Astronomy: The Week Ahead – Sun 5 Apr to Sat 11 Apr 2015

Sunrise in Space via the ISS. Credit: NASA & ESA

Sunrise in Space via the ISS.
Credit: NASA & ESA


Sunday April 5

Pluto is at Western Quadrature this morning, 90 degrees west of the sun from us at is heads toward morning twilight. It is located conveniently in the Teaspoon asterism of Sagittarius, an easy location to see with the naked eye. Pluto will require a telescope and detailed chart.


Monday April 6

Between Leo and Hydra is the dim constellation Sextans, a modern creation introduced in 1687 by Johannes Hevelius. Use Regulus in Leo and Alphard in Hydra to help locate it. Sextans is rich in deep sky targets, as it covers an area away from the Milky Way.

Today, just before sunrise, Uranus reached conjunction with the sun. The sun lies between us. You can imagine this, as the constellation Sextans near tonight’s “anti-solar point”, the point in the sky the sun. In a truly dark sky, you can see the anti-solar point, it’s called “Gegenshein”.


Tuesday April 7

It’s time to bid a fond adieu to some favorite winter constellations. Canis Major, Orion and Taurus are now sinking into the early evening twilight. They will make a lovely sight this evening!


Wednesday April 8

A bright waxing gibbous moon, 85% illuminated, pairs closely in the southwestern morning sky with creamy yellow Saturn, in Scorpius. The pair are under a degree and a half apart, and will look great together in binoculars or a wide-field telescope. This also presents a great imaging opportunity!


Thursday April 9

Two solar system events occur today. Beginning at 22:51 PDT Jupiter’s moon Io begins a transit across the disk of the planet. At 23:12 you’ll see the Great Red Spot (GRS) appearing on the planet’s limb, then at 00:02 on 4/10, its shadow ingresses, quickly catches up to and passes the GRS. By 02:23 all the Io action comes to an end. Get out your telescope and watch, you’ll be amazed at Io’s speed!

Today Mercury is at Superior Conjunction. Just like Uranus a few days ago, this speedy little planet is on now the exact opposite side of the sun from us.


Friday April 10

M51 is the famous Whirlpool Galaxy, near the equally famous asterism called The Big Dipper, part of the constellation Ursa Major. M51 lies just across the constellation boundary in Canes Venatici, the Hunting Dogs, anchored by the bright star Cor Caroli (the Heart of Charles). In a dark sky, M51 shows nice spiral structure in a telescope. This is the beginning of the season to observe it in the early evenings, as it is rising. It lies 23 million light years distant, and shines at magnitude 8.4, but seems somewhat dimmer due to its large size of 9.8 arc minutes. This is a great target to observe!


Saturday April 11

The last quarter Moon is tonight, giving us Saturday with plenty of time for dark sky astronomy. Spica, rising east after sunset ushers in galaxy season, with Virgo, Leo and Coma Berenices chock full of treasures.

Enjoy & happy viewing!