The Moon in conjunction with Venus and Jupiter, with the Very Large Telescope in the foreground. Image © Y. Beletsky, ESO, 2009.

Lunar occultation of Regulus

Dominic Ford, Editor
From the Lunar Occultations feed

Objects: Regulus
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The Moon will pass in front of Regulus (Alpha Leonis), creating a lunar occultation visible from the Americas. Although the occultation will only be visible across part of the world – because the Moon is so close to the Earth that its position in the sky varies by as much as two degrees across the world – a close conjunction between the pair will be more widely visible.

The occultation will be visible from South El Monte. It will begin with the disappearance of Regulus (Alpha Leonis) behind the Moon at 17:13 PDT, though in daylight. Its reappearance will be visible at 18:34 PDT, though in daylight.

Extreme caution is necessary when pointing binoculars or telescopes at the sky when the Sun is above the horizon, as even a momentary glance at the Sun through such an instrument can cause permanent blindness.

The map below shows the visibility of the occultation across the world. Separate contours show where the disappearance of Regulus (Alpha Leonis) is visible (shown in red), and where its reappearance is visible (shown in blue). Solid contours show where each event is likely to be visible through binoculars at a reasonable altitude in the sky. Dotted contours indicate where each event occurs above the horizon, but may not be visible due to the sky being too bright or the Moon being very close to the horizon.

Map showing where the occultation is visible

Outside the contours, the Moon will not pass in front of Regulus (Alpha Leonis) at any time, or is below the horizon at the time of the occultation. However, a close conjunction between the pair will be visible across much of the world.

The map can be downloaded in PNG , PDF or SVG format. A KMZ file , is also available, which can be opened in Google Earth to provide a higher resolution map.

A complete list of the countries and territories where the occultation will be visible is as follows:

Country Time span
(UTC)
Colombia 01:48–03:06
Peru 02:04–03:06
Mexico 01:00–02:44
Venezuela 01:57–03:02
Brazil 02:04–03:06
Ecuador 01:52–03:06
Cuba 01:41–02:31
Nicaragua 01:40–02:54
Honduras 01:36–02:49
Guatemala 01:30–02:47
Panama 01:49–02:59
Costa Rica 01:44–02:57
Dominican Republic 02:00–02:37
Haiti 01:57–02:36
Belize 01:34–02:43
El Salvador 01:35–02:49
Jamaica 01:51–02:38
Puerto Rico 02:06–02:32
The Contiguous United States 01:12–02:14
Bahamas 02:02–02:24
British Virgin Islands 02:10–02:27
Cayman Islands 01:47–02:35
Curacao 02:00–02:50
Saint Kitts and Nevis 02:09–02:32
U.S. Virgin Islands 02:08–02:31
Anguilla 02:12–02:26
Bonaire, Saint Eustatius and Saba 02:01–02:49
Montserrat 02:09–02:32
Aruba 01:59–02:49
Sint Maarten 02:11–02:27
Saint Barthelemy 02:11–02:27
Saint Martin 02:12–02:26
Clipperton Island 01:10–02:29
Navassa Island 01:56–02:35

Lunar occultations are only ever visible from a small fraction of the Earth's surface. Since the Moon is much closer to the Earth than other celestial objects, its exact position in the sky differs depending on your exact location on Earth due to its large parallax. The position of the Moon as seen from two points on opposite sides of the Earth varies by up to two degrees, or four times the diameter of the full moon.

This means that if the Moon is aligned to pass in front of a particular object for an observer on one side of the Earth, it will appear up to two degrees away from that object on the other side of the Earth.

At the time of the occultation, the Moon will be 0 days past new moon and will be 27% illuminated. Regulus (Alpha Leonis) will disappear behind the unilluminated side of the Moon and reappear from behind the illuminated side of the Moon.

The position of Regulus (Alpha Leonis) at the moment of the occultation will be as follows:

Object Right Ascension Declination Constellation Magnitude Angular Size
Regulus (Alpha Leonis) 10h08m20s 11°58'N Leo 1.4 0'00"

The coordinates above are given in J2000.0.

Next/previous occultations

« Previous Next »
Visible from the Contiguous United States Worldwide Worldwide Visible from the Contiguous United States
14 May 1970 21 May 1980 Occultations of Regulus (Alpha Leonis) 15 Jul 1980 01 Nov 1980
18 Apr 1980 23 May 1980 Occultations 19 Jun 1980 09 Jul 1980

The sky on 25 May 2025

The sky on 25 May 2025
Sunrise
05:41
Sunset
19:53
Twilight ends
21:34
Twilight begins
04:01

28-day old moon
Waning Crescent

0%

28 days old

Planets
Rise Culm. Set
Mercury 05:26 12:25 19:24
Venus 03:31 09:49 16:08
Moon 04:19 11:23 18:37
Mars 11:07 17:58 00:49
Jupiter 07:10 14:21 21:31
Saturn 02:43 08:40 14:37
All times shown in PDT.

Source

The circumstances of this event were computed using the DE430 planetary ephemeris published by the Jet Propulsion Laboratory (JPL).

This event was automatically generated by searching the ephemeris for planetary alignments which are of interest to amateur astronomers, and the text above was generated based on an estimate of your location.

Image credit

The Moon in conjunction with Venus and Jupiter, with the Very Large Telescope in the foreground. Image © Y. Beletsky, ESO, 2009.

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South El Monte

Latitude:
Longitude:
Timezone:

34.05°N
118.05°W
PDT

Color scheme