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. 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.

Unfortunately the occultation will not be visible from Cambridge.

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.

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.

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
19 Aug 2021 03 Oct 2022 Occultations of Sigma Sagittarii (Nunki) 26 Nov 2022 20 Jun 2027
12 Oct 2022 27 Oct 2022 Occultations 08 Nov 2022 08 Dec 2022

The sky on 30 Oct 2022

The sky on 30 October 2022
Sunrise
07:12
Sunset
17:40
Twilight ends
19:15
Twilight begins
05:37


Waxing Crescent

34%

5 days old

Planets
Rise Culm. Set
Mercury 06:43 12:06 17:28
Venus 07:23 12:35 17:47
Moon 13:20 17:32 21:47
Mars 20:10 03:49 11:27
Jupiter 16:10 22:07 04:04
Saturn 14:31 19:32 00:32
All times shown in EDT.

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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