Lunar occultation of Sigma Sagittarii

Dominic Ford, Editor
From the Lunar Occultations feed


Objects: Nunki

The Moon will pass in front of Sigma Sagittarii (Nunki), creating a lunar occultation visible from countries and territories including southern Mexico, Hawaii, north-western Kiribati and north-eastern French Polynesia amongst others. 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 Fairfield. It will begin with the disappearance of Sigma Sagittarii (Nunki) behind the Moon at 08:13 EDT, though in daylight and at a low altitude of only 8.0 degrees, in the south-western sky. Its reappearance will be visible at 08:40 EDT, though in daylight and at a low altitude of 4.3 degrees.

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 Sigma Sagittarii (Nunki) 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.

Outside the contours, the Moon will not pass in front of Sigma Sagittarii (Nunki) 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)
Mexico 11:17–12:27
Hawaii 09:12–10:08
Kiribati 09:02–10:03
French Polynesia 09:22–10:24
Kingman Reef 09:02–10:02
Palmyra Atoll 09:02–10:02
Clipperton Island 10:39–12:01
Jarvis Island 09:07–09:57

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 77% illuminated. Sigma Sagittarii (Nunki) will disappear behind the illuminated side of the Moon and reappear from behind the unilluminated side of the Moon.

The position of Sigma Sagittarii (Nunki) at the moment of the occultation will be as follows:

Object Right Ascension Declination Constellation Magnitude Angular Size
Sigma Sagittarii (Nunki) 18h55m10s 26°17'S Sagittarius 2.1 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
26 Sep 2058 08 Apr 2064 Occultations of Sigma Sagittarii (Nunki) 01 Jun 2064 29 Jun 2064
18 Oct 2063 03 May 2064 Occultations 30 May 2064 29 Jun 2064

The sky on 22 Nov 2024

The sky on 22 November 2024
Sunrise
06:47
Sunset
16:28
Twilight ends
18:05
Twilight begins
05:10


Waning Crescent

45%

21 days old

Planets
Rise Culm. Set
Mercury 08:40 13:06 17:32
Venus 10:13 14:39 19:06
Moon 22:16 05:32 12:36
Mars 20:52 04:15 11:38
Jupiter 17:26 00:53 08:20
Saturn 13:09 18:41 00:13
All times shown in EST.

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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