A new record for the most distant galaxy cluster has been set using NASA’s Chandra X-ray Observatory and other telescopes. CL J1001+0220 is located about 11.1 billion light-years from Earth. The discovery of this object pushes back the formation time of galaxy clusters — the largest structures in the universe held together by gravity — by about 700 million years.
A scholarly investigation of the Cairo Calendar papyrus (1244–1163 B.C.) has led researchers at the University of Helsinki to conclude that the ancient Egyptians were aware that the variable star Algol (beta Persei) had a 2.85-day period. Given that the star’s current period is 2.8673 days, this supports the theory that mass transfer between the stars of this eclipsing binary has caused a long-term increase of its orbital period.