Sunday, November 24, 2013

Lifting Prominence

If you have been following the weather here in Tucson, or perhaps watched the roasted Duck that the Arizona Wildcats football team served up yesterday afternoon (Bear Down!), you know that we have had record November rainfall here in the naked pueblo.  As the low pressure system loses its local organization and begins to move out we are left with partly cloudy and fairly unstable skies.  Still, I set up my 60mm HA solar telescope to take a look at the Sun between clouds this afternoon and was delighted to see some nice limb activity.  As active region 11899 departs, it is putting on a farewell show- and the prominence activity on the limb is the result.  After a few minutes observing and allowing the telescope to reach thermal equilibrium, I attached the ASI camera and took a 30 second avi of the Sun.  Given the lack of stability, I only used 300 frames (out of about 1000) and stacked them to get the image below.  It is at the full resolution of the camera and slightly reduced in size for aesthetics.  In addition, I took the liberty again of brightening up the prominences in order to show the one that is lifting off.  It is slightly over-sharpened, I think, but given the low quality of the original data, no complaints.

And just for fun, here is the same image inverted:

Here is a similar image, binned 2X2, with less attention to the prominences:

Sunday, November 17, 2013

Solar improvements

This weekend is the 2nd annual Arizona Science and Astronomy Expo at the TCC.  This event which features speakers and vendors from around the world is essentially a playground for amateur astronomers. The Mount Lemmon SkyCenter has a booth and after spending the morning publicizing our activities I spent the afternoon networking with vendors and visiting with old friends.  At left is my colleague Dr. Maria Perreira and I in our booth preparing for the expo opening.

While a boy can dream (see the beautiful TEC 180 on an Italian Mount at right), one of the accessories that I have had my eye on for some time was a side-by-side dovetail system which would allow me to use two telescopes at once.  This is very useful in solar outreach as I can set up both my hydrogen alpha and white light telescopes at the same time.  In addition, it would allow me to mount both my 12 inch SCT and small 90mm refractor at the same time for night use.  I spoke with Anthony Davoli from ADM Accessories, who had been set up next to us last year and after some deliberation took the plunge on a very nice system.  Not only does it allow for side-by-side mounting, but one of the saddles is adjustable in altitude and azimuth allowing for precise alignment between instruments.  I spent some time figuring out how to balance this set up and was able to successfully utilize both solar telescopes this morning.

Of course, I also spent some time taking some pictures of the Sun through both telescopes.  Seeing conditions were about average and the Sun is putting on quite a show right now.  One of the next items I would like to find is a reducer of some sort that would allow me to fit the entire solar disc on the chip of the ASI120MC camera.

First up, the white the images to enlarge them to full size.

The image below was taken at the camera's full resolution (the one above was binned 2x2) and you can see that it suffered a bit from the atmosphere.  However, it does show the very large spot quite well, including some detail within the umbra.

Next, the Hydrogen Alpha...The image is binned 2x2 and I played around with brightness and contrast of the prominences to try and bring them out a little.  These are features that are much fainter than the Solar disc and I am impressed that the camera is capturing them at all with the settings I am using to capture the hydrogen alpha detail in the chromosphere.  Again, click the image for full size.

Monday, November 11, 2013

Veterans Day Solar Images

The image below was captured at 8:54 AM local time (1554 UT) this morning.  Seeing conditions were slightly below average with the limb of the Sun in constant motion.  At about 30 frames per second I am able to negate the seeing conditions somewhat, however, compared to the images I captured on November 8th when the seeing was quite good, I am able to appreciate the difference on a day like today.  This is a stack of 250 frames out off 1000, binned 2x2, processed in Registax.  Using Photoshop I also increased the exposure setting for the prominences on the upper limb of the resulted in a cool look although the process did introduce some brightening artifacts on the limb.

The image below was taken at the full resolution of the little ZWO camera, 1280x960.  Whenever I try this it seems that the resulting image has a grid pattern that is difficult to remove in processing.  In addition, stacking a good number of frames results in artifacts that make the image appear as if it were a completed jigsaw puzzle.  Focus was a little off, and it was taken a few minutes earlier than the above image, so perhaps the atmosphere steadied a bit for the later capture.  In any event, here you have it-

Sunday, November 10, 2013

November 10th Sun

Clouds are coming fast this morning at the Lost Pleiad Observatory.  Fortunately one of the benefits of having things set up semi-permanently is that mount, telescope, and camera are ready to go at a moments notice...just like I used to be.  After last nights marathon observing session which lasted until nearly 3 AM I had a bit late of a start for solar observing, however, seeing conditions still seemed slightly above average.  Generally, I find that the best atmospheric conditions for observing the Sun are between 90 and 120 minutes after Sunrise.  Some days the window lasts a bit longer, but it rarely starts earlier due to the low Sun angle.

The two images below were taken through my 90mm Stellarvue f/6.3 triplet with  Lunt Solar Systems Herschel Prism and a polarizing filter.  Naturally, the camera is the same one I have been playing with, the ASI120MC.  The images were taken without regard for the directional orientation of the Sun.  If you imagine the Sun as a clock face, South is actually at about 10 O'clock; however, I like the composition better with the spots at an angle and the large group at the upper right.  The midpoint of the exposure was at 11:05 AM MST (1805 UT).

The large spot group at upper right is NOAA Active Region (AR) 11890 which has been spewing out very strong X-class flares over the past few days.  Often individuals want to know the size of spots relative to the Earth- and in fact we could line up about 110 Earths across the approximately 1 million mile solar diameter.  So clearly the large spot within 11890 is much larger than the Earth.  In fact, AR 11893 which is the home of the second largest current spot group at lower left also contains a spot that is much larger than the Earth.  These spots (while still quite hot) are relatively cooler regions in the solar atmosphere which is why they appear darker.  They are areas of intense magnetic activity, however, and the sheer size of 11890 is an indication to keep an eye out for flaring activity.  The image below was taken with a 2x barlow lens immediately after the above image, at 11:13 MST (1813 UT).  Both of these images are stacks of approximately 500 of 1500 individual frames processed in the freeware program Registax and adjusted a little in Photoshop.  I am pretty unhappy with the processing, but that is what staying up late will do to me the next morning....

Jupiter's bland side

I am a glutton for punishment.  Not only did I watch/listen to the entire UA vs. UCLA football game last night, I stayed up until nearly 3 AM to take an image of Jupiter and also to observe Comet Lovejoy (C/2013 R1).  The comet is fantastic right now sporting a very large coma and a condensed nucleus.  It is a much better target than ISON, despite the apparent lack of a tail.  The comet is high enough over the eastern horizon by about 1 AM to start observing, although as it rises higher there is less atmospheric extinction and it appears brighter.

Jupiter on the other hand was much less forgiving than the comet last night.  Comets are inherently fuzzy objects and one does not notice the turbulent seeing conditions as readily.  Point the telescope at Jupiter and all of a sudden it looks like a living and breathing monster of a planet.  The image below is a stack of only 200 frames (out of 1800!) aligned, stacked and processed in Registax.  Left to right, the moons are Europa and Io.  According to Firecapture (freeware used for image acquisition), the ephemerides are:

CMI=82.5° CMII=316.8° CMIII=107.5°  (during mid of capture)

The image was taken through my TEC 140 with a 2x Barlow and the ZWO ASI120MC camera.

Friday, November 8, 2013

Solar images in Hydrogen Alpha and White Light

Not a lot of time to spin words today as I am about to head off to work...but I had a bit of time this morning to capture the Sun not only in Hydrogen Alpha, but also in white light.  I am pretty happy with the images and am feeling like I make a little bit of progress each time I use the camera.  First off, some of the HA images...this first one I shot to try and show off the "filaprom" at the had a 3D look visually.

This next image may be my best effort yet...processing skills limited me far more than the data.  Incidentally, the active region near the center of the Sun has been spitting X class flares, including one around 9 PM last night.

For white light, I captured the image through my Stellarvue 90mm triplet apo and a Lunt Herschel Prism, using a polarizing filter.  This is my first successful white light image:

Having fun now!

Wednesday, November 6, 2013

First time Jupiter!

I awoke at 4:30 this morning specifically to observe Comet ISON, currently cruising through the constellation Virgo as it nosedives toward the Sun.  As comets go it was not that remarkable but I wanted to see it prior to it's close encounter with El Sol on November 26th.  Once I finished obseving I was not going to go back to sleep so I tried my hand at imaging Jupiter with the ASI120MC video camera that has been the subject of the past few posts.

The image below is a stack of approximately 900 frames out of 1510 processed in Registax.  The image was captured through my TEC 140 with a 2x Barlow in slightly below average seeing conditions, using the freeware program Firecapture.  Looking at the log file that is automatically generated in Firecapture, I noticed that it provided ephemerides and other information for Jupiter.  While I am not sure the source of these, pertinent data is as follows:

CMI=320.2° CMII=223.8° CMIII=13.5°  (during mid of capture, which was 12:48:36 UT, Nov. 6th)

For a first attempt, I was nearly jumping up and down...of course I needed to stay warm and this helped restore blood flow....but seriously, with more practice (and perhaps a 2.5X Powermate in my future) I believe the images will only get better.  The moon closest to Jupiter is Callisto, and the two moons further out are Europa (upper) and Io (lower).

Monday, November 4, 2013

November 4th Sun

Quick capture this morning, trying to be more careful with the etalon tuning and also using a slightly shorter exposure time to freeze out some of the turbulence.  Seeing was not quite as good as yesterday but I still ended up with a reasonable image.  I think it is about time to start asking solar imagers about the settings that they use in Registax for the wavelet functions...I am having difficulty finding a good balance of sharpening/denoising.

Best thing about this above image is that it can be directly compared to yesterdays image and one can appreciate the changes and rotation of the Sun over 24 hours.  Note that I was able to capture some prominence detail along the limb in the right side.  To truly bring out the prominences, which are faint, the settings need to be adjusted (e.g. longer exposure, higher gain rate) and the surface detail will wash out.  The adventure continues...

Sunday, November 3, 2013

Solar imaging take two

A week has passed since I first tried out my new ASI120MC camera, and I was able to image two targets with the camera over the past 24 hours:  Venus yesterday evening, and the Sun this morning.  Seeing conditions were variable last night as I attempted to capture Venus.  I have a very small window from my observatory where I can actually observe Venus around sunset before it quickly passes behind a tree in my neighbors yard.  Venus is inherently a difficult target to image in the evening skies as it is generally not more than 20 degrees above the horizon, and last night there were also clouds rushing in from the west.   As I live east of Tucson I am also looking right over the city when I observe to the seeing conditions for evening apparitions of Venus are always a mixed bag.  I did manage to create the image below and it was my first attempt at using a cheap 2x Barlow lens with the camera.  In order to reach focus I also had to use a mirror star diagonal, which is likely not ideal for imaging.  Below is the result of stacking about 150 usable frames (out of 2000) and some processing in Registax.

While I was hoping to do some visual observing last night and ultimately try to image Jupiter, the aforementioned could bands rolled in and we were treated to a long steady rain lasting until near midnight.  This morning skies were mostly clear with some passing thin cirrus and as the coffee was brewing I set up my 60mm Lunt HA scope to try and create another solar image.  Seeing was fairly steady and other than the passing bands of cirrus I was able to take an avi of approximately 2000 frames.  The result is below, following a stack of about 750 frames and some processing in Registax.

In some ways, this image is better than my previous attempt.  Clearly (pun intended) the improved seeing conditions helped me to start with better data and more usable frames.  Having steady skies also made focusing a bit easier.  I also happier with the sharpening and denoising I did using the wavelet functions in Registax, although I could still be more effective with these techniques.  The exposure settings were not ideal as some of the active regions are a bit washed out and I also did not have the etalon filter on the telescope tuned as precisely as I would have liked.  While I had it tuned for the eyepiece I was using prior to image capture, it seems that it needs to be tuned slightly differently for the camera. This tuning process as well as precise focusing is something that I need to continue to explore if I am to improve the images.  If I had to rank the importance of these factors, focusing is probably number one, followed closely by the tuning, with the atmosphere being the third consideration (and the one I have no control over).  As I become more fluent in the exposure time, gamma, and gain rate settings, I will be able to compensate slightly for the atmospheric stability being less than perfect.