Tuesday, March 26, 2013

Sunsets from the summit of Mt. Lemmon

Working as I do at the Mount Lemmon SkyCenter, I am often treated to sunset from the 9157 foot summit of Mt. Lemmon.  Whether it is with our guests looking for the Sun's Green Rim or simply at the end of a day doing other work it remains a special place and special time.  Here are a few of the various sunset images that I have taken over the past year.  Remember you can click each image to enlarge it.

Guests enjoying the late season snow while preparing to view the Green Rim

Beautiful Sunset portending a very stable evening of observation

Sun setting into a layer of dust in the valley
Sun having dipped below the dust layer

The shadow of Mount Lemmon rising in the east (Sun is behind me)

A view of Kitt Peak National Observatory

Shafts of light through a late summer monsoon
And of course, my favorite sunset image of the past year is the image below, taken during the June 2012 Transit of Venus.  It was taken through my TEC 140 with a Herschel Prism and shows quite a bit of atmospheric distortion...Obviously, Venus is the blob at lower left, just touching the horizon.  This is my favorite as not only had I purchased my first DSLR the week ahead of the transit, but this event will not repeated for anyone alive today.

2012 Transit of Venus Sunset

Monday, March 18, 2013

Stellarvue 90T first night

After a good morning yesterday with the Stellarvue 90T, I briefly used the telescope last night to observe the Moon, Jupiter, and the Pleiades star cluster (which is, after all, the namesake of of the observatory).  It was a beautiful night to observe all these targets naked eye, as Jupiter and the moon were within a few degrees of each other and the Pleiades were not far to the northwest.  I used the telescope (seen at left)  at low power to observe the Pleiades  and with a 35mm Panoptic eyepiece the entire cluster was nicely framed...of course this represents a magnification of 18X with a very large exit pupil meaning that I had to be careful to keep my eye centered quite a bit above the lens of the eyepiece.  I have no doubt that from a dark site on a moonless night that I would easily be able to see some of the nebulosity surrounding this cluster, using this instrument.

Still using the 35mm Panoptic, I was able to get the Moon and Jupiter in the same field of view.  Aesthetically pleasing for sure, but certainly not useful to tease out any real detail in either target.  Increasing the magnification on Jupiter to 126X (5mm eyepiece) brought out the subtle color and shading in the equatorial bands and polar regions that make Jupiter such a  lovely target.  The planet was slightly more tan in color than when observing in my larger 140mm refractor.  There was no spurious color on the planets limb, which was a good sign.  Below is a shot I took with my Canon T2i.  It was 1/50 of a second at ISO 100.  I was using a non-tracking mount, but did use the mirror lock feature of the camera along with a 2 second delay on the shutter release.  Jupiter is at the upper right...click to enlarge.

After observing the moon at various magnifications, I then took a picture of the moon, using a very cheap 2x barlow lens.  This image was 1/13 of a second, also at ISO 100.  Click the image to enlarge.

Sunday, March 17, 2013

Solar Stellarvue 90T

A couple years ago I owned a very nice 90mm triplet refractor from Stellarvue, which I had sold to pay for some other astronomy gear.  Recently, after trying other small aperture scopes, I decided that I wanted to purchase another one of these fine refractors.  At 90mm, the scope is a terrific size to take anywhere, and also has a bit more light gathering than the 80mm telescopes that dominate the small scope market. Additionally I wanted a telescope to use for white light solar observing that would compliment my Lunt 60mm HA without creating balance headaches when used simultaneously.  As it happened, Stellarvue had on their website a used SV 90T, with a carbon fiber tube and a very nice feathertouch focuser.  While one pays a slight premium buying used from Stellarvue as opposed to a private individual, Stellarvue does warranty their used telescopes for two years, just as they do with a new instrument.  To sweeten the deal, they also included a very nice, new soft-sided case with room for much more than just the telescope.  After a few days deliberation, I contacted Stellarvue and ordered the telescope.  It arrived in less than 48 hours, along with wind, dust and scattered clouds...typical with a new telescope, and quite frustrating after a week of clear steady night time skies that define the desert southwest!

While I have not yet had a chance to really shake down the telescope at night (other than point it at a few bright targets like Jupiter and the moon last night) I did have an extensive solar session with it this morning.  All in all, it provides exactly the view of the Sun I was expecting- sharp and detailed when used with my Lunt Solar Systems Herschel Prism.  I am fortunate to have a TEC 140 and compared to that telescope, the SV 90T definitely shows slight color on the limb of the Sun.  There is a very thin blue-green ring along the limb of the Sun, regardless of eyepiece used.  It is not in any way obtrusive and had I not been looking specifically for this color, I may not have noticed it.

Below is a sketch I made of the Sun, completed at 1631 UT 3.17.2013.  Although hard to note in my scan of my sketch, the 90T revealed very fine detail in spot regions, brighter facula surrounding regions near the limb, as well as hinting at granulaton in moments of very steady seeing.

So far, I am quite pleased with this small refractor.  It is light weight and delivers all the detail I expected given the 90mm aperture.  Below you can see my initial attempt at piggybacking my Lunt 60mm HA solar telescope on the SV90T.  It is likely not my final piggyback solution, but it was an exceptional experience being able to go back and forth between images.  Together, these telescopes and required accessories weigh  less than 20 lbs, and likely closer to 15.

Thursday, March 14, 2013

Comet Pan-STARRS

Comet C/2011 L4 Pan-STARRS has been all the talk among the amateur astronomy crowd these last few months.  While mostly putting on a show for our southern hemisphere friends, this bright comet did make a brief appearance this week in the northern hemisphere just following its close approach to the Sun on March 10th.  I spent the early part of the week camping and stargazing at Rancho De Farrar in Portal, AZ which will be the subject of the next post so missed the first few opportunities to observe this comet.

Last night I was leading a program at the Mount Lemmon SkyCenter so I had a great view of the comet with our guests- many of whom had never observed a comet before.  I tried to capture some pictures of the comet while entertaining our guests, and the image at left is one of the better ones.  You can see immediately below the comet, the planet Uranus...if you want to see it labelled, click on the thumbnail image at right.  This image was captured with my Canon T2i and a 300mm lens at F4.  It is a 2 second exposure at ISO 400.

Tonight, after a long day at work, I climbed onto our roof to try and get one last look at the comet.  It is quickly descending into the twilight and it is likely that tomorrow night the comet will be very close to the horizon by the time it would be dark enough to be visible in binoculars.  I found the comet when it was about 10 - 12 degrees above the horizon and again captured a few images.  The picture below was taken with the same camera, but this time with a lens at 200mm at F4. It is a 2 second exposure at ISO 1600.

Monday, March 4, 2013

Gone Caving...

In what seems like another lifetime, I used to do a bit of caving throughout southern Arizona.  The area is known for world class caves and if one is motivated and willing to invest the time, one can experience environments that are as unique as any on the planet.  The conservation ethic is quite strong among cavers as by their very nature these underground environments are extremely vulnerable to alteration and damage.  Descending below ground one literally steps into geologic time- and the Earth does not always act quickly.

I have not done much caving in the last few years due to several factors, among them my closest caving buddy has moved on to other adventures...further, I was never really connected with a local caving group, such as the Escabrosa Grotto.  Caving is best done in groups; not only for safety but there are always cavers with more and less experience than yourself and when in an underground environment you always have something to teach and something to learn.  Groups such as the Escabrosa Grotto do a marvelous job of supporting the USFS and other entities toward the ultimate goal of protecting these natural wonders.  I have been on 12-14 hour excursions into caves and assisted with everything from surveying, to restoration, to bat studies...but I digress.

Friday, after a particularly tough week, Ian and I hatched a plan to revisit a non-gated cave in the Santa Rita Mountains.  It is a cave particularly well suited for young cavers, or as a first experience for someone who is unsure of their comfort level in a cave.  While it does not have a tremendous amount of cave features (due to nature, overuse and the fact that it is not gated), it is still a worthy introduction to caving.  At right, you can click on the image for a close up view of the stalactites and other features seen in the image above.

Tight squeezes, crawling, mud and even a few insects were experienced during the two hours we spent exploring the cave.  Ian invited his friend Tyler who had never been in a cave like this and Tyler had a great attitude as he explored beyond his comfort zone.  I have three rules in the outdoors:  Be safe, have fun, and learn a little.  I think we succeeded on all three fronts as evidenced by the pictures of our happy little caving group.  All images were taken with my Canon T2i and a 40mm lens.  As always, click the images to enlarge them:

Beth in the hole!
Ian in the hole!

Tyler in the hole!
Lunch break