Starwatch: The best, though briefest, starwatching of the year begins
June is tough on stargazers because it has the shortest nights of the year. You have to wait until late in the evening to take in the starry show.
Good stargazing can’t really begin until after 10 p.m., and the show is pretty much over by 4:30 a.m., when morning twilight begins. Get your afternoon nap so you can enjoy nature’s late, late summer star show. Remember to have the mosquito juice at the ready!
The transition in the night sky is just about complete. The stars and constellations of winter are pretty much gone from our skies, all setting well before the sun. Among the few bright winter stars left are Castor and Pollux in the constellation Gemini the Twins. You can see them side by side in the low northwestern sky toward the end of evening twilight, between 9:30 and 10 p.m.
The brightest “star” in the evening sky is actually the planet Jupiter, beaming away in the south-southwest early evening sky. Just to the lower left of Jupiter is the star Spica, the brightest star in the very large but very faint constellation Virgo the Virgin.
This month, Jupiter is around 460 million miles from Earth. The two planets were at their closest approach to each other in April when they were around 416 million miles apart. Even though it isn’t quite as close to our backyards now, Jupiter is still a lot of fun to look at, even with a small telescope. You can easily see up to four of its orbiting moons that resemble tiny stars on either side of the planet. You might even see some of Jupiter’s cloud bands stretching across the 88,000 mile-wide planet.
If you can manage to stay up past 11 p.m., you’ll see Saturn rising in the very low southeastern sky. It’s the brightest star-like object in that part of the sky. This month, Saturn and Earth reach their closest approach to each other for 2017. It’s still a heck of a long ways from Earth, at around 840 million miles away, but because it’s the second-largest planet in our solar system, it’s an absolute delight to ponder with even a small telescope.
You can see the massive ring system of Saturn and at least some of its many moons. I have to warn you, though, that until Saturn reaches a high point in the southeastern sky after midnight, it will be a really fuzzy image through any size telescope because of the blurring effect of the thicker layer of atmosphere close to the horizon. I’ll have much more on Saturn later this month.
If you lie back on that reclining lawn chair and look straight overhead toward the zenith, you’ll easily see the nearly upside-down Big Dipper, and not far from the end of the Dipper’s handle you’ll see a bright orange star. That’s Arcturus, the second-brightest star in the sky, which is about 36 light-years or 208 trillion miles away (give or take a billion miles).
The light that we see tonight from Arcturus, almost 70 times the diameter of our sun, left that star when Gerald Ford was our President. Arcturus is also the brightest star in the constellation Bootes the hunting farmer, which actually looks more like a giant nocturnal kite with Arcturus at the tail of the kite.
Over in the eastern skies, the stars of summer are making their initial evening appearance. Leading the way is Vega, the brightest star of Lyra the Harp. A little to the lower left of Vega is Deneb, the brightest shiner in Cygnus the Swan, otherwise known as the “Northern Cross,” rising sideways in the east.
Deneb lies at the head of the cross and is at least 1,500 light-years from Earth. Deneb is a moderately bright star in our sky, but looks are deceiving. It’s almost 400,000 times more powerful than our sun and over 250 million miles in diameter. Our own sun is less than a million miles in girth. Deneb would be a whole lot brighter in our sky except that it’s so very far away.
We’re drawing closer to a fantastic celestial happening. On Aug. 21, we’ll have a total eclipse from coast to coast in a narrow strip that runs from Oregon to South Carolina. I’ve seen a total eclipse and believe me, if you have a chance to travel and see it, do so! I guarantee it will be worth it!
Around here it will be a deep partial eclipse with about 80 percent of the sun’s disk being covered by the moon. You need to wear specialized eclipse glasses to watch any partial eclipse. It’s not safe staring at the sun without them. You could do great harm to your eyes. Safety first!