The Rho Ophiuchi complex, a large stellar nursery in the constellation Ophiuchus, the Serpent Bearer, as viewed by ESA's Gaia satellite after its first 14 months of operations. These views are not photographs but were compiled by mapping the total density of stars (left) and the total amount of radiation, or flux (right), detected by Gaia in each pixel.
On the left, the image based on the stellar density shows the distribution of all stars in the area, and clearly outlines the silhouette of dark clouds of gas and dust hiding background stars from view. On the right, the image based on the total flux is dominated by the brightest, most massive stars; in some spots, these stars outshine their less bright, lower-mass counterparts.
Five bright stellar clusters stand out in both views: the brightest one, towards the right of the frame, is the globular cluster M4.
This image was produced by André Moitinho, Márcia Barros, Carlos Barata from the University of Lisbon, Portugal, and Hélder Savietto from Fork Research, Portugal. The creation of this and other similar images is described in the paper "Gaia Data Release 1: The archive visualisation service" by A. Moitinho et al. 2017, A&A, 605, A52.