At any moment of the day, countless awe-inspiring celestial events are unfolding in the sky. With a universe of options, it can be hard to pin down what to observe. The purpose of this calendar is to provide a peek into what’s happening in the sky and in the world of astronomy in general and give a quick list of highlights that can jump start your own explorations.
April 2 – Conjunction of Moon and Jupiter
Two of the brightest celestial objects will pair up in the night sky on April 2 as Jupiter reaches conjunction with the waxing crescent Moon. Although both will lie in the constellation Taurus, they will not be close enough to observe together in a telescope’s field of view. However, the pairing can be easily enjoyed by the naked eye. With the naked eye, Jupiter will manifest as a bright point of light, but a modest telescope may reveal the giant planet’s impressive cloud belts, its turbulent Great Red Spot or any of the four Galilean moons. If your viewing conditions are right, this might also be an opportune time to check out the Pleiades star cluster, which will be sharing the same celestial real estate as the pairing. Also known as the Seven Sisters, the Pleiades is defined by its brilliant blue stars and has a rich lore that goes back thousands of years. A dark sky free of light pollution can help a dedicated observer see around a dozen Pleiades stars, but a good pair of binoculars or a low-power telescope can quickly reveal the more elusive members of this legendary cluster.
Astrophotographer Larry Byrge captured this image of the Pleiades star cluster with the aid of an Explore Scientific ED102 Air-Spaced Triplet Refractor.
April 12 – Yuri’s Night
When it comes to space exploration, April 12th has long held profound significance. It was on that date in 1961 that cosmonaut Yuri Gagarin became the first human in outer space after he blasted off for a 108-minute flight aboard the Soviet space program’s Vostok 1 spacecraft. Although brief, this journey was a monumental milestone that ignited an international passion for space exploration. To commemorate this historic event and ensure that passion continues to thrive, organizers held the first Yuri’s Night on April 12, 2001, and, it has grown every year since. Dubbed a World Space Party, the event is a “global celebration of humanity’s past, present and future in space.” Although the anniversary of Yuri Gagarin’s flight is the foundation of the celebration, it also coincides with another April 12th milestone - the 1981 inaugural launch of NASA’s Space Shuttle, which was the world’s first reusable spacecraft and a catalyst for international cooperation. For more information or a schedule of the hundreds of related parties across the globe, visit yurisnight.net.
April 21 – Mercury at Greatest Western Elongation
On April 21, Mercury will be a bright presence in the pre-dawn sky — especially for those in the Southern Hemisphere — as the planet achieves a prime position for early morning viewing. Because it is always so close to the Sun, Mercury is usually lost in its glare. But on this day, it will be at its greatest western elongation or at its furthest point to the west of the Sun, which means it will rise well before the Sun in some places. A clear sunrise horizon is essential for viewing Mercury. While this often-elusive planet will be visible to the naked eye, a pair of binoculars or a small telescope could provide additional details.
April 21/22 – Lyrids Meteor Shower Peak
In mid-April, one of the oldest known meteor showers on record will take its annual turn through the night sky. The Lyrids, which are caused by the Earth’s passage through debris left behind by Comet C/1861 G1 Thatcher, are set to peak in the predawn hours of April 22 with an average hourly meteor count between 10 and 20. The waning crescent moon, which will rise around the predicted peak time, will be bright enough to interfere with meteor hunting, so it might be best to turn an eye to the sky in the late evening of April 21 until moonrise on April 22. Especially favorable for the northern hemisphere, the Lyrids appear to radiate from a point near the bright star Vega in the Lyra constellation. However, observers should actually look at a dark patch of sky about 90 degrees away from the radiant point to see the most meteors. To view the Lyrid meteors, which have been known to briefly leave behind glowing dust trails, all you need is your naked eye and a good place to lie down under an open sky.
CONSTELLATION SPOTLIGHT:
Leo Constellation
Observers wanting to make the most of a mild April night can find an abundance of brilliant stars and inspiring galaxies in the Leo constellation as it prominently prowls the celestial ecliptic. Visible from 90° north to 65° south, the “Lion” covers a 947 square degree area and has a rich history as one of the earliest recognized constellations. One of its main attractions is its brightest star - the well-known Regulus, or “Little King,” which pops in the night sky even to the unaided eye. Boasting an apparent visual magnitude of 1.35, this blue-white beauty anchors the sickle-shaped asterism that defines the head of the lion and is said to represent the beast’s heart. Regulus is actually a multiple star system that can be at least partially resolved with binoculars. Its dominant component has an interesting oblate shape due to rapid rotation.
Another must-see target in Leo’s sickle is Algieba (gamma Leonis), a double star system consisting of two giant stars, one casts an orange-red hue and the other a fainter yellow-green. Representing the tail of the lion is Denebola - a naked eye star that is also a member of the IC 2391 super cluster, which is a collection of stars that are not gravitationally bound but share a common motion through space. Other notable stars include R Leonis, a giant pulsating variable that is very red and undergoes wide swings in magnitude, and the elusive large-scope target Wolf 359, a faint red dwarf that is one of the lowest-mass stars yet discovered.
Astrophotographer Christopher Sullivan captured this image of the Leo Triplet galaxy group with the aid of an Explore Scientific f/3.9 N208-CF Newtonian and HR Variable Coma Corrector.
In addition to its impressive stellar offerings, Leo is also an excellent source of observable galaxies. The Leo Triplet Galaxy Group consists of the intermediate spiral galaxies Messier 65 and Messier 66 as well as the edge-on unbarred spiral galaxy NGC 3628, which has a distinct band of dust. Other galaxies to explore are the barred spiral galaxy Messier 95, which has a distinct ring-shaped star-forming region surrounding its core; the intermediate spiral galaxy Messier 96 and the elliptical galaxy Messier 105. The constellation is also home to the Leo Ring, a cloud of helium and hydrogen gas that is orbiting two galaxies.
WANT TO NAVIGATE THE NIGHT SKY WITH EASE?
The Tirion Double-Sided Multi-Latitude Planisphere is a comprehensive sky map for northern hemisphere stargazers located between the equator and latitude 60° north that makes it easy to identify what constellations and major celestial objects are up in your night sky based on the date and time.
This night sky guide, which features maps crafted by noted celestial cartographer Wil Tirion, uses a double-sided design to minimize the distortion that is inherent to any polar-centered projection. This design choice means observers can see truer representations of the constellations located outside the equator (noted by a green line) by simply flipping the planisphere over.
In addition to showcasing constellations, this planisphere indicates the location of notable variable stars, open clusters, nebulae and galaxies. Other features include a line representing the ecliptic, a faint blue band for the Milky Way and a magnitude scale that indicates the brightness of the stars that are shown.
This astronomy planisphere is made of durable plastic that easily wipes clean, and the rotating components are secured with sturdy brass rivets for smooth manipulation. Guidance for using your sky map is printed on the device for quick reference.