Photo by Pittendreigh
HOW TO FIND IT WITHOUT A COMPUTER:
Just find Antares, the brightest star in Scorpius, and look toward the head of the scorpion and you should easily see M4.
WHAT TO LOOK FOR:
M4 is rather large, but rather dim, and may give some the impression of an rich, open cluster.
Most globulars look about the same, but M4 should have a distinctive appearance. Look for a loosely packed globular with a straight line of stars across its disk. This line of stars makes M4 quite different from other globulars. The cluster is irregular disk. The core is elongated and the rest of the disk has an irregular shape with clumps and chains of stars across the disk. Binoculars show this cluster in its true beauty.
M4 was discovered by de Cheseaux in 1746. It is 6500 light years distant and as such it is believed to be the closest globular cluster to Earth. Only NGC6397 in Ara and NGC6366 in Ophiuchus are possibly closer. This Globular Cluster is below average in luminosity, with the luminosity of 44,000 sun.
HOW TO FIND IT WITHOUT A COMPUTER:
Just find Antares, the brightest star in Scorpius, and look toward the head of the scorpion and you should easily see M4.
WHAT TO LOOK FOR:
M4 is rather large, but rather dim, and may give some the impression of an rich, open cluster.
Most globulars look about the same, but M4 should have a distinctive appearance. Look for a loosely packed globular with a straight line of stars across its disk. This line of stars makes M4 quite different from other globulars. The cluster is irregular disk. The core is elongated and the rest of the disk has an irregular shape with clumps and chains of stars across the disk. Binoculars show this cluster in its true beauty.
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