The month of April is named after Aprilis, which means aperture, since April is the month of opening. We have had one of the warmest winters on record, so we will wait and see what this spring will bring as life returns to the Earth in the northern hemisphere.

As the nights continue to get shorter and warmer now, all five of our brightest planets are still visible in the evening sky. However, Jupiter is beginning to drop out of the picture, and Mercury is having a poor apparition this month and may only be visible using binoculars.

Even more exciting than our continuing and rare dance of the planets is the discovery of two new supernovae in nearby galaxies just a few weeks ago. The first one was discovered March 14, which is Einstein’s birthday, in a galaxy called NGC 4790, about 60 million light years away in the constellation of Virgo.

Named 2012au, this was a Type 1B supernova, which is a single massive star that explodes to end its life. All of the fuel in its core runs out, and there is no more fusion pressure to fend off the enormous gravity of the weight of all the gas.

The star implodes first, which sets up a shock wave that rebounds and then rips the whole star apart in a matter of seconds. It takes thousands of years for the star to run out of fuel, but once that happens, it is only a matter of seconds for its final explosion.

Even though most of this energy is not even released in the form of visible light, a supernova does become billions of times brighter than it was before. It usually becomes about as bright as the entire galaxy it used to live in.

NGC 4790 is a 12.4 magnitude galaxy, and the supernova is about the same brightness, making them both visible in average telescopes. If the supernova keeps getting brighter as expected, it would even become visible in a small telescope. That would allow many more people on Earth to see and appreciate a cataclysmic event like this, like the one that created the heavier elements that make up the Earth, along with the plants, animals and people living here.

This galaxy is located close to Saturn, about the same distance up and to the right of Spica in Virgo as Saturn is up and to the left of Spica. The supernova is near the center of this galaxy.

The other and even more dramatic supernova was found just two days later in the galaxy called M95 in Leo the Lion. This galaxy, about 38 million light years away, is very close to Mars now, so it is easy to find in the sky. At a magnitude of 9.7, it is also about 10 times brighter than NGC 4790.

The supernova is much farther from the center of M95, so it will be easier to see. It is already brighter than 12th magnitude, and is also expected to get much brighter quickly, until it fades out again in about a month.

There are also three fairly bright asteroids now visible in Leo near Mars. They are named 5 Astraea, 6 Hebe, and 8 Flora and are each about 100 miles in diameter. Being that large, they were among the first few asteroids to be discovered in the mid-1800s. They will be in the 9th to 10th magnitude range, making them visible in a small telescope.

As if rare planetary alignments, new supernovae, and asteroids and comets were not enough, there will even be a nice little meteor shower this month. The Lyrids will peak during the morning of Sunday, April 22. There will be no moon to interfere, but the Lyrids usually only produce about 12 meteors per hour from a dark sky.

Mars is now shrinking and getting dimmer at about the same rate that it was growing brighter before its opposition early last month. Mars will still be large enough to see some details in a small telescope for the rest of this month.

Saturn is right in the middle of its retrograde loop when it reaches opposition. That day it will rise at sunset and not set until sunrise. It will also be at its closest and brightest for the year that day.

APRIL HIGHLIGHTS

April 1. Comet Hale-Bopp made its closest approach to the sun on this day in 1997. This once-in-a-lifetime comet was bright enough to be seen from cities and covered nearly a quarter of the sky during most of the month of March of 1997.

April 3. Venus will be very close to the Pleiades tonight. The moon will be just below Mars tonight.

April 6. Full moon is at 3:19 p.m. EDT. This is also called the Grass, Egg, Pink, Sprouting, or Fish Moon.

 April 12. On this day in 1961, Yuri Gagarin became the first human in space. Even now, over 50 years later, only about 500 different people have been in space orbiting around the Earth.

April 13. Last quarter moon is at 6:50 a.m.

April 15. Saturn reaches opposition.

April 21. New moon is at 3:18 a.m.

April 22. The Lyrid meteor shower peaks this morning. The meteors will emanate from the constellation of Lyra.

April 25. On this day in 1990, the Hubble Space Telescope was deployed. It is still going strong 22 years and over one million pictures later. 

Bernie Reim of Wells is co-director of the Astronomical Society of Northern New England.