Astro Bob A look at celestial happenings in the Northland and beyond Bob King View my profile Click here to view previous posts or additional resources

Comet goes a courtin'

The comet K5 McNaught is the blue-green cloud with the bright central nucleus below center. NGC 6946 (at left) is 10 million light years in the background while the star cluster NGC 6939 is in our galaxy the Milky Way and 5,800 light years away. Credit: Michael Jaeger

Since comets are some of my favorite solar sytem residents to study and observe, I subscribe to several different online lists populated by similar-minded people. This weekend Michael Jaeger of Austria photographed the current brightest comet in the sky, C/2009 K5 (McNaught) in the constellation Cepheus the King. It's around 8th magnitude and just visible in a big pair of binoculars from a dark sky site. Yesterday the comet passed near the spiral galaxy NGC 6946 and star cluster NGC 6939. For a time, all three sky objects occupied the same small circle of view forming a trio of cosmic diversity.

Comets never linger. Already K5 McNaught has crept further north en route to its next rendevous. Happily, Jaeger was there with scope and camera to capture a striking image of a brief but beautiful encounter. If you're interested in comets and want to keep up with news and the latest photos, here's the link to subscribe to the comet images and comets-ml groups.

I got up this morning around 4 and peeked out the window for a moment before going back to bed. Whoa! What was that bright star? In a second I saw it move and realized it was the International Space Station (ISS) filled with sleeping astronauts. We have another full week of ISS passes coming up, so if you haven't see the space station or just enjoy tracking it, here's when to look for the Duluth region. For times for your town, click HERE and fill in your zip code. What's interesting about the current round of passes is that the ISS transitions from morning to evening passes with no gap in between.

* Tuesday morning April 27 starting at 4:29 a.m. Bright pass across the southern sky.

*Weds. April 28 at 4:56 a.m. A brief, low pass across the south. Again at 9:21 p.m. crossing the southern sky.

* Thurs. April 29 at 9:46 p.m. Brilliant pass high in the south!

* Friday April 30 at 8:36 p.m. from southwest to east. Again at 10:11 p.m., a brilliant pass high in the north.

* Sat. May 1 at 9:01 p.m. Brilliant pass high across the south. Second pass at 10:37 p.m. across the northern sky.

The sky should be clear for the region tonight with the moon approaching full. Look to its left to see Virgo's brightest star Spica. Created with Stellarium

The moon's near Spica, a Latin name from "spicum" which signifies an ear of wheat held in the hand of Virgo the Virgin. Although Spica might have to compete with the moon for your attention it's a formidable star. Lying 260 light years away, Spica is a blue giant seven times the diameter of the sun and over 12,000 times brighter. Although no telescope can see it, Spica has a very close blue companion star 3 1/2 times the size of the sun that completes an orbit in just four days. At 11.2 million miles from Spica, it's less than three times Mercury's average distance from the sun. That's tight! Scientists can "see" stars around other stars even when they're too close to separate with a telescope by using a spectrograph, an instrument that detects the light contributed by each object as they orbit about one another.

Spica fascinates in another way: being 10.5 times more massive than the sun, it's heavy enough to possibly explode one day as a supernova. That'll give the tonight's bright moon a run for its money.

Posted by: rking@duluthnews.com on 4/26/2010 at 9:15 AM | Comments (0) | Permalink | Edit

Tags: daily updates, c/2009 k5 mcnaught, space station, astro bob, blogs, life, comet, iss, moon, spica, supernova