Deep Sky Compendium, published in 7 languages, covering 3100 objects, and providing exact targeting guidance based on the time and the user’s location.