Two spectacular star clusters glitter close to the “stinger stars” – Shaula and Lesath – within the constellation Scorpius the Scorpion. Messier 6 and Messier 7 – or M6 and M7 – are open star clusters. Every cluster is a gaggle of stars shaped from the identical interstellar cloud. The 2 clusters are seen on summer time evenings within the Northern Hemisphere, or winter evenings within the Southern Hemisphere. They’re finest seen in a dark sky, and are a surprising sight by way of binoculars.
The right way to discover M6 and M7
These two star clusters are simple to identify in a darkish sky close to the curved tail of the constellation Scorpius the Scorpion. Scorpius is formed just like the letter J. The 2 stars, Shaula and Lesath – on the finish of the curved a part of the J – mark the tip of the Scorpion’s Tail. They’re referred to as the Cat’s Eyes, or the stinger of Scorpius. If you happen to draw an imaginary line from Lesath by way of Shaula, you’ll discover M7, which is the brighter and bigger of the 2 star clusters. Then from M7, you discover M6 solely a brief hop away.
Though M6 and M7 are seen to the unaided eye on a darkish, moonless night time, the brilliance and wonder of those deep sky objects are magnificent by way of binoculars. Plus you’ll be able to’t miss them, when you have a darkish sky.
If you happen to’re within the northern U.S., Canada, or an analogous latitude, you’ll want an unobstructed horizon towards the south to search out M6 and M7. They’re highest within the sky when due south, and even then by no means climb very excessive within the sky. In the meantime, from latitudes like these within the southern U.S., the clusters are simple to identify when highest within the south, above the Scorpion’s Tail. Typically, Scorpius is far simpler to view from the equator and many of the Southern Hemisphere.
Finest time to view
Consequently, in mid-June, these clusters bedeck the sky round midnight (1 a.m. daylight saving time within the U.S.). Remember that all the celebrities (and star clusters) return to the identical place within the sky some 4 minutes earlier with every passing day, or two hours earlier with every passing month. Subsequently, M6 and M7 seem highest within the sky at about 10 p.m. (11 p.m. daylight saving time) in mid-July, and eight p.m. (9 p.m. daylight saving time) in mid-August.
M6 and M7 science
Although M6 (Butterfly Cluster) and M7 (Ptolemy’s Cluster) seem shut collectively on the sky’s dome, they’re far aside in space. M6 is about 1,600 light-years away and shines at magnitude 4.2. M7 is about 980 light-years and shines at magnitude 3.3. So, the clusters are usually not associated to one another, however solely seem close to one another alongside our line of sight.
However, inside every cluster, the celebrities are associated. Every cluster was born from a single interstellar cloud of fuel and dust. The a whole bunch of stars in every cluster are certainly sibling stars, in that they’re gravitationally sure to 1 one other and journey in the identical course by way of space. Subsequently, astronomers name such a group of stars an open star cluster.
The clusters are within the thick of the Milky Way
M6 and M7 reside close to the galactic equator, the area on the sky’s dome wealthy with star clusters, star clouds, and nebulae. As soon as you discover M6 and M7, attempt finding different deep-sky binocular doubles, similar to M8 and M20. Additionally try M16 and M17. These deep-sky wonders loom farther away. Additionally, M6 and M7 are open star clusters. However M8 and M20, and M16 and M17, are nebulae the place stars are forming.
Backside line: Messier 6 and Messier 7 are placing star clusters close to the tail of Scorpius. M6 and M7 are finest in darkish sky situations by way of binoculars.
