Challenge #1 – M64

TargetTypeR. A.Dec.ConstellationMagnitudeSize
M53 (NGC 5024)Globular Cluster13h 12m 55s+18° 10′ 05″Coma Berenices7.613.0 arcmins


This globular cluster is easily accessible in small telescopes and binoculars. Its brightness comes from the 220 light-years wide grouping of stars that shine with the brightness of 200,000 suns.

Remarkably, this is one of the most distant globulars within the Milky Way, lying about 60,000 light-years from us. Imagine how bright it would be if it were only 20,000 light-years away!

Johann Elert Bode discovered this cluster in February 1775. Two years later, Messier discovered it independently and added it to his famous catalog.

The cluster is 12.7 million years old and a lovely discovery for us to enjoy.

M53 (NGC 5024), a bright planetary globular cluster in Coma Berenices (source)

Finder Charts

This first sky chart, from SkySafari 6, shows the sky looking east at 11 pm in the middle of February. Our cluster is about a third of the way towards overhead from the eastern horizon. Orientate yourself to find Arcturus, the brightest star in Boötes, and Denebola in Leo. Both are shown in more detail in the next chart.

Stars on this chart are shown to magnitude 5.0 and the moon and planets are not shown.

[M64-1] Our hunt begins looking east around 11pm in mid-february. Click for full-screen.

Use the bright stars Denebola in Leo and Arcturus in Boötes to locate the magnitude 4.3 star called Diadem in Coma Berenices. This star is so close to the cluster that it’s a simple task to locate it from there.

[M64-2] We need to locate the magnitude 4.3 star Diadem. Click for full-screen.

Stars are shown to magnitude 9.0 and you can see how close the M58 cluster is to the star Diadem. In fact, a one degree field of view (shown by the blue circle) will just about contain both objects.

[M64-3] The cluster is almost exactly one degree northeast of Diadem. Click for full-screen or download the pdf below.

Now you have this cluster in your eyepiece, what should you expect to see?

Individual Telescope Views

The following views will help you find M53 in different telescope types by presenting the images as your telescope will show them. The first image is with a black sky and white stars, the second picture is the same image but presented in inverse monochrome. Black stars on a white background is often easier to use at the telescope. Stars are shown to magnitude 15.0 and the circle is a 1° field of view. Each image can be clicked on for a full-screen version.

Upright View – This is what your eyes see unaided and through a reflex or red-dot finderscope


Upside-down view – This is what reflectors and magnifying finders show, and refractors / Cassegrains without a star diagonal


Mirrored View – Refractors and Cassegrain models with a star diagonal show this view



In binoculars, M53 appears as a tight, fuzzy glow with near-uniform brightness but a noticeable dimming towards the outer rim.

Mid-sized telescopes reveal some structure at medium magnifications but, if the seeing is good enough, higher magnification will tease out individual stars.

Given its brightness and proximity to Alpha Coma Berenices (Diadem) this is an easy cluster for us to pick out. Try to wring out of it the shapes and patterns caused by streams of stars and don’t forget to use averted vision to enhance your viewing.

PDFs for Printing

Each of the star maps above is reproduced as a pdf below. Each star map has a number in [square brackets] beneath it which corresponds to the file number below. If you want image [M64-1], for example, click the ‘download’ button next to it below and you’ll be able to open it as a printable pdf.