Regardless of brightness or size, globular cluster m70 looks similar to its neighbor m69. In fact, it is only a little brighter, a little larger, and almost at the same distance (29300 light-years).
Both are quite closethe galaxyTherefore, they are subject to quite strong gravitational tidal effect.As it is also located in the south of the celestial sphere, it is a difficult object to observe for the observation site of Messier, Paris.
messier Found this on August 31, 1780Globular clusterAnd described it as a "nebula without stars".William Herschel first decomposed the globular cluster into stars, describing it as a "m3 miniature model".
The angular diameter of m70 is 8.0 angular minutes, the true size is about 68 light-years, and the visible bright core is only about 4 '.It is moving away from us at a speed of about 200 km/s.There are only two known variable stars in this cluster.
The core of m70 is extremely dense because it has experienced core collapse in history.In 150 known galaxiesGlobular clusterAt least 21 and perhaps as many as 29 globular clusters are similar to m70 and have experienced core collapse, including m15, m30 and possibly m62.
In 1995, globular cluster m70 became famousComet Hale BoppIt was discovered near it. At that time, the discoverers alan hale and thomas bopp were observing this globular cluster.[1]
