Venus is becoming visible

Venus is becoming more easily visible after sunset. The image above, taken from my apartment's balcony, shows this brilliant planet glittering through the tree limbs. As our sister planet continues to emerge from behind the Sun, it will become increasingly bright and more easily seen. Its elongation (angular separation) from the Sun will increase for several weeks, shining brightly in the post-sunset evening. You can use this Solar System Simulator from NASA to see what relative positions the planets in our solar system are in to cause the changes in Venus' position from night to night.

Asteroid Flyover

Headlines were in abundance early this week about the flyover of the asteroid 2005 YU55, whose orbital path around the Sun took it inside the orbit of the Moon on Tuesday night (eg. see this article from Yahoo! News). This asteroid made a close pass by the Earth, being just 201,000 miles away. The asteroid was in no danger of hitting Earth, which NASA officials were quick to point out, but the fact that a 400-meter asteroid might come so close was enough to remind us all that a bad day is just one asteroid away. Having the opportunity to see an asteroid (or anything that's not man-made) move noticeably through the sky was enough to send me up to the observatory for a look.

I went up with two students, and a few folks from the public showed up as well. Using the 16" telescope we were able to identify the asteroid and track its motion across the sky for a couple of hours. Looking through the eyepiece, which had a field of view of about 1/2 a degree, the asteroid was moving quickly. Its motion with respect to the stationary stars was imperceptible until you saw it, at which point you couldn't NOT notice it moving. While it was not particularly bright, everyone present was able to see it. I was quite surprised at how rapidly it moved. I'm accustomed to seeing asteroids on CCD images make small streaks against the stars as they move across the CCD field of view, but seeing an object moving this rapidly (at its fastest it was moving at about 16 Moon-widths per hour) made quite an impression.

We attempted to take some images of it but experienced some trouble with the equipment. The CCD camera we were using was not one I had used before and we had difficulty identifying the field of view on the computer screen - it was smaller than the eyepiece. While we were unable to get any images of the asteroid, some had better luck. You can bet I'll be better prepared the next time something large flies by! By then perhaps we'll have the 1-meter telescope up and running for some real viewing.

For those who are privileged to see a beautiful sunset on the western horizon, keep your eyes peeled in the fading orange for a bright point of light above where the sun fell below the horizon. This bright point of light is Venus, our sister planet finally reappearing from behind the Sun. The eagle-eyed viewer might even see Mercury just next to Venus, although Mercury's brightness is quite a bit dimmer. For the next week, both planets move away from the Sun, being visible for longer and longer after sunset. After November 14, Mercury begins to move back toward the Sun, while Venus continues on in its wider orbit. The next time you have a clear view of the sunset, take a peek and see if you can spot both planets!

Large Sunspot 1339

Moving across the face of the Sun right now is a massive sunspot, given the innocuous name "Sunspot 1339." This sunspot is approximately 17 times the size of the Earth and harbors the strong magnetic fields that are capable of producing X-class solar flares - the type that generate brilliant northern lights on Earth and sometimes threaten satellites in orbit. Viewing this through the little 4.5-inch telescope I have here using a solar filter, I took a picture of it by holding my digital camera up to the eyepiece:

Though it's a bit blurry (the camera autofocuses and I couldn't get it any better without owning a digital SLR), the massive sunspot group is clearly visible. Compare this to the image on www.spaceweather.com.

I came across a small color CCD camera made by Meade among the equipment up at the observatory and decided that it might be light enough to test out on this small telescope. However, it has been a struggle to get it to produce sharp images and without the ability to track an object steadily the target continually moves through the field of view. Jupiter's moons were clearly visible through the telescope but no image could be taken where the points of light weren't stretched into streaks. However, I did get a decent image of the Moon:

Short post today. After all...it's the weekend :-)