Globular Cluster Messier 14

For amateur astronomers, spring may be galaxy observing season, yet summer provides the opportunity to observe most of the globular clusters that inhabit the outer halo of our galaxy.  Globular clusters are to me, the most beautiful objects to observe through a telescope as they are tight swarms of stars- containing well over 100,000 stars (and some many more!) all within an apparent diameter of a few arc-minutes.  Many folks describe them as diamonds spilled on black velvet and that description is apt.  At left is an image I took of the large globular cluster M 22 in Sagittarius last summer with my Canon T2i through my TEC 140.  (It is a single exposure, not multiple exposures integrated)

These clusters are tightly bound by gravity which gives them a general spherical shape and a higher density of stars toward the center.  There are upwards of 150 known globular clusters in our Milky Way galaxy. While they contain some of the oldest stars in the Universe, the origin and role of globular clusters in the evolution of galaxies remains unclear and this is an area of active research.   Astronomers who study galactic evolution have been able to detect globular clusters in most of the galaxies they have studied, and some galaxies contain extraordinary numbers. For instance, the great Andromeda Galaxy has more than 500, and the giant elliptical galaxy M 87 in Virgo contains approximately 13,000!  (See this post for my observation of the jet emanating from the center of M 87).

Last night I was out observing and spent quite a bit of time observing globular clusters in the constellation of Ophiuchus.  There are 20 reasonably bright globular clusters in this constellation, most if not all of which should be visible in my 140mm refractor under reasonably dark skies.  Among these globulars are 7 Messier objects, from M 107 which is the dimmest of the Messier globular clusters to the majestic clusters M 10 and M 12.  After observing these, as well as M 62, M 9 and M 19, I slewed the telescope to M 14 and was surprised at what I saw.

I have observed all of the Messier objects at some point years ago, yet  I am not sure that I have returned to this cluster since that time.  The cluster, discovered by Messier in 1764, lies in a remote area of the constellation and at first glance the cluster is unimpressive.  It is difficult to resolve many stars and appears more nebulous than cluster like...which is probably why it did not stick in my memory as a great visual target.  More experienced now than I was those years ago, I began to wonder why this cluster appeared so large and reasonably bright in my telescope yet resolution of the stars was so difficult.  A little reference checking and I learned that this globular contains several hundred thousand stars and has an absolute luminosity about 400,000 times that of our own sun!  This cluster is about 30,000 light years away, and as it turns out, the light from the cluster is obscured by an extensive amount of dust in our galaxy.  Below is my sketch from last night of M 14 at a magnification of 163x.

The cluster has a brighter central region with a fainter outer halo and it is difficult to resolve member stars (the sketch is generous in this regard).  The cluster has a grainy appearance and with averted vision it does seem that some faint stars come and go.  The cluster is approximately magnitude 7.6 and has an apparent diameter of 11 arc minutes.  Again, with a cluster this large and bright one would expect to resolve stars.   Often, it is not simply the aesthetics of objects in the eyepiece that make an observation interesting; it is knowing what it is that one is looking at.  In this case, one of the most impressive facts about this cluster is that it has a diameter of approximately 110 light years.  Our galaxy is approximately 100,000 light years across, so it would take only 1000 of these clusters to span the galaxy.  that may not sound impressive until one considers that our galaxy has between 200 and 300 billion stars...

Planetary conjunctions!

Today I returned from LA to the comfy confines of Tucson and my observatory.  As the sun was setting and I was noting the beautiful colors in the Belt of Venus I was reminded of how lucky I am to live in an area with such open horizons and frequently clear atmosphere.   The evening was so nice I decided to take a picture of the planetary conjunction in the west  from my home so as to capture many of the colors in the sky that I could simply not capture from the middle of LA.  The image below was taken at 8:13 MST (0313 UT) with my canon T2i and a 24-105mm zoom lens at 88mm.  The image was .8/sec, ISO 200 at f/4.5.  Click on the images to enlarge them and if your browser automatically re-sizes images you may need to click them a second time.  The images are identical with the exception of the labels on the right hand image.

As it happens, I discovered on my cameras memory card another conjunction image that I had taken earlier in the month, on May 13th at 0332 UT when the Moon was very close to Jupiter.  Jupiter is the bright dot near the lower right of the image (click to enlarge):

This was a 1 second exposure at f/4 with a Canon 15-85mm EF-S lens set at 85mm, at an ISO of 400.  I am quite happy with the exposure on the moon, particularly in that one can appreciate not only the Earthshine, but also some of the detail on the lunar terminator.  For instance you can see how some of the crater floors are not yet illuminated by the rising Sun, resulting in a scalloped look to the bright terminator.  Below is a full resolution crop of the moon from the above image...as always, click to enlarge.

Good night moon!

Planetary conjuntion

The nice thing about looking up at the planets in our sky is that they are bright!  Even here in suburban Los Angeles, the planetary conjunction that is gracing our evening skies is easily visible.  I am staying just off Ventura Boulevard (which sounds much nicer when put to music) and last night my niece Sophie and I went out to try and find a spot where we could spot the planets between the buildings and trees.  We managed to find the bright planets pretty easily and the palm trees in the image below were the best we could do for interesting foreground objects.

The brightest planet closest to the horizon is Venus, with Jupiter at its upper left and Mercury at its upper right.  Over the next couple nights Venus and Jupiter will appear closer together.  We also observed Saturn in the eastern sky and Sophie pointed out that we had just seen 5 of the 8 planets in our solar system (don't forget Earth!).

The picture was taken using a 24-105mm zoom lens (at 105mm) for 1/6 of a second handheld at f/5 with an ISO of 100.  I used Photoshop for some contrast and to sharpen slightly.  Tonight I will be at the Dodgers-Angels game and if it works out perhaps I will get a nice shot of this alignment from Dodger Stadium...

The Beach

Ian and I are in Los Angeles hanging out with my niece and nephew for the weekend while my sister and her husband are off celebrating their 10th wedding anniversary.  We had a great time yesterday at the beach and today's post features my first guest blogger ever, my niece, Sophie.









The beach!

The waves are wild!  Everybody falls down at least ten times.  I scrape my knees in three different places.

Evan wants five cokes!  He slurps them up in four sips.  Sounds delicious

I got buried in sand by my cousin and uncle.  I got buried sooooooo tight that I could barely breathe!  My cousin even stepped on me!

Evan got buried in a hole that is three “feet” deep!  He is even standing in it!

I am swimming with my cousin Ian.  Does Ian like it?  Is it too cold?

People were flying kites!  It was windy.  It was a perfect day to fly kites. Dog kites,  Princess  kites and butterfly kites!

Evan surfs on the sand as the waves pull him back. Its sand surfing!

This was our trip at the beach!

By Sophie Hummel 

Graduation time

This week is one of great excitement as Ian and my nieces Cheyenne and Cierra are all graduating from their respective schools and moving on up.  Ian and Cierra are being promoted from the 8th grade, and Cheyenne is graduating high school.  In the fall she will be attending Northern Arizona University on a full academic scholarship!  It will be a week full of small and large celebrations for these three and it all began last night with a small surprise party at our house for Cheyenne.  Below is a slideshow of images- and you can click on the slideshow to be taken directly to the album.

Mothers Day Sun

Happy Mother's Day to all the moms out there, especially the ones for whom I am about to prepare brunch: My favorite super saucy spouse - Beth; and of course our own Mom's Lynne and Wanda.

I awoke this morning much earlier than the family and set up my Stellarvue 90mm refractor to observe the Sun in white light. Seeing was quite good with only a gentle breeze and numerous spots.  I brewed some coffee, grabbed my pencil and clipboard and headed out to make a sketch of the Mothers Day Sun...and much to my surprise in the 15 minutes I was inside the gentle breeze had become 10-15 mph gusts!  Needless to say, this made sketching difficult.  Below is my sketch completed at 1500 UT (8:00 Am MST).

At the time of my sketch, the Sun was at an altitude of 31 degrees and an azimuth of 87 degrees.  We are in Carrington rotation 2136, and the Official NOAA sunspot number for today is 145.

Naked eye sunspots

If you live in the Tucson area you know that the extremely high winds of the past couple days have resulted in a quite a layer of dust here in Tucson, and last night I observed Sunset from the summit of Mt. Lemmon through the layer of heavy dust in the valley below.  I was up at the Mount Lemmon SkyCenter conducting an evening observing program for a group of local 6th graders, and due to the thick dust we were able to observe a naked eye spot group on the Sun as it set, without optical aid.   It is surprising to some, but the earliest written records of sunspot observations come from Chinese astronomers who would view spots through fog or dust at Sunrise or Sunset...as long ago as 800 BC!

I recently purchased a canon 24-105mm F4 lens, and took the images below with this lens on my Canon T2i.  This is what the Sun looked like setting in the dust...click to enlarge:

Below is a crop of the Sun at full resolution.  Click it to enlarge it to full size (you may have to click it twice if your browser automatically re-sizes images) and you can see the spot group on the upper left that the students noticed.

Finally, I captured this image of one of the students looking at Jupiter through the 20-inch Jamieson Telescope.  It was a 1 second exposure, ISO 400, at the 24mm setting, handheld...As you can see, I am pretty happy with this new lens.  It focuses quickly and accurately and the color rendition is beautiful.