Mercury at dichotomy

Dominic Ford, Editor
From the Inner Planets feed


Objects: Mercury

Mercury will reach half phase in its Jun–Jul 2173 morning apparition. It will be shining brightly at mag -0.1.

From Jacksonville , this apparition will not be one of the most prominent and tricky to observe, reaching a peak altitude of 16° above the horizon at sunrise on 28 Jun 2173.

Jun–Jul 2173 morning apparition of Mercury

27 May 2173 – Mercury at inferior solar conjunction
22 Jun 2173 – Mercury at greatest elongation west
27 Jun 2173 – Mercury at highest altitude in morning sky
28 Jun 2173 – Mercury at dichotomy
21 Jul 2173 – Mercury at superior solar conjunction

A graph of the phase of Mercury is available here.

Apparitions of Mercury

12 Jan 2173 – Evening apparition
22 Feb 2173 – Morning apparition
04 May 2173 – Evening apparition
22 Jun 2173 – Morning apparition
01 Sep 2173 – Evening apparition
14 Oct 2173 – Morning apparition
27 Dec 2173 – Evening apparition

Observing Mercury

Mercury's orbit lies closer to the Sun than the Earth's, meaning that it always appears close to the Sun and is lost in the Sun's glare much of the time.

It is observable for only a few weeks each time it reaches greatest separation from the Sun – moments referred to as greatest elongation. These apparitions repeat roughly once every 3–4 months.

Mercury's phase

Mercury's phase varies depending on its position relative to the Earth. When it passes between the Earth and Sun, for example, the side that is turned towards the Earth is entirely unilluminated, like a new moon.

Conversely, when it lies opposite to the Earth in its orbit, passing almost behind the Sun, it appears fully illuminated, like a full moon. However, at this time it is also at its most distant from the Earth, so it is actually fainter than at other times.

Mercury shows an intermediate half phase – called dichotomy – at roughly the same moment that it appears furthest from the Sun, at greatest elongation. The exact times of the two events may differ by a few days, only because Mercury's orbit is not quite perfectly aligned with the ecliptic.

Mercury's position

The coordinates of Mercury when it reaches dichotomy will be:

Object Right Ascension Declination Constellation Angular Size
Mercury 04h47m00s 19°47'N Taurus 7.1"
Sun 06h19m 23°20'N Gemini 31'28"

The coordinates above are given in J2000.0.

The sky on 3 Jul 2024

The sky on 3 July 2024
Sunrise
06:26
Sunset
20:32
Twilight ends
22:08
Twilight begins
04:49


Waning Crescent

2%

27 days old

Planets
Rise Culm. Set
Mercury 07:58 14:54 21:50
Venus 07:03 14:03 21:04
Moon 03:57 11:21 18:50
Mars 02:57 09:39 16:21
Jupiter 04:10 11:05 18:00
Saturn 00:13 06:01 11:50
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.

Related news

27 Jun 2173  –  Mercury at highest altitude in morning sky
24 Aug 2173  –  Mercury at highest altitude in evening sky
01 Sep 2173  –  Mercury at greatest elongation east
14 Oct 2173  –  Mercury at highest altitude in morning sky

Image credit

© NASA/JPL/MESSENGER

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