A Sea of Deep Space Objects

The Galactic Center

The waning days of Summer are an excellent time to enjoy a view into the heart of the Milky Way Galaxy. We observe our own galaxy all around us in the night sky, and if you are in a reasonably dark location, you can see the band of stars that are the spiral arms of our own galaxy stretch across the sky. At this time of year, as the sky darkens after sunset, the Milky Way stretches high overhead, touching the southern horizon at the constellation Sagittarius. In fact, when you look due south toward that very constellation, you are looking toward the center of the galaxy. Not surprisingly, you also can see a lot of beautiful deep space objects, and with a pair of binoculars you can see many interesting objects, from clusters of stars to nebulae. The diagram gives you an idea of the richness of this part of the sky and galaxy, and even in city lights you will still be able to spot many of these objects. A telescope is fine to use as well, but I find that binoculars give you a big picture and are quite good for seeing the colors and breadth of many of the big nebulae in and around Sagittarius. 

Six months from now, as the Earth swings around the Sun and our view of the night sky has shifted, we'll be pointing the opposite direction toward the 'antipode' of the Milky Way Galaxy, a much less interesting part of the sky (but still cosmically significant). So enjoy Sagittarius and the center of the galaxy while you can.

The Galactic Center: Staring Into the Heart of the Milky Way

Summer is prime time to look into the heavens and touch the wonder of the Galactic Center, the heart of our own Milky Way galaxy. Two bright constellations guide you to the center of the Milky Way, Scorpius and Sagittarius, which are easy to spot due south each evening shortly after sunset.

The Galactic Center

Our own Sun and Solar System occupy their special place 30,000 light years from the center of the Milky Way, and as we look out and around us into space, we view our own galaxy from within, along the spiral arms and toward the center. Many have seen the lovely band of the Milky Way when camping or far away from city lights, but the faint river of light is all but invisible in any urban area. Nonetheless, with binoculars, you can see deeper into the sky and discover some of the deep space wonders and faint objects that are visible between our own location and the center of the galaxy, an area full of star clusters and nebulae. So I encourage everyone to get a pair of binoculars, face south, and using the star chart (above) as a guide, aim between Scorpius and Sagittarius and meander from there upwards. You will encounter the Lagoon Nebula and the nearby Trifid Nebula, easily visible in city lights if you use a telescope or binoculars, and many more Messier Objects, the fuzzy blobs that dot the sky near the Galactic Center.

In six months, when the Earth has traveled half-way around the Sun, we'll be able to look in the opposite direction, toward the Galactic Anticenter, as I have described in a previous blog post. That is interesting to consider, but more exciting is the Summer when we can enjoy our own galaxy's finest wonders on full display.

Here's a link to an image of the Galactic Center on Sky & Telescope's website.

Image courtesy SkySafari.

Seeing Summer in Winter - Scorpius and Sagittarius

The early morning sky this week holds some treasures for star gazers. As the view of the heavens changes from season to season, we have a chance to see the symmetry of our sky by looking south-east in the morning. In winter, we see the majestic winter sky in the evening, but by early morning we see the summer sky! How is this possible? Every 12 hours as the Earth rotates on its axis, we face the different constellations and in fact see the "opposite" season in the morning. This week, as the old Moon passes through the summer constellations of Scorpius and Sagittarius, it accentuates the rich beauty of these two constellations, both of which contain many treasures for the unaided eye as well as for those who wish to get out their binoculars for a closer look.

Sagittarius is located in same direction as the center of the Milky Way, and Scorpius is just next to this, so both contain a richness of nebulae and star clusters that are easy to find in binoculars. It's worth the extra 2 minutes in the morning to take a look if you can get outside before the first light of dawn, before 6:00 am in San Francisco.

KFOG Podcast - September 10, 2010

Another fun visit with Irish Greg of the KFOG Morning Show, today featuring a discussion of constellations to see this time of year (Sagittarius, Scorpius, The Summer Triangle) and the difference between an asterism and a constellation, plus deep-space objects you can see in the Milky Way with an ordinary pair of binoculars. And the latest happenings with the Moon and Venus, and an update on a great star party and lecture this weekend. All in 7 short minutes! Click here to listen.

The Milky Way and the Galactic Center

At the SFAA star party a couple nights ago on Mt Tam, the conditions were very clear and dark and we had a nice view of the Milky Way. With an excellent southern horizon, we could see all of Scorpius and Sagittarius and as my daughter and I were giving star tours to guests at the star party, I was happy to point out these two constellations and note that the center of the Milky Way was in the vicinity of the tail of Scorpius and the "teapot" of Sagittarius. This is called the "Galactic Center" and is the central bulge of the Milky Way Galaxy.

Looking toward the galactic center, however, you don't see a huge ball of light. That is because there is a massive dust cloud that lies between the Sun and the galactic center. Too bad for us, because it would be quite amazing to see the center of our own galaxy. Nonetheless, there is much richness in the sky near the galactic center and even in city lights you can begin to see some of that beauty if you use a pair of binoculars. Standard 7x35 or 10x50 binoculars can substantially increase the amount of light you can see, and that means you can begin to discern the stars and shapes of deep space objects such as the Lagoon Nebula or the Swan Nebula. Take out binoculars and point yourself south and see if you can start to see some of the wonders that are at the heart of the Milky Way.