What's Up: August 27 - September 3, Jared May

I hope you have all your stargazing equipment ready because the forecast is showing multiple clear nights this week – a rare event! The temperatures will be in the low-70s and upper-60s in the hours following sunset which occurs around 8:05 PM. The twilight sky should fade to astronomical dark by around 9 PM. During the clear nights this week be on the lookout for the blue supermoon (a two-for-one deal), all the outer planets, and Cygnus the Swan directly overhead.

The Full Moon- a blue moon, but not blue in color

On Wednesday, August 30th at exactly 9:36 PM, the moon will be full. This will make the second full moon of August and the second full moon of any month is referred to as a “blue moon”. Blue moons typically occur around once every two to three years. So now you know for when someone uses the age-old saying “once in a blue moon”, they precisely mean “once every two or three years”. The supermoon title gets added because the moon is near its perigee, or closest point to Earth in its orbit. An average supermoon will actually only be about 14% larger in diameter but up to 30% brighter than when at apogee (its furthest point from Earth).

Any time this week, if you are still out stargazing around midnight, you will be able to see all of our solar system’s outer planets; Jupiter, Saturn, Uranus, and Neptune. Jupiter and Saturn will be easy to spot with the naked eye, but Uranus and especially Neptune will require a higher-power telescope (focal length >700mm).

The outer planets march across the evening sky. Saturn and Jupiter can be seen with the naked eye. Uranus and Neptune cannot.

Uranus and Jupiter will be right next to each other. A telescope will reveal the red stripes of Jupiter and four of its largest moons. Uranus is a little less exciting through a telescope, you will only be able to see this planet as a blue-colored point of light. Fun fact about Uranus, it is the only planet in the solar system that rotates on its side (its northern hemisphere gets half a year (42 earth years) of daylight, then its southern hemisphere gets half a year of daylight).

Uranus, the Sideways planet. photo: https://www.nasa.gov/mission_pages/chandra/images/first-x-rays-from-uranus-discovered.html an x-ray image of Uranus taken using the Chandra X-ray space telescope (purple tint) and superimposed on a visible light image. It is easy to see the planet is rotating on its side.

Neptune will be floating close to Saturn as seen from Earth (though they are quite far away in reality.) A telescope will reveal Saturn’s grand rings that may even look a bit brighter than usual. When viewed when the sun is backlighting the earth (around midnight), something called the Seeliger effect will make the rings appear slightly brighter. Neptune, very similar to Uranus, will only appear as a blue-colored point source.

If you look directly overhead anytime this week, you will see the constellation of Cygnus the Swan. This is an easy-to-spot constellation since it is comprised of brighter stars and it is home to many fantastic deep-sky nebulae. Some of these include the Veil Nebula, Crescent Nebula, Pelican Nebula, the North America Nebula, and many more. A telescope and adequate dark skies will reveal a hazy light for the brighter nebulae. While this is not a good week for observing the veil nebula with your eye (using a telescope) a camera capable of taking long-exposure images is perfect for soaking up all the light and making these emission regions pop out against the black of space.

Cygnus is high overhead once it is fully dark this week.

The bright moonlight this week will wash out the veil, but astro-cameras can still capture good images of it if skies are clear. This is a close up image of a small part of the veil.

The image above is Hubble’s take on a very small region of the Veil Nebula (most amateur telescope focal lengths are between 500 and 1000mm, Hubble has a focal length of 57,600mm – now that’s a lot of zoom!). The color is a result of various optical filters producing a false-color image.

Make sure to get outside this week and take full advantage of the multiple clear skies. If you can’t get out to stargaze for all the nights, at least there are multiple options. Bring a jacket and a reclining chair or a towel to comfortably gaze upwards into the heavens. The universe, our galaxy, and our local solar system are all teeming with amazing displays. Be on the lookout for the rare blue supermoon, all the outer gas giants, and just one of many regions of the sky filled with deep-sky nebulae. Clear Skies!