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April 2023 Astronomy Events

April 2023 Astronomy Events

AstroTelescopium Team |

April 2023 is a spectacular month for celestial activity. Early in the month Mercury reaches its greatest elongation shining brightly in the evening sky. Mid month brings a rare hybrid solar eclipse and a meteor shower. And, the month ends with an Asteroid opposition.

(Looking to review last month's astronomy events? View March 2023)

Our highlighted list of astronomy events for April serves as a reference for the key astronomical events for you to be aware of.


8 Astronomical Events in April 2023:

For simple navigation, you can click on a specific event listed above to go directly to that section of the article. Below, we will explore each of these events in more detail.

Before we get started, let's briefly define a few terms used throughout this article that you should be familiar with:

Magnitude - Magnitude is simply the measure of an object's brightness. The lower the number the brighter the object. Conversely, the higher the number the fainter the object. For example, a magnitude -7.2 object is brighter than a magnitude +3.6 object. Without optical assistance, the naked eye can see a celestial object as dim as roughly magnitude +6.0.

Right Ascension - Right ascension is the celestial equivalent of geographic longitude. It is measured from the Sun's position during March Equinox at 00h00m00s (h=hours, m=minutes, s=seconds). This measurement increases towards the east until it completes a full circle at 24h00m00s.

Declination - Declination is the celestial equivalent of geographic latitude. It is measured northward or southward of the celestial equator as degrees (°), minutes(') and seconds ("). For example, the celestial equator has a declination of 0°0'0", the north celestial pole has a declination of +90°0'0" and the south celestial pole has a declination of -90°0'0".

AU (astronomical unit) - AU is a unit of length that measures the distance from the Earth to the Sun.

Angular Size - Angular size refers to a celestial object's apparent size as seen from an observer on Earth. It is measured in arcminutes(') and arcseconds(").

Conjunction - A conjunction occurs when two or more celestial objects share the same right ascension.



Astronomy events to mark on your April 2023 calendar:


April 6th - Full Moon | Pink Moon

Full Moon

The month starts off with the first Full Moon of the Spring season occurring on Thursday, April 6th at 12:34am EST. At this time, the Moon will reach peak illumination in its 29.5 day lunar cycle.

Anytime the Moon's ecliptic longitude appears 180° away from the Sun's ecliptic longitude, as observed from Earth, we experience a Full Moon.

According to the Farmers' Almanac, in Native American cultures the Full Moon that occurs during this time of year is referred to as the Pink Moon. The name derives from the wild ground phlox, a type of pink flower that blooms at this time.

This Pink Moon will appear positioned in the Virgo constellation at right ascension 13h00m40s and a declination of 4°43'S. Its angular size will be 30'32".

During this time, the moon will rise above the eastern horizon around sunset (7:25pm EST) and set below the western horizon around sunrise the following day.

As far as naked eye observations of the Moon goes, Full Moon phases are beautiful to witness. However, try not to plan on star cluster or detailed planetary observations because the Moon's bright illumination may hinder your views.


April 11th - Mercury at Greatest Eastern Elongation


Mercury will appear at its widest separation from the Sun on Tuesday, April 11th at 2:51pm EST. The planet will be positioned 17° east of the Sun shining at magnitude 0.0.

This is referred to as its greatest eastern elongation. These wide separation moments occur roughly once every 3-4 months.

During the exact moment, Mercury will be positioned in the Aries constellation at right ascension 02h29m10s and a declination of 17°34'N.

Due to Mercury's close proximity to the Sun, the planet is often difficult to safely observe since accidentally looking directly at the Sun can be damaging to your eyes. Additionally, the Sun's glare outshines any celestial object in close proximity rendering them hard to view.

For stargazers, the exact dates of Mercury's greatest eastern elongation and its greatest western elongation are significant moments. They provide an opportunity for more optimal observations of the closest planet to the Sun.

At its greatest eastern elongation, Mercury will be visible after sunset shining in a thin crescent phase.


April 13th - 3rd Quarter Moon

3rd Quarter Moon

The Moon will arrive at its last quarter phase of its 29.5 day lunar cycle on Thursday, April 13th in the Sagittarius constellation.

The exact moment will occur at 5:11am EST when the Moon is positioned at right ascension 19h42m30s and a declination of 26°35'S. Its angular size will be 31'56".

In the Northern Hemisphere, the Moon will appear half illuminated on its western side. This is known as a waning crescent Moon.

From our perspective on Earth, the third quarter moment occurs when the Moon's ecliptic longitude is 90° away from the Sun's ecliptic longitude. On this day, the Moon will rise above the eastern horizon around 2:50am EST and set below the western horizon at approximately 11:49am EST.


April 20th - New Moon

New Moon

On Thursday, April 11th at 12:13am EST, the Moon will reach its New Moon phase of its 29.5 day lunar cycle.

The Moon will appear positioned in the Aries constellation at right ascension 01h50m20s and a declination of 10°56'N. Its angular size will be 31'46".

The New Moon phase occurs every 29.5 days when the Moon and the Sun appear to be positioned at the same ecliptic longitude.

The reduced light exposure provides a beneficially dark sky for stargazers. This night is often a great opportunity for observations of higher magnitude star clusters and celestial objects that are difficult to view under more illuminated conditions.


April 20th - Hybrid Solar Eclipse

Solar Eclipse

If you are fortunate enough to be located in Western Australia, Indonesia, and Papua New Guinea, you will be able to witness a hybrid solar eclipse on Thursday, April 20th.

solar eclipse is an astronomical event that occurs when the Moon crosses the ecliptic plane at a lunar node during its new phase of its 29.5 day cycle. At that moment, from our perspective on Earth, the Moon and the Sun appear to be positioned at the same ecliptic longitude.

A hybrid solar eclipse occurs when certain points on Earth observe the event as a total solar eclipse while other points on Earth observe the event as an annular solar eclipse.

The next solar eclipse will occur on October 14th, 2023. It will be an annular solar eclipse that can be witnessed in Western U.S., Mexico, Central and South America. An annular solar eclipse occurs when the Moon is in line with the Sun but appears smaller in size than the Sun, thereby displaying a bright ring.


April 22nd - Lyrids Meteor Shower Peak

Meteor Shower

The Lyrids meteor shower will be active from April 16th through April 25th, reaching its peak on Saturday, April 22nd around 9pm EST. Its radiant point, the area from which the shower appears to emanate, is positioned in the Lyra constellation.

The meteor shower's ZHR will be 18, according to the American Meteor Society. ZHR is an abbreviation for Zenithal Hourly Rate and is defined by the rate a meteor shower would produce with a clear, dark sky, with the radiant at the zenith (highest point directly above the observer).

The Lyrids originate from comet C/1861 G1, which was discovered on April 5, 1861 by A. E. Thatcher.

A few tips for viewing the Lyrids:

  • Do not direct your gaze solely towards the radiant point. The closer a meteor is in proximity to its radiant point, the more difficult it is to spot due to its shorter trail.
  • Place yourself in a dark, secluded location away from light pollution and bright city lights.
  • Allow for up to 30 minutes for your eyes to properly adjust to the dark environment.
  • Make sure to dress appropriately for the cold winter temperatures.
  • Bring a comfortable lawn chair to recline in or a blanket to lie back on.
  • Try to observe as wide an area of the sky as possible. The broader your view of the sky, the higher the chance of catching a glimpse of a meteor whiz by.


April 27th - 1st Quarter Moon

1st Quarter Moon

On Thursday, April 27th at 5:20pm EST, the Moon will reach the first quarter phase of its lunar cycle. During this part of its 29.5 day lunar cycle, it appears high in the sky around sunset.

From the Northern Hemisphere, the Moon will appear half illuminated on its eastern side. This is also known as a waxing crescent Moon. It will be positioned in the Cancer constellation at right ascension 08h43m30s and a declination of 23°36'N. Its angular size will be 29'32".

The first quarter moment occurs when the Moon's ecliptic longitude is 90° away from the Sun's ecliptic longitude, from our perspective on Earth. On this day, the Moon will rise above the eastern horizon at approximately 11:33am EST and will set at approximately 2:58am EST.

Although many mistakenly believe that the best time to observe the Moon is when its at the Full Moon phase, the first quarter phase is generally considered the ideal time for Moon observations. Details of the Moon that are less discernible during a Full Moon are much more pronounced during the first quarter Moon.


April 30th - Asteroid 7 Iris at Opposition


On Sunday, April 30th at 12:46pm EST, the asteroid 7 Iris will reach opposition. When a celestial object is "at opposition", this refers to its 180° position opposite to the Sun.

At this time, 7 Iris will be located in the Libra constellation positioned at right ascension 14h22m00s and a declination of 19°49'S.

7 Iris will also be at perigee (closest proximity to Earth) at a distance of 1.92 AU and the asteroid will appear brightest to us in the night sky at magnitude +9.6.



Start viewing

Now that you have a better idea of the events in the night sky this month, the fun part is to actually observe them. Many of the events discussed can be seen without special optical equipment. However, a quality pair of binoculars or a premium telescope will significantly enhance your viewing experience.

If you're in the market for purchasing or upgrading your astronomy gear, we have a curated selection of binoculars, telescopes and accessories to choose from. Our online store offers high quality optics from industry-leading brands at value prices to help you explore the world above.

Feel free to browse our telescope collection or browse our binoculars.

If you're unsure where to start you can read through How To Choose The Right Telescope or How To Choose The Right Binoculars for additional guidance.


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