Saturday, June 25, 2011

Fun in the sun

Fried egg on sidewalk
Summer is here in Tucson....last night I was in my observatory at 10:00 PM and the temperature (albeit on my phone!) read 96 degrees F.  I was actually sweating while observing globular many of you can claim that feat?!?

Today it is predicted to be around 100 degrees by lunch and approaching 108 in the mid-afternoon..."but it's a dry heat"...Yeah...Right.  Whoever originated that comment was either severely arthritic or delirious from heat stroke.  I've been to Houston and spent over a dozen summer vacations in North Carolina.  Humidity is oppressive no doubt, but 110 in the shade is more than an expression, it's HOT!

Regardless, I decided that my solar observing itch needed to be scratched this morning, so I dutifully got out of bed at 0600 local time and set up the telescope.  Two hours later, I was out observing El Sol and feeling somewhat closer to her than usual as I worked to keep the dripping sweat from landing in the eyepiece or on my sketching clipboard. Despite the inferno, the seeing conditions were actually quite steady as the high pressure system that has settled over Arizona has created a bubble of steady air over much of the southern portion of the state.  I completed the sketch below at 1507 UT (8:07 AM MST) using my Lunt 60mm dedicated Hydrogen Alpha Telescope.  The image is from the Solar Dynamics Observatory's Atmospheric Imaging Assembly at 1259 UT, about 2 hours prior to my sketch.  Click on either to enlarge them.

As you can see, there are five active regions on that face of the sun, however, none of them are as impressive visually as what the SDO image would imply.  Region 11236 which is rotating off the west limb is certainly the brightest region and contains a couple spots visible in HA.  AR 11242 was also interesting in that it appears to be dividing and each side contains a small spot.  The most exciting features of the day were the very bright prominences on the northeast and southwest limbs.  The large on on the northeast was growing rapidly during the time of my sketch, and it will be interesting to watch this throughout the morning.

Wednesday, June 8, 2011

Solar storm

If you follow this blog at all, you know that I am an avid solar observer - and yesterday the Solar Dynamics Observatory captured a massive eruption on the sun.  According to the mission blog "The Sun unleashed an M-2 (medium-sized) solar flare with a spectacular coronal mass ejection (CME) on June 7. The large cloud of particles mushroomed up and fell back down looking as if it covered an area of almost half the solar surface.

SDO observed the flare's peak at 1:41 AM ET. SDO recorded these images in extreme ultraviolet light and they show a very large explosion of cool gas. It is somewhat unique because at many places in the eruption there seems to be even cooler material -- at temperatures less than 80,000K.

When viewed in SOHO's coronagraphs, the event shows bright plasma and high-energy particles roaring from the Sun. This Earth-directed CME is moving at 1400 km/s according to NASA models. Due to its angle, however, effects on Earth should be fairly small. Nevertheless, it may generate space weather effects here on Earth in a few days."  This video is unlike any that has previously been recorded:

Monday, June 6, 2011

On dark skies, family, friends, and telescopes...Life is good

The title says it all...dark skies, my lovely family, good friends and great telescopes.  Life my faithful readers, is good.  Despite my total slacking off from maintaining the blog, I have continued to have some excellent astronomical adventures, including a trip this past weekend to a site in northern Arizona that is frequently referred to as Frederickson Meadow.  The meadow was named in memory of longtime Saguaro Astronomy Club member Dave Frederickson, and it is a well deserved name.  The meadow is quite beautiful and provides expansive views of the sky.  In addition to my family, I travelled to the meadow with my friend Jerry Farrar to spend the weekend observing.  As luck would have it, there was a group of about a dozen astronomers from the Phoenix area who quickly welcomed us to their star party.

The meadow is situated roughly between Flagstaff and Payson and is approximately a 4.5 hour drive from Tucson, with only the last 5 miles on a well maintained dirt road.  As soon as one sees the Discovery Channel Telescope situated on the next ridge, one knows that the sight is likely very good for astronomy.

Most folks camp in the trees on the north side of the meadow, and the Forest Service has requested that we not drive into the meadow itself.  This makes great sense as it preserves the meadow and allows many grasses and wildflowers to flourish.  For our night time observations, I had taken along my TEC 140 refractor and Jerry brought along his 12 inch SCT as these scopes are quite complimentary when parked alongside each other.  Below, you can see Jerry observing the sun through his dedicated hydrogen alpha telescope which he also brought on the trip.

Each day brought very stiff breezes, which I would estimate between 10 and 20 mph, with occasional gusts closer to 30 mph.  As if on cue, these winds would vanish at sunset and start up at sunrise...(perhaps the late Mr. Fredrickson was taking care of us).  These breezes kept the daytime temps comfortable in the low 80's, however, the nights were much colder with Thursday night in mid-20's and Friday and Saturday nights in the mid-30's!  Certainly a reprieve from the June desert heat.

One of the nice things about the meadow, is that one can choose to spend time in cool shade of the pines reading, napping, snacking, planning your nights observing run, or whatever strikes your fancy.  If one is after a bit more activity, it is a great area for an easy walk around, a more strenuous hike, or a game of nerf football.  Nearby, about 30 minutes back up the road, there is even an RV resort where one can grab a bite to eat or take a shower ($5).  Of course, we were there to observe and I am sure that at this point you are wondering when I will get to the point, and tell you about the observations we made...but before I get to that, take a look at the "Great Comet of Frederickson meadow" alongside the crescent moon just after sunset.

Click the image to see the supernova!
Those of you who are amateur astronomers know that on Friday it was widely reported that a supernova had erupted in one of the arms of the whirlpool galaxy, M51.  French Observer Stephan Lamotte Bailey, created the image at left...Click on it and you will then see the animation which blinks the supernova in and out.  This was the talk of the group as the sun was setting Friday evening, and nearly every scope and camera in the meadow was targeting the grand galaxy.  I first attempted to spot it in my TEC 140mm APO, and with a bit of patience it was clearly there with averted vision, reminiscent of observing a challenging central star in a planetary nebula.  Jerry took a look and was also seeing the same star.  Naturally, we then went over to his 12 inch SCT and the supernova was clearly visible with direct vision, as an approximately 13th to 14th magnitude star.  What is so neat about this, is the fact that we were observing an extragalactic star....which is not something one does every day!

The main reason I brought along the refractor on this trip was that I had limited space, and this was the first chance that I had this year to spend extended time sweeping through the milky way...and the high contrast wide field TEC 140 is a world class instrument practically made for this purpose.  The scope garnered high praise from all who looked through it; which in this case was a group of very experienced amateurs who appreciated the nearly 3 dimensional views that the scope provides.  Whether it was Saturn at 300X, Omega Centauri and globular star clusters in Ophiuchus and Sagittarius, planetary nebula, or dark nebula, everyone commented on that sharpness and contrast of the TEC 140. In addition to having my fun with the bright Messier objects and generally sweeping around the milky way, I also observed some galaxies- mostly in Canes Venatici and Coma Berenices.  This may seem crazy with only 5.5 inches of aperture, but being able to see them in a wide field setting adds a context that is missing when observing them in my 12 inch SCT.  This post is getting long, so I will only share some of my favorites from these constellations below:

Hickson 68, a galaxy group composed of NGC's 5353, 5354, 5350, 5355, and 5358 (in order of magnitude from brightest to faintest...a to e in the image at left).  All five of these galaxies were visible in the refractor, despite the presence of a magnitude 6.5 star only 3 arc minutes away.  It is a very pretty grouping of galaxies with the brightest members shining at magnitude 11.5 and the faintest, tiny little NGC 5358 at magnitude 13.6.   I would highly recommend this target if you are interested in galaxy groups as each of the members is distinct.

NGC 4244 is a popular target due being large and bright, and is also known as Caldwell 26.  It is an edge on galaxy, and at high power, the TEC revealed some of the galaxies mottling as well as a distinctly bright nucleus.  The galaxy is nicely pinned down by stars off each end. 

NGC 4217 is a another elongated galaxy but is much more difficult to see, requiring averted vision.  While listed at magnitude 11.2, it has a surface brightness of around magnitude 13 and it shares the field with three 9th or 10th magnitude stars whose light interferes with seeing the galaxy.  Most interesting is that this galaxy is often overlooked as it is overwhelmed by its neighbor and possible companion M106.  At 75x, both of these galaxies were visible in the eyepiece. 4217 is the edge on galaxy in the lower right of the image.

NGC 4298 and 4302 make a beautiful, ghostly pair in the TEC.  4298 is a diffuse glow with no discernible nucleus, and 4302 is a thin edge on galaxy, also without detail.  These galaxies sit quite close to each other in the eyepiece, perhaps only 2 or 3 arcminutes apart. It is easier to hold 4298 with direct vision, even though it is only .3 magnitudes brighter at 11.3 versus 11.6
I did observe some other areas of the sky, including NGC 5128, the Centauraus A galaxy.  This has long been a favorite target of mine for the wealth of detail visible in the hamburger like galaxy.  Unfortunately, this galaxy was sitting in the Phoenix light dome (yes, there is a light dome despite being 100 miles+ away) and the amount of detail was not as great as I have seen at other locations.  If you are interested, the phoenix light dome is about 15 degrees high on the southern horizon and spans about 15 degrees in azimuth.  Even though this area is not free from the light dome, it is overall the second best site I have been to in Arizona for observing, with Portal being the first.  Overhead, 7th magnitude stars are visible and the setting is is delightful. I'll be heading back next new moon, weather permitting!