An article published in the journal “The Monthly Notices of the Royal Astronomical Society” reports a solution to an astronomical mystery involving two galaxies that appeared to be mirror images of each other and turned out to be two images of the same galaxy doubled by a gravitational lens. A team of researchers led by Richard Griffiths of the University of Hawaii at Hilo used observations made with the Hubble Space Telescope to obtain enough information to understand the nature of what was named Hamilton’s Object because it was discovered by astronomer Timothy Hamilton. Meanwhile, a third image of the galaxy was discovered, visible in another area of ​​the sky again thanks to the gravitational lens.

An article published in “The Astrophysical Journal Letters” reports a precise measurement of the distance of the galaxy NGC1052-DF2 that was used to confirm that it’s almost devoid of dark matter, a notable anomaly. A team of researchers led by Pieter van Dokkum of Yale University used the Hubble Space Telescope to observe the red giants on the outskirts of NGC1052-DF2 using them as “standard candles” taking advantage of the fact that they all reach the same peak in brightness. Understanding why so few of the gravitational effects attributed to dark matter are detected in this galaxy may offer new clues to its nature.