Anatomy of a sunspot

Yesterday I was observing the Sun around mid-day and was quite surprised at how steady the atmosphere was.  With temperatures steadily climbing into the upper 80's and a slight breeze I had expected average conditions.  Instead, I was able to push the magnification on my scope to approximately 140X, allowing for a critical observation of the Sun in white light- this is unusal as the best observing is usually shortly after sunrise before the atmosphere has substantially warmed up.

To observe the sun in white light, I am using my TEC 140 APO along with a Lunt Solar Systems Herschel Wedge.  This combination allows for observation of the chromosphere - which is the outer layer of the Sun.  It is sometimes referred to as the surface of the star, however, this is not really accurate as the chromosphere is simply a layer of gas, and does not have a surface to speak of.  This is the layer of the sun that, if it were safe to look directly at the sun (and it is not!), would appear to the eye.  The Herschel wedge, along with a neutral density filter (akin to the glass in a welders helmet) and a polarizing filter on the eyepiece allow for observation of granulation, faculae, and sunspots.

As a result of the very calm atmosphere, I was able to make a fairly detailed sketch of the main spot associated with active region 11057 which is currently on the face of the sun.  The dark central portion of the spot is called the umbra, and the gray area surrounding the umbra is called the penumbra.  Notice the radial structure of the penumbra.  These penumbral filaments, are carrying material out from the sunspot at velocities of a few thousand meters per second! In terms of size, the central umbral region of the spot is probably in the neighborhood of 3-5 earth diameters...pretty impressive no?  Sunspots are cooler than the surrounding areas and while they appear dark against the extrememly bright face of the sun, they are actually quite radiant themselves and were they not set in front of the sun would be bright sources of light.

This is a beautiful image of the sunspot taken near the time of my sketch.  The picture was taken by Stephen Ramsden of Atlanta, Georgia who is a NASA Solar System Ambassador and accomplished solar observer.  The picture also reveals the solar granulation.  The solar granules are pockets of hot gas rising in the solar atmosphere.  When these bubbles get high enough, they relase energy through radiation, cool, and sink back down along the dark and irregular honeycomb lines.  The granulation pattern is quite random and changes quickly with individual bubbles appearing a dissapearing within minutes.

Solar activity 27 March, 2010

This past week has not afforded much chance for observing.  Between work, weather, little league and my birthday, it has been busy!  The good news is that I survived turning 41, and Ian's little league team the Diamond Jaxx are 2-0.  Ian is playing great in the infield and his bat came alive in the last game where he went 2 for 3 with two doubles and four RBI's!

I made two quick observations of the sun this morning, despite a rather turbulent atmosphere.  Throughout the observing time, the sun looked like it was boiling, and the moments of steady seeing were fleeting.  Sketches were completed this morning between 1630 and 1705 UT (9:30 and 10:05 MST).  I updated my computers scanning software, and these scans are not of great quality:

The highlight is Active Region 11057 which shows some very dark spots in both Hydrogen Alpha (Ha) and white light.  In Ha (the left sketch), AR 11057 has a strong magnetic field as evidenced by the many curving field lines emanating from the area.  There are several dark "eyelash" shaped fibrils within this region.  Active region 11058 is in the northwest and is mostly unremarkable.  It does have a distinct 'V' shave to it.

In HA, there is another large area of weak activity in the southwest, where two long, thin filaments are observed in the midst of this activity.  There is also a large and dark spot visible in both HA and white light (the right sketch) on the east limb.  In white light some facula is seen associated with this spot - yet this region is not yet designated with a number.

Solar report ~ First day of spring

Spring has sprung in the desert!  There are many wildflowers on the roadsides, and even the normally dry Rillito, Tanque Verde, and other creeks continue to flow from all the winter rains and mountain snows.  Ian's little league team, the Diamond Jaxx, have their first game tomorrow night!  To honor the start of spring, I repainted the exterior of the Lost Pleiad Observatory yesterday.

This morning dawned with crystal clear skies and quite a stable atmosphere.  I had about an hour to observe and sketch the sun so I set up my hydrogen alpha solar telescope to see what was up.  While the large prominences of the last week have dissappeared, there were still many features to be seen.  Active region 11056 shows some nice field lines both within and around the region.  While I was sketching, the region did brighten slightly, although not enough to be considered flaring.  There are two distinct filaments within the region.  Overall, there are many filaments on the suns disc today, with the strongest in the southeast.  Additionally, it appears that while not yet designated, there is an active region that has come around the east limb.  Finally, there was a small but nice and bright filaprom in the southeast.  The sketch was completed at 1540 universal time, under steady skies.

Since I still had a few minutes, I decided to take a look at the sun in white light, using my 140mm refractor equipped with the Lunt Solar Systems Herschel Wedge.  To my delight, AR 11056 revealed a few spots as well as several more pores.  There were some facula on the west limb, with the one to the northwest possibly being associated with AR 11054 which has just rotated behind the limb.  To the southeast, there was quite a bit of facula, and also a very dark but small spot.  This can be seen in the sketch to be in the same location as the as of yet undesignated active region visible in the hydrogen alpha sketch above.  The sketch was completed at 1600 univeral time (9 AM MST).

All Arizona Messier Marathon 2010

Every year during the new moon weekend in March, amateur astronomers gather around the world to do the Messier Marathon.  Arizona is no exception and we are fortunate that the Saguaro Astronomy Club in Phoenix coordinates this wonderful event.  It is held yearly at Farnsworth Ranch south of Arizona City and can draw several hundred astronomers.  Essentially, the marathon entails hunting down all 110 objects cataloged by French comet hunter Charles Messier in the early 1800's.  The March new moon provides the best opportunity to see all of the objects in one night.  This was the third year that I have attended the marathon with my very good friend Jerry Farrar.  Other than that first year where I observed 102 objects, I mostly spend my time getting to know other amateurs and observing some targets that I may not be able to see as well from the Lost Pleiad Observatory.  Take a look at the picture to the left and you will see Venus riding high above the horizon as the sun set on Friday night.  To the right, are my telescopes cooling down for the evening observing run.

Having recently read Sue French's column on deep sky observing in Lynx, I had decided to utilize my Celestron 9.25 inch SCT to observe some of the targets she reviewed in her column in the March issue of Sky and Telescope magazine, including:

NGC 4236 ~ at 7 million light years away, this magnitude 9.9 galaxy spans 22 arcminutes and as a result is quite faint in the eyepiece.   There was no discernible core, however, the galaxy is quite elongated and there are many faint stars in the field of view making for a very pretty sight.

NGC 2419 ~ More commonly known as the "intergalactic wanderer", this globular cluster is 300,000 light years away!  Despite the distance, it spans 4.1 arc minutes and appears as a mottled patch in an attractive star field.

NGC 2782 ~ This is a small and round galaxy, with a bright core and diffuse halo.  It is approximately 10 million light years distant and is magnitude 11.3.

NGC 2683 ~ Clearly the show stopper for me, I decided to sketch this magnitude 9.6 edge on galaxy.  At 11 million light years away, this galaxy appears with an extremely bright core and long thin extensions.  The sketch was made with black pencil on white paper and I scanned and inverted it to provide an image closer to what I saw at the eyepiece.

At this point, I wandered around a bit to see what others were up to, and to find myself a nice large dobsonian owner (large scope, not large owner) who wanted to share some views.  I ran into my new friend Kevin who has a 16 inch dob, and he showed me the "Horsehead Nebula" through his scope.  I must say that having observed this object through another 16 inch dob about a year ago, the view that Kevin showed me was the best I have ever seen of this elusive object. In fact, what is usually observed utilizing averted vision as a notch in nebulosity, was very clearly shaped like a horse head using direct vision. That is Kevin to the left with his very pretty scope.  In addition to the horsehead, we looked at M46 and the planetary nebula NGC 2438 superimposed on the cluster.  I very clearly saw two cluster member stars behind the nebula and a hint of a third.  Very cool indeed!

Back at the ranch, Jerry broke out the chips ahoy and we were ready for hunting down some more faint fuzzies.  I wrapped up the night with some interacting galaxies Jerry showed me, NGC 5353 and 5354, as well as viewing comets 81/P Wild, and 2007 Q3/Siding Spring.  Finally, I took a look at NGC 4605 in Ursa Major, a 10th magnitude oval shaped  galaxy.  This galaxy is fatter to the west and tapers somewhat to the east.

After a good nights sleep, Jerry and I set up our solar scopes to take a look at the Sun and share the views with the other party goers.  In terms of equipment, I was using my Lunt 60mm Hydrogen Alpha scope, to see feature such as active regions and prominences.  And for the first time, I was also using my TEC 140 apo refractor equipped with a Herschel Wedge (to the left) also made by Lunt Solar systems. The wedge enables white light viewing of the sun to reveal features such as sunspots and facula. Jerry had his new Lunt 152mm Hydrogen Alpha telescope...yes, you read that right, a 6 inch dedicated solar telescope!  There he is on the right with the scope.  The views through the Lunt 152 were simply jaw dropping.  The resolution and contrast of the hydrogen alpha image were simply beyond compare.  But enough about the equipment, this is after all an observing report!

I made two sketches of the Sun on Saturday, one using my 60mm Hydrogen alpha scope and the other using my TEC 140 with the Lunt wedge.  What is remarkable is the enormous prominence that is visible in the northwest in the hydrogen alpha sketch...in the short time I have been observing the sun I have never seen a prominence as large and bright.  Approximately 30 minutes after the sketch, the prominence had completely detached from the limb and was almost rotated 90 degrees!  Thirty minutes later the prominence had virtually disappeared. The white light sketch reveals  a large number of sunspots within active region 11054, as well as some facula on the solar limb.

Instrument: Lunt 60mm Ha/BF1200                                                       TEC 140 apo/Lunt Herschel Wedge

Eyepiece: Baader Hyperion Zoom at 12mm                                             Lunt Zoom at 7mm

Time of sketch 1550 UT March 13, 2010                                              1645 UT March 13, 2010
Solar Diameter: 32.18'
Carrington Rotation: 2094

After a day of awesome solar activity and observation, Jerry and I grilled some meat, washed it down with a couple beers and got ready for night number two.  I should mention at this point, that in addition to the astronomy, part of what makes this event so memorable is the camaraderie with other observers- and one of my favorite is George Robinson, known affectionately to us as The General Gorge.  The General references his rank in the US Army, and the Gorge references the misspelling of his name on the plaque he was awarded last year for finishing first in the marathon.  Not only did he finish first, but he conducts the entire marathon from memory.  He has not only memorized the order of the 110 objects, but he has memorized their positions in the sky.  The picture to the left is General Gorge patiently waiting for dark next to his dobsonian.  If you look carefully you can see the red ski goggles that he dons prior to dark to begin the dark adaptation of his eyes so that he may better find the faint objects that set shortly after the sun.  He is a great sport, an even better observer and we are fortunate to share his company each year.  He keeps Raquel Welch to himself, but we can live with that.

The seeing was not as good on the second night and again I busied myself with a couple more objects in Lynx as well as some other galaxies such as:
NGC 2424 ~ a very faint galaxy in Lynx at magnitude 13.1 that rewards patient observing with a brighter core and a spindle like shape.
NGC 2537 ~ known as the "bear paw" galaxy, resembles a planetary nebula more than a galaxy.  It is quite diffuse with a subtle unevenness to the glow.
NGC 3621 ~ a 9.2 magnitude galaxy in Hydra- mostly a faint smudge but this galaxy was sitting low to the horizon in the light dome from Tucson.  Clearly oval in shape and framed by some nice faint stars.
NGC 4125 and 4121 ~ 4125 is a small yet bright 9.9 magnitude galaxy in Draco, likely a tilted spiral.  It is accompanied to the south by the extremely small galaxy 4121 at magnitude 13.5.
NGC 5866 ~ A large and bright galaxy in Draco, at magnitude 10.2 it resides 38 million light years away and is mostly smooth in appearance.
NGC 4656 ~ known as the "hockey stick" galaxy in Canes Venatici.  This galaxy is magnitude 10.2 and interacting with NGC 4657 in the northeast which gives it the hockey stick shape.  the southwest extension of 4656 is much fainter.

NGC 4490 and 4485 ~ Also entry 269 in the Arp Atlas of peculiar galaxies, I decided to sketch this interacting pair.  Again, the sketch was black pencil on white paper and I inverted it after scanning to try and better represent the eyepiece view.  Each galaxy is actually a spiral galaxy that has been distorted by the other. In photos hints of spiral structure are still evident in the smaller galaxy. These galaxies have already passed their closest approach (perigalacticon) and are now speeding away from each other. A tail of stars stretches between the galaxies (not seen in the eyepiece!) which are separated by at least 24,000 light years

Next, I took aim at IC 3568 the "lemon slice" nebula in Cameleopardalis...Hubble photos reveal a yellow planetary nebula that looks like a slice of lemon...my scope revealed a smooth round disc of nebulosity with a 12th magnitude star to the west...please pass the iced tea. 

After another brief walk around, I decided to revisit comet 81/P Wild that I had observed on the first night and make a sketch.   Again, the sketch was inverted for your viewing pleasure.  It has a fairly bright, somewhat condensed nucleus and a diffuse coma.  Note the very faint tail extending to the west.  The tail is probably slightly exaggerated in terms of brightness, but I could not sketch it any fainter and represent what I saw.  Currently the comet is approximately magnitude 9.5 in the constellation Virgo.  It is approximately .714 AU from us, or 5.9 light minutes.  It is quite slow moving, covering approximately .4" of sky per minute...had I sketched the comet on the night before, it would have been located just to the lower left of the center of the star field in my sketch!

I went to bed quite satisfied with the event, and upon getting up Sunday morning Jerry and I decided we should do some more solar prior to packing up and heading home.  Again, I made both a hydrogen alpha and a white light sketch of the sun, using the same equipment as yesterday.

Time of sketch 1600 UT March 14, 2010                                           Time of sketch: 1520 UT, March 14, 2010

Carrington rotation 2094                       

Solar diameter 32.17

All in all this was a fantastic marathon, and if you have read this far, well, thanks!

Sundogs

On my way into work this morning I noticed some very pretty sundogs in the sky.  Fortunately I had my camera with me so I was able to pull over and snap a few shots.  This first picture gives you an idea of the overall scene.  (Make sure and click on the thumbnail so you can see the full size image).  The sundogs are the bright arcs on either side of the sun.  Note that in the image, the sun appears much larger than in real life.  This is due to the cameras sensor being saturated by the brightness (or, more accurately, me not knowing how to truly use the cameras features!)

Sundogs (technically called parhelia) are atmospheric phenomenon formed by plate-shaped hexagonal ice crystals in high and cold cirrus clouds. These crystals act as prisms, bending the light rays passing through them by 22°. If the crystals are randomly oriented, a complete ring around the sun is seen --- a halo. But often, as the crystals sink through the air they become vertically aligned, so sunlight is refracted horizontally -- as in this case, and sundogs are seen.  These two shots are zoomed in images of the sun dog that was on the right side of the sun.

This is a picture of some very bright sundogs taken in Fargo, North Dakota in the February of 2009...I am cold just looking at at!  If you would like to explore more about Sundogs and other similar atmospheric phenomenon, I would recommend you visit this webpage on atmospheric optics.

Solar Sketch 7 March, 2010

I had a nice opportunity to observe and sketch the sun today using My Lunt Solar Systems 60mm Hydrogen Alpha telescope (Pictured to the left).  Recently, I had Lunt upgrade the telescope to their new Pressure Tuning system.  This upgrade resulted in my ability much more precisely tune the etalon filter than with the previoius mechanical tuning wheel system.  This allows me to explore in more detail various features on the sun as I can very precisely tune the filter to varying parts of the Hydrogen Alpha band.

Today the sun was very interesting, as there are many filaments (the dark curving lines in the sketch) despite the lack of NOAA numbered active regions (AR).  AR 11051 is on the northwest limb of the sun, almost out of view.  In the northeast is an amazing "filaprom" that appears almost 3D in the telescope.  The filaprom is a combination of the filament - visible as a dark curving feature on the solar disc - and the prominence - visible as bright material off the limb of the sun.  As this is obviously the same feature, it is called a filaprom.  There is a another, smaller filaprom in the southwest.  Despite having no official AR number, there is a decent sized region of activity on the suns central meridian.  this region contains some very pretty mutipart filaments as well as a subtle brighteneing which may indicate an increase in activity coming to this region.  To the right is a photo of the sun, in hydrogen alpha, from the Solar Monitor website approximately 4 hours prior to my sketch, which is below.

Instrument: Lunt 60mm Ha/BF1200
Eyepiece: Baader Hyperion Zoom at 12mm

Time of sketch 1545-1610 UT March 7, 2010

Solar Diameter: 32.23'
Carrington Rotation: 2094

The other Leo Triplet

Tonight was a spectacular night at the Lost Pleaid Observatory.  A very mild day with little change predicted in the weather over the next few days (due to a high pressure system) resulted in skies that were steadier than they have been in some time.  On a scale of 1-5 with 5 being perfectly stable, tonight was a 4 at the worst moments and at times the seeing ranged to an almost perfect 5/5.  With several hours of dark skies before moonrise, I decided that I would push the limits of my 5.5 inch refractor a bit and observe some galaxies.

Before the serioius hunting started, Ian joined me in the observatory which is a rare pleasure for me.  I showed him the great orion nebula (M42) and the trapezium stars, and he remarked that the A through D stars were in the shape of a butterfly- I have looked at this group of stars countless times yet I have never noticed this.  Maybe we should observe with kids more often!  I also showed him M82 (the Cigar galaxy) as well as the very pretty open cluster M46 which has a planetary nebula (NGC 2438) superimposed on the cluster.

The constellation Leo (The Lion) is home to many galaxies.  So many in fact, that under dark skies one can literally get lost observing them!  Observing galaxies in this constellation requires a good star chart and the one that I prefer to use in the observatory is Sky and Telescope's Pocket Sky Atlas.  It is spiral bound, easy to read under a red light, and contains just enough objects to keep one busy for years.  It is also cheap, which is a rarity in this hobby.  Copies can be found for approximately $15.  I like this atlas so much I have actually purchased additional copies to give to other amateurs as gifts.  Certainly one needs a star atlas that goes deeper, however this atlas is suffiecient for 95% of my observing.

Leo is home to a famous grouping of galaxies called the Leo Triplet.  The triplet consists of M65, M66 and NGC 3628 and can be seen in the photo to the left.  I was observing these galaxies tonight and decided to take a look in the atlas and see what other targets may be nearby.  I turned to the page where I would find Leo and started to look near Regulus (the brightest star in Leo) and the famous sickle pattern of bright stars.  I immediately noticed NGC 3190 and NGC 3193 sitting just east of Algieba, the third brightest star in Leo.  As these galaxies are approximately 11th magnitude I knew that they would be a challenge in my refractor, but as they were not large, they should be visible.  I pointed the scope at the coordinates and was rewarded with a view of these interacting galaxies.  After observing them for a few minutes I decided to make a sketch.

Instrument: TEC 140 APO        Eyepiece: 8mm (122x)
Time of sketch 0350 UT, March 4, 2010

                   NGC 3190             NGC 3193
RA:             10h 18.1m              10h 18.4m
Dec:            +21 deg 50 min      +21 deg 50 min
Mag:           11.2                       10.9
Size:            3.5' x 1.4'               2.2'
Distance:     53 million LY          56 million LY

After making the sketch, I decided to take a look on the internet to see what was out there on these galaxies.  To the right is a photograph of the galaxies from the Sloan digital Sky Survey.  Not that interesting, I'll admit.  However, I did turn up the image below (credit: Adam Block/NOAO/AURA/NSF ) which is absoultely stunning.  Not only are NGC 3190 and 3193 featured, but a third galaxy, NGC 3187 is in the field.  Hence, the title of this post, the "other Leo Triplet."  I would highly recommend you visit the source of this photo where you can view a high resolution version of this image.  And if you own a large scope, you can observe all three of these galaxies!