Hubble captures densely packed shimmering star field near the center of the Milky Way

Hubble Space Telescope image of a scintillating star field that contains the ESO 520-21 globular cluster (also known as Palomar 6). Credit: ESA / Hubble and NASA, R. Cohen

This sparkling star field, captured by the Nasa/THIS The Hubble Space Telescope‘s Wide Field Camera 3 and Advanced Camera for Surveys, contains the globular cluster THIS 520-21 (also known as Palomar 6). A densely packed, roughly spherical collection of stars, it sits near the center of the Milky Way, where interstellar gas and dust absorb starlight and make observations more difficult.

This absorption by interstellar matter affects certain wavelengths of light more than others, changing the colors of astronomical objects and making them appear redder than they actually are. Astronomers call this process “redness” and this makes it particularly difficult to determine the properties of globular clusters near the galactic center – such as ESO 520-21.

ESO 520-21 is located in the constellation Ophiuchus, near the celestial equator. Ophiuchus was one of the 48 constellations that appeared in the writings of the 2nd century Egyptian astronomer Ptolemy, all of which are among the 88 constellations officially recognized by the International Astronomical Union today. However, not all of the constellations proposed by astronomers throughout history have survived – forgotten or obsolete constellations include Felis (the cat), Rangifer (the reindeer) and even Officina Typographica (the printer’s workshop). .