The bright planet Mercury passes the star Regulus in Leo just before sunrise — if you’re quick, you can spot them.
The heart of Leo the Lion, Regulus, lies to the lower right of Mercury in the morning sky just before sunrise. Credit: Stellarium
- At 6 A.M. EDT, Mercury will pass 1.2° north of Regulus, observable in the east before sunrise from locations with clear eastern horizons.
- Mercury, with a magnitude of –1.3, will reach an altitude of 4° approximately 30 minutes before sunrise, appearing to the lower left of Venus (magnitude not specified). Regulus (magnitude 1.4) will be located just over a degree to Mercury’s lower right and may require binoculars or a telescope for observation.
- Telescopic observation of Mercury will reveal its 5” apparent width, 90% illumination, and smaller size compared to Venus (85% illumination and larger disk size).
- Provided local sunrise, sunset, moonrise, moonset times, and moon phase (73% waxing gibbous) for 40° N 90° W, with the caveat that these times might differ slightly based on location. Observation with optical instruments should cease several minutes before sunrise.
Mercury passes 1.2° north of Regulus at 6 A.M. EDT; the pair is visible in the east just before sunrise, but it might be a challenging observation. You’ll want to get to a location above the surrounding terrain if possible, with an eastern horizon free of tall trees or buildings.
Rising around 5:30 A.M. local daylight time, Mercury reaches an altitude of 4° roughly half an hour before sunrise. It’s now magnitude –1.3, which should help it stand out against the brightening sky, although binoculars can also help you locate it to the far lower left of blazing Venus, which stands some 20° high at this time. Magnitude 1.4 Regulus will be more challenging and may only be visible with binoculars or a telescope, just over a degree to the lower right of Mercury in the sky as they are rising. The star should be just within the same field of view as the planet with a telescope, and definitely within a single binocular field.
If you’re using a telescope, take a moment to focus on Mercury as well. The tiny planet appears 5” wide — nearly 2.5 times smaller than Venus’ disk, currently — and is 90 percent lit, slightly more than Venus’ 85 percent. The latter, brighter planet hangs 2° directly below M44 this morning, so if you’d like to catch a binocular view of the two, you can look for them a little earlier, while the sky is still dark — try some 60 to 90 minutes before sunrise.
Note that you should always put away any binoculars or telescope at least a few minutes before sunrise occurs from your location, which may differ slightly from the times listed below.
Sunrise: 6:29 A.M.
Sunset: 7:30 P.M.
Moonrise: 4:44 P.M.
Moonset: 12:33 A.M.
Moon Phase: Waxing gibbous (73%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.
For a look ahead at more upcoming sky events, check out our full Sky This Week column.