24 July 2009

The Summer Triangle

One of the brightest objects in the nighttime sky each summer is called the Summer Triangle. Rather than being a single constellation, the Summer Triangle is an "asterism," a grouping of stars that make an interesting pattern but are not themselves a single constellation. The Summer Triangle is, as advertised, a very distinctive triangle of three very bright stars that form a 30-60 right triangle. The three bright stars are Vega, Deneb and Altair. With three stars at magnitude 0 or 1, the Summer Triangle shines through even light-polluted city skies.

If you have darker skies, the Summer Triangle is a quick guidepost to locating some of the most interesting objects you can see with binoculars or a telescope in the Milky Way. The image to the right is taken from the website of the Great Smoky Mountain Astronomical Society. I like their web images because they present a very easy-to-follow guide to the most interesting objects in the part of the Milky Way that passes through the Summer Triangle, including double stars, nebulae, star clusters and the patterns of the three constellations that include the three bright stars of the Summer Triangle: Lyra, Aquila and Cygnus. For another description of the same objects, try this page from the Royal Observatory in Greenwich.

Use your binoculars or a telescope - even if you are in a big city - and see how much of these constellations you can identify and how many of the interesting objects you can find lurking in their midst.

Amateur Astronomy on KALW Radio / SFAA Star Parties

I like blogging about astronomy because I want to get the public motivated to spend a few minutes out under the stars instead of staying inside at night. To that end, I've been able to extend my reach by being a guest on KFOG radio from time to time. This week KALW, public radio at 91.7FM in San Francisco, broadcast a feature story on the San Francisco Amateur Astronomers at one of their Star Parties on Mt Tam. It's great radio and it gives you a good perspective on what you do at at Star Party. KALW also recorded a brief interview with yours truly talking about the night sky. I used to be a radio DJ years ago and it's a real pleasure to have the opportunity to get in front of a microphone and reach out to the public over that medium, be it on KFOG or KALW.

The next chance to meet the San Francisco Amateur Astronomers at a star party on Mt Tam is this Saturday night, July 25th. The evening opens at 8:30 pm with a lecture by Dr. Natalie Batalha of San Jose State, talking about a NASA mission called Kepler. The Kepler Mission is looking for habitable planets that are orbiting other stars in the Milky Way. After the lecture, the SFAA will have telescopes for public viewing of the heavens. Unfortunately I will miss the lecture and star party on Mt Tam this month, but fortunately I'll be near Lake Tahoe enjoying dark skies and hosting some star parties there. More on that in a future post.

22 July 2009

Total Solar Eclipse in Asia

Today a large part of the eastern hemisphere experienced a solar eclipse, and along a narrow band of Earth viewers were well positioned to experience a Total Solar Eclipse, a rare and beautiful phenomenon. Unfortunately for most, the summer weather was miserable and the skies were cloudy - something that eclipse viewers (and eclipse chasers like me) don't want. Still, there was some limited visibility from a few observing sites. The tour group organized by Sky & Telescope Magazine saw a "murky" total solar eclipse. Better than none, I suppose.

For those of you wishing to see one closer to home, you'll have to wait until 2017 for a Total Solar Eclipse in the USA.

15 July 2009

KFOG Broadcast: July 15, 2009

Moon, Pleiades, Mars and Venus

The next few mornings provide a great chance to see close alignments of planets, the Moon and the easy-to-spot, beautiful star cluster known as the Pleiades. Click on the illustration (at the right) for a detailed view of the spectacle in the eastern pre-dawn sky, especially the changing location of the Moon each morning as it wanes from last quarter to a thin crescent.

12 July 2009

SFAA Astronomy Lectures: Spitzer Telescope, Kuiper Belt

Every month the San Francisco Amateur Astronomers (SFAA) host a lecture by an expert in the field of astronomy. In June, the guest was Dr. Dana Backmann of the SOFIA Project and SETI Institute. Dr. Backmann spoke about the Spitzer Space Telescope and the detailed research underway to understand and photograph Exoplanets. These are planets orbiting stars outside of our own Sun, such as Epsilon Eridani, Fomalhaut and Vega. Of the 350 stars being studied by the Spitzer Space Telescope, 20% of them have "Kuiper Belts" where Neptune-like planets can be found.

This month the San Francisco Amateur Astronomers meeting and lecture takes place on Wednesday July 15th at 7:30 pm. The lecture features Dr. Eugene Chiang, Associate Professor of Astronomy and Earth & Planetary Science at UC Berkeley, in a talk entitled "The Tenth Planet & Beyond." Dr. Chiang will focus exclusively on the Kuiper Belt, the part of the Solar System beyond the orbit of Neptune that includes over 1000 icy, rocky objects, including one bigger than Pluto.

The SFAA lectures always take place at the Randall Museum in San Francisco and are open to all ages (although many of the topics are oriented toward an adult audience). Bring a friend and take advantage of the chance to get a truly in-depth perspective on a range of topics in the field of astronomy.

One additional note: a traveling display of astronomical photographs from space missions are on tour and currently at the California Academy of Sciences in Golden Gate Park in San Francisco. The display, called "From Earth to the Universe (FETTU)" will remain at the CAS until September and then move to the Tech Museum in San Jose. The FETTU exhibit showcases the varying spectra of light and how scientists learn by studying the universe at wavelengths of light other than the visible spectrum, something that can help the public to better understand the SOFIA Project.

08 July 2009

iPhone apps: Star Walk, Moon Map Lite

I love my iPhone. There are many reasons for this, not the least of which are the nifty astronomy apps that are available for the iPhone. These apps bring a universe of information (pun intended) to my fingertips anytime and anyplace.

I've been using these apps while enjoying the rare clear evenings here in San Francisco this summer and will start posting short write-ups of these apps. Although these are not definitive, elaborate product reviews, I wanted to offer some cursory thoughts on a selection of astronomy apps for the iPhone. Here are two, Star Walk and Moon Map (Lite).

Star Walk: ($4.99) I am delighted with this application and have put it to work under different circumstances and in different settings, high on Mt. Tam, in the coastal redwoods where the skies were dark, and in my own backyard in San Francisco under the glow of city lights. Dan Schroeder has an excellent website with a complete review of Star Walk including screenshots.

My personal experience is that the application provides the detail needed while enjoying an evening under the stars. I used it extensively to accurately locate all the stars of constellations when I simply want to know the exact configuration of Bootes or Virgo or Centaurus (as noted in my Mt. Tam blog post). I also used Star Walk with binoculars to find Messier objects in Canis Venatici and Ursa Major this evening and the level of detail was just sufficient to help me to correctly identify these objects.

As with any iPhone application, there is tremendous flexibility to zoom in and out, something that makes map reading feasible on such a small screen. Having all of this detail in my pocket, ready to go at any time, is a very powerful tool for the casual observer as well as the seasoned amateur. My test of technology, hobby toys and computer applications is whether I actually get them out and use them when I should. With Star Walk, I find I am using it more and more often to give me deeper insights into the night sky.

Moon Map Lite: This is a free application (there are standard and "pro" versions that cost a few dollars) and it does just what it claims, providing a nice detailed map of the moon that you can scroll and zoom. The creator of Moon Map has a nice webpage showing all three versions of the application with short demo videos.

Earlier this week the full moon dominated the sky and I spent some time trying to use Moon Map Lite to help me identify some of the major features of the moon. I've not tried to identify more than just a few features of the moon in the past, so I figured this would be a chance to see if I could learn some new craters and seas.

To my dismay, I found this to be considerably more challenging than expected, primarily because the full moon is illuminated in a way that "drowns out" some of the key features of craters and makes them look quite a bit different than the excellent maps in Moon Map. However, I don't blame the Moon Map application for this, but rather my limited attempt to use it during only one phase of the moon. I will try using Moon Map to learn more of the moon's features when the moon is at different points in its orbit, looking for additional details through the telescope that might be easier to see when the sunlight strikes the moon from different angles. And who knows, I might just spring for $2.99 to get Moon Map Pro :-)

Coming soon: I'll review more iPhone apps including Distant Suns, Iridium Flares, ISS Visibility and iSolarScape. If you want to read an excellent group of reviews of star-map applications and see a very helpful comparison chart, look at Dan Schroeder's webpage comparing seven different iPhone apps.

04 July 2009

International Space Station Marathon

When I host a star party or head outdoors in the evening, I like to check the status of satellites such as the Iridium communications satellites or the International Space Station (ISS). When they are visible, I like to point them out to friends. I marvel at these satellites in particular because they are (a) bright enough to see even with bright city lights, and (b) are well tracked and therefore predictable.

For the next few weeks the International Space Station will be particularly well positioned in its orbits around the Earth to be seen much more often than usual - even multiple times a day each week - throughout the month of July! I am looking forward to the graceful swing of the ISS across the sky, speeding at over 17,000 miles per hour overhead. NASA is calling this especially interesting period of time the Space Station Marathon and I think it will be great. Next week the Space Shuttle Endeavour will launch and link to the ISS to make the flyby even more interesting.

Here is the timetable for ISS visibility over San Francisco. If you don't live here, you can use the link on the right hand side of this blog to get to the general purpose ISS locator ("Space Station/Satellite Sighting").