The Brightest Deep Sky Objects in June 2023
In June, you can spend nights observing deep-sky objects, even with amateur optics. Deep-sky objects (or DSOs) are celestial bodies located outside our Solar System. The brightest of them are listed in the Messier Catalog. You’ll recognize a Messier object by the letter “M” in its name. The other popular reference list is The New General Catalogue of Nebulae and Clusters of Stars – its objects receive the letters “NGC.” Apart from these, there are other deep-sky catalogs, like the Index Catalogue, Caldwell, Collinder, Barnard, and others. Some DSOs are listed in multiple catalogs, so they have several different names.
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The brightest deep-sky objects tonight
In June 2023, we’ll have a great view of several globular and open star clusters:
- June 2: M13 (magnitude 5.8);
- June 3: M12 (magnitude 6.1);
- June 6: M10 (magnitude 6.6);
- June 7: M62 (magnitude 6.4);
- June 11: M92 (magnitude 6.5);
- June 16: NGC 6388 (magnitude 6.8);
- June 17: M6 (magnitude 4.2);
- June 17: NGC 6397 (magnitude 5.6);
- June 18: IC 4665 (magnitude 4.2);
- June 20: M7 (magnitude 3.3);
- June 23: M8 (magnitude 5.8);
- June 24: NGC 6541 (magnitude 6.6);
- June 29: NGC 6633 (magnitude 4.6).
You can easily locate DSOs with the Sky Tonight astronomy app. Use the search function to find the object you’re interested in, then tap the blue target button next to it. Point your device towards the sky, and follow the white arrow as it directs you to the object’s position in the sky above you.
But that's not all! Sky Tonight offers another exciting feature for observing DSOs. You have the ability to customize how these objects are displayed on your screen. Just go to the Menu, navigate to Settings, then tap Sky. From there, you can choose the DSO Visibility to suit your preferences: Basic, Advanced, or Pro. With the Basic mode, you will only see the most prominent DSOs; the Advanced and Pro modes will help you find even more deep-sky objects in the sky.
But now let’s take a closer look at the 7 brightest deep-sky objects, some of which can even be seen with the naked eye.
June 2: The Great Globular Cluster in Hercules (M13)
The Great Globular Cluster in Hercules (the Hercules Globular Cluster, Messier 13) will shine at a magnitude of 5.8, reaching its highest point in the sky at your local midnight. M13 is one of the brightest star clusters in the Northern Hemisphere, but it’s only seen from the latitudes north of 33°S.
The globular cluster got its name from the constellation Hercules, where it is placed. It contains several hundred thousand stars that are so close together that they sometimes collide and form new stars. M13 can’t be seen with the naked eye, but you’ll get a great view of the globular cluster even through a pair of binoculars or a small telescope.
June 17: The Butterfly Cluster (M6)
Look for the Butterfly open star cluster (Messier 6) in the constellation Scorpius, shining at a magnitude of 4.2. The observers in the Southern Hemisphere will get the best view, but you can’t see the cluster from latitudes much north of 37°N. In June, M6 will be visible all night long, reaching the highest point in the sky at around midnight local time.
M6 covers about as much of the sky as the Full Moon, so it’s better to observe it through a pair of binoculars or a small telescope because it won’t fit in the view of the larger optics. You’ll see the butterfly shape composed of blue stars and one outstanding orange star. You can even try to spot it with the naked eye – dark skies and sharp eyes provided.
From butterflies to dolphins and even skulls, deep-sky objects can take on all sorts of strange shapes. Take our quiz and see if you can guess the name of a nebula by looking at its photo!
June 17: NGC 6397
The globular cluster NGC 6397 is located in the constellation Ara. It is one of the closest globular clusters to the Earth, placed 7,800 light-years away from it. The best locations to observe NGC 6397 are in the Southern Hemisphere, in latitudes south of 16°N.
Shining at a magnitude of 5.7, the globular cluster will be tricky to spot with the naked eye, but you’ll see the bulk of stars through a pair of binoculars or a small telescope. Through a telescope, you'll see the myriad of blue, white, and orange stars of varying sizes.
June 18: IC 4665
The open star cluster IC 4665 will shine at a magnitude of 4.2 in the constellation Ophiuchus. It’s well seen both in the Northern and Southern Hemispheres, between the latitudes 75°N and 64°S. The best time to see the cluster is at around midnight local time.
IC 4665 may seem dimmer than its apparent magnitude because the cluster is spread out more than twice the Full Moon diameter. To get a better view, use a pair of binoculars or a small telescope. You can even try to spot IC 4665 with the naked eye from locations that aren’t light-polluted.
June 20: the Ptolemy Cluster (M7)
The Ptolemy Cluster (Messier 7) will shine brightly at a magnitude of 3.3 in the constellation Scorpius. It will be best seen in the Southern Hemisphere, from latitudes south of 35°N. The best time to observe the cluster is at around midnight local time.
As the cluster’s name suggests, M7 was discovered back in antiquity by Greek-Egyptian astronomer Claudius Ptolemy. He observed the cluster without any optics, and you can also try to spot the Ptolemy Cluster with the naked eye in the dark skies. You’ll get the best view of M7 with a pair of binoculars or a small telescope.
June 23: The Lagoon Nebula (M8)
The Lagoon Nebula (Messier 8) is a giant emission nebula, about three times the visual size of the Full Moon. It is located in the constellation Sagittarius. In June, M8 will shine at a magnitude of 5.8, best seen in the Southern Hemisphere from latitudes south of 45°N. It will reach its highest point in the sky at your local midnight.
The Lagoon Nebula is also home to a young open star cluster NGC 6530 (magnitude 4.6). You can try to spot both M8 and NGC 6530 with the naked eye in the dark skies without any light pollution, but it’s better to use at least a pair of binoculars. With an amateur telescope, you’ll get a great view of more than two dozen stars.
June 29: NGC 6633
The open star cluster NGC 6633 (magnitude 4.6) will shine brightly in the constellation Ophiuchus. The cluster will reach its highest point in the sky at around midnight local time. It will be well seen in the Northern and Southern Hemispheres, at latitudes between 76°N and 63°S.
NGC 6633 covers about as much of the sky as the Full Moon. Therefore, it’s best observed through a pair of binoculars. If you want to use a telescope, better to choose a smaller one so that the cluster entirely fits in the field of view. But you can even try to spot the cluster with the naked eye if your eyes are sharp and the skies aren’t light-polluted.
Deep-sky objects meet the Solar System objects
In June 2023, we’ll also enjoy DSOs meeting the objects in our Solar System. So let’s take a closer look at these events.
June 2: Mars meets the Beehive Cluster
On June 2 at 03:30 GMT (June 1, 11:30 p.m. EDT), Mars (magnitude 1.6) will pass within 0°6' of the Beehive Cluster (magnitude 3.1). At such a close distance, the objects will fit together in the field of view of a telescope, but they can also be seen with the naked eye or binoculars. As night falls, look for the objects in Cancer near the western horizon.
June 11: Mercury meets the Pleiades
On June 11, at 17:50 GMT (01:50 p.m. EDT), Mercury (magnitude -0.4) will pass 6°12' from the Pleiades (magnitude 1.2). Both objects will be located in the constellation Taurus near the eastern horizon. They will be bright enough to see with the naked eye, but you will only be able to observe them for about an hour before sunrise. If you are using optics, be careful not to point them at the Sun as it rises. It can cause permanent blindness.
June 13: Venus meets the Beehive Cluster
On June 13, at 11:05 GMT (07:05 a.m. EDT), Venus (magnitude -4.5) will pass 0°30' of the Beehive Cluster (magnitude 3.1). Look for the objects in the constellation Cancer near the western horizon after sunset. They won’t fit together in the field of view of a telescope, but you can see them through binoculars or even with the naked eye under the clear dark sky.
June 16: the Moon meets the Pleiades
On June 16, at 00:47 GMT (June 15, 08:47 p.m. EDT), the Moon (magnitude -7.2) will be 1.8° from the Pleiades (magnitude 1.2) in the constellation Taurus. However, the lunar disc will be only 5% illuminated and, therefore, almost invisible to the naked eye. Use binoculars to better see both objects in the sky. They will be visible on the eastern horizon for about an hour before sunrise.
June 21: the Moon meets the Beehive Cluster
On June 21, at 10:38 GMT 06:38 a.m. EDT), the 10% illuminated Moon will pass 4° of the Beehive Cluster (magnitude 3.1). You will be able to see the thin waxing crescent close to the bright cluster with the naked eye. The objects will be in the constellation Cancer on the western horizon. Look for them in the sky as soon as it gets dark.
Bottom line
June is a good month to observe deep-sky objects and how they meet the Solar System bodies in the sky. If you aren’t sure where and when to see deep-sky objects from your location, use the stargazing app Sky Tonight. You just need to type the name of the DSO you’re looking for (or its catalog designation) in the search bar, and you’ll learn about the object’s location, related events, and other detailed information.
We wish you clear skies and successful observations!
