Distance, Size, and Mass. Regulus (reg -yŭ-lŭs) (α Leo) A bluish-white star that is the brightest one in the constellation Leo and lies at the base of the Sickle of Leo. The Moon makes a complete orbit around the Earth in 27 Earth days. However, Regulus’ heliacal rising, which is when the star becomes visible in the east for a short while just before sunrise, occurs in the first week of September each year, and is visible to most observers on Earth. This star is at a much greater distance from Earth: 1700 light-years. Regulus or Alpha Leonis (Alp Leo) is the brightest naked eye star in the constellation Leo.With an apparent magnitude of 1.36, Regulus is the 21st brightest star in the entire sky (see: 50 Brightest Stars ).Its absolute magnitude is -0.52 and its distance is 78 light years.The Equinox J2000 equatorial coordinates are RA = 10h 08m 22.3s, Dec = +11° 58' 02". The absolute magnitude is the magnitude the stars would have if viewed from a distance of 10 parsecs or some 32.6 light years.

Star System. Eta Leonis, north from Regulus, looks weak, but it spreads a hundred times as much light as Regulus. In fact, if Regulus were spinning only 15% faster, it would tear itself apart. The primary star Regulus A has 3.8 solar masses and a radius of around 3.9 solar radii. The cause of Regulus… Obviously, Deneb is intrinsically very bright to make this list from its greater distance.

of 1.35 makes it one of the 25 brightest stars in the sky. The distance from Earth to the sun is called an astronomical unit, or AU, which is used to measure distances throughout the solar system. While real stars distances are highly accurate as they are based on the newest data available (from the 1990s HIPPARCOS satellite survey), somehow even revising older information (e.g. The shape and size of Regulus compared to the Sun (smaller yellow circle). This jibes well with the dialogue evidence: Regulus is said to be about three hundred lightyears from Bajor, and lies about 80 lightyears to the "lower right" of Earth in reality. Regulus (Alpha Leonis) is the brightest star in the constellation Leo and the 21st brightest star in the sky as seen from Earth. Jupiter , for example, is …

Combining these, we get a relatively short distance between Bajor and Earth, in the 50-200 ly ballpark.

For some decades, the most important distance measurement for Deneb is that from ESA’s Earth-orbiting Hipparcos satellite, which operated from 1989 to 1993. The brightest is Regulus (='Little King') at 85 light-years from Earth, the second brightest Denebola at 42 light-years. The Moon is Earth’s satellite and orbits the Earth at a distance of about 384,000 km or 239,000 miles. Its distance from the earth is about 85 light-years. The primary pair, Regulus A and Regulus B are separated by a distance of around 0.40 AU.