On Sunday evening, March 29, 2026, residents of the southwestern regions of Russia will be able to observe the Moon covering the brightest star in the constellation Leo, Regulus. This was reported to RIA Novosti by Crimean astronomer Alexander Yakushechkin. The phenomenon is available for observation in Crimea and in the south of the European part of the country. It will begin at 22:00 Moscow time (for the longitude of Simferopol): the star will first be covered by the unlit part of the lunar disk, at 22:04 the Moon will completely absorb Regulus, and at 23:00 the star will reappear near the lunar north pole above the Sea of Humboldt. The Moon is in a phase close to full moon (full moon is April 2), so the disk will be bright, but the coverage will occur from the shadow side, which will facilitate observation.
Regulus: A Quadruple Star in the Constellation LEO
Regulus (α Leo) is one of the brightest stars in the night sky, its name comes from the Latin "prince." It is not a single star, but a system of four luminaries, united in two pairs. The main component is Regulus A, a blue star whose mass is 3.5 times greater than the Sun's. In 2008, a dwarf companion star, Regulus D, was discovered next to it, so close that the main star is pulling hydrogen from its envelope. This allowed astrophysicists to revise the age of the system: it was originally assumed that Regulus A was about 100 million years old, but taking into account the "cannibalism," its age may reach 700–900 million years.
Every nine years, there is a period of 1.5 years when, for us earthlings, the Moon, in its movement, covers Regulus. The current series began on June 26 and will last until January 24, 2027. The next series of Regulus coverings will be from 2035 to 2036.
How to Observe the Phenomenon
For successful observation, a clear sky in the southwest is required. The Moon will be almost full, but Regulus will disappear behind the dark edge of the disk, which makes the phenomenon contrasting. It is best to use binoculars or a small telescope to see the moment the star "touches" the lunar limb.
Coverings of bright stars by the Moon help to refine the parameters of the lunar orbit and study the structure of stellar systems. For Regulus—a multiple system with mass transfer—each covering provides data on the brightness distribution in the close pair. The current series will last until January 2027, the next one will occur in nine years.
For residents of Crimea and southern Russia, the phenomenon will be clearly visible to the naked eye. The coverage time (22:00–23:00 Moscow time) is convenient for evening observations. Astronomers recommend choosing places with an open southwestern horizon.