The Regulus system as a whole is the twenty-first
brightest star in the night sky with an
apparent magnitude of +1.35. The light output is dominated by Regulus A. Regulus B, if seen in isolation, would be a binocular object of magnitude +8.1, and its companion, Regulus C, the faintest of the three stars that has been directly observed, would require a substantial telescope to be seen, at magnitude +13.5. Regulus A is itself a spectroscopic binary; the secondary star has not yet been directly observed as it is much fainter than the primary. The BC pair lies at an angular distance of 177 arc-seconds from Regulus A, making them visible in amateur telescopes. Regulus is 0.465 degrees from the
ecliptic, the closest of the bright stars, and is often
occulted by the
Moon. This occurs in spates every 9.3 years, due to
lunar precession. The last spate was in 2026, each one limited to certain areas on Earth. .|alt=|left Occultations by
Mercury and
Venus are possible but rare, as are occultations by
asteroids. Seven other stars which have a
Bayer designation are less than 0.9° from the ecliptic -- the next brightest of these is
δ (Delta) Geminorum, of magnitude +3.53. The last occultation of Regulus by a planet was on July 7, 1959, by Venus. The next will occur on October 1, 2044, also by Venus. Other planets will not occult Regulus over the next few millennia because of their
node positions. An occultation of Regulus by the asteroid
166 Rhodope was filmed in Italy on October 19, 2005. Differential bending of light was measured to be consistent with
general relativity. Regulus was occulted by the asteroid
163 Erigone in the early morning of March 20, 2014. The center of the shadow path passed through
New York and
eastern Ontario, but no one is known to have seen it, due to cloud cover. The International Occultation Timing Association recorded no observations at all. Although best seen in the evening in the northern hemisphere's late winter and spring, Regulus appears at some time of night throughout the year except for about a month (depending on ability to compensate for the Sun's glare, ideally done so in twilight) on either side of August 22–24, when the Sun is too close. The star can be viewed the whole night, crossing the sky, in late February. Regulus passes through
SOHO's
LASCO C3 every August. For Earth observers, the
heliacal rising (pre-sunrise appearance) of Regulus occurs late in the first week of September, or in the second week. Every 8 years,
Venus passes very near the star system around or a few days before the heliacal rising, as on 5 September 2022 (the superior conjunction of Venus happens about two days earlier with each turn of its 8-year cycle, so as this cycle continues Venus will more definitely pass Regulus
before the star's heliacal rising). ==Stellar system==