Saturday, August 12, 2017

April Observing Report


April 6, 2017
A cold front came through yesterday. Last night was clear and dry but tonight is even better EXCEPT for the nearly full moon looming overhead. Came out at 2000. Set up the ASI071MC-COOL at prime focus with the Lumicon DS filter. I was able to slowly drop the camera's temp to -20.

Synched the model on Dubhe and went to M-109 and started taking 60 second exposures at gain = 400. Frustratingly the camera / computer is still dropping 30 – 50% of the frames! A 60 sec exposure put the light curve maxima at only 15%, so I upped the exposure to 120 sec. Dropped about 7 frames in a row, very frustrating! I gotta change the wiring setup. I'm wasting too much time waiting on frames. Finally got an image and the 2 min exposure moved the luminescence to nearly 30%.

I was using a long active extension USB cable through a USB 3.0 powered hub to connect the camera to the computer. I removed the powered hub and the USB 3.0 extension cable. I hooked the StarShoot guider cam into the ASI071MC-COOL hub and ran a USB 3.0 cable from the ASI071MC-COOL to the laptop. Downloads are much faster and much fewer dropped frames at first with 30 second frames. When I upped the integration to 2 min, still there are too many drops ( nearly 50% of 2 min frames were dropped). Very frustrating. When I finally started imaging the M-109 the image contains an ice crystal, a lot of fogging, and a textile pattern!


I turned the cooling off and after a few minutes the ice, fogging, and textile pattern disappeared. I turned the camera's cooling to -10 C. As M-109 was approaching the meridian so I changed targets to M-101. At 2315 the ambient air temp is 54 F (12.2 C) with 63% humidity and the skymeter reading is 15.0 at the zenith due to the > half moon that is just past zenith. Pointing the skymeter towards Ursa Major the reading is a much more respectable 18.0.

Messier 101, NGC 5457, in Ursa Major is 21 million light years from earth. The face-on spiral galaxy is estimated to contain 1 trillion stars! Started imaging M-101 and got 5 x 120 second frames in and stacked in AstroToaster, looking pretty good. Then the camera / computer dropped the next 10 frames - ARGH !!


The image adjustments in AstroToaster are pretty good but I have to learn the interactions of the controls. Also I need more frames to bring out the detail in the arms. The object is getting too far to the west and into the higher light pollution region of my skies. So further frames will have to wait for another observing session. Shutting down at 0050.

April 8, 2017
Came out at 2100 to a beautiful night. Clear with no star twinkle, but a full moon sitting high in the sky. The temp is 63.3 F with 71% humidity and a dew point of 54 F. A slight occasional breeze. I set up the camera the same as last night: at prime focus, Lumicon DS filter, and gain = 400. I'll stick to -10 C on the camera cooler to hopefully avoid the textile pattern I saw at – 20 C. I still have the camera on a USB 3.0 cable direct to the laptop and the autoguider in the hub of the ASI071MC-COOL.
Cooled the camera down to 0 and held for 10 + minutes. Found the mount was parked slightly East in RA, so I had to reset counterweight down and now I'll have to rebuild the model; Arturus, Spica, Mizar, Denebola, Vindemiatrix, Castor, Capella, and Alphard.

I started out pretty good with the fast 8 sec frames while building the model, but when I went to 60 s frames the time to download got longer and I started dropping frames. I changed from RAW16 to RAW8 but it froze the SharpCap program. After several minutes of the program not responding, I killed it and restarted. Resuming my Herschel 400 project.


H 34-1, NGC 5248
Found that an exposure of 90 sec gave a maximum on the histogram at 40%. A little high but I'll go with it. I got 6 frames stacked, but dropped 4 so far. Seems like it gets into a mode of dropping frames, now I'm at 6 good frames & 8 dropped, so I've dropped the last 4 frames in a row. Finally got 19 good frames on this object.


This object is a face on spiral galaxy with a prominent arm on the N trailing back to the W and another arm on the S trailing back to the E. Apparent size is ~ 3 x 1.5 ', I'm missing the outer arms in my images. There are hints of inner tighter arms around the center. The center is not overly bright and elliptical running NW to SE. The galaxy is in a nice star field of 19 similar magnitude and size stars and many other fainter ones.


H 9-6, NGC 5466, Melotte 124
Went to NGC5466, a GC in Bootes. Set the exposure to 90 sec which gave a histogram curve maxima of around 27%. The images are very washed out due to the full moon.  The camera is still running at a gain of 400 and the chip temperature is -10 C.

This is a loose GC about 10 ' in diameter. The GC is roughly circular with a linear string of 5 stars on the NE corner. The star field is relatively sparse with no large or bright stars in the FOV. The GC is not saturated in the core. Many individual stars are seen.
I've cropped off the bottom 10% of the image due to amp glow.  Use of dark frames will eliminate that but for now this camera provides such nice fields, a little can be sacrificed without harming the image.

At 0004 it is 54 F and 88% humidity. The skymeter reading was 17.08 with the full moon near the meridian.

H 99-1, NGC 5557
This is a small (2.4 x 1.9 arcmin) galaxy in the constellation Bootes.  It is 132,700,000 light years from earth.  At 2 min exp yielded a light curve peak @ 31%. The galaxy is quite small at 2.4 x 1.9 ' but zoomed in my image is similar to that from the Deep Sky Survey (DSS). I captured 11 frames and then I stopped.

This is a small face on galaxy with a bright core that is slightly elliptical, while the visible halo is nearly circular. The diameter of the halo is roughly 3 core diameters. There is a bright star in the halo at the ESE position. The star field contains several bright stars that are nearly as big and bright as the galaxy's core. 


H 189-1, NGC 5676
NGC5676 will be the last target for the night. A 2 min exposure put the apex of the light curve at ~ 28%. I note that the bottom of each image contains a bright streak across the frame. Not sure if this is amp glow or what. I got 7 frames and it dropped 3 – ARGH !

A spiral galaxy inclined about 45 degrees and tilted towards the earth at a shallower angle. It is rather small. The core is barely more luminous than the halo. No discernible features from the halo. The galaxy is in a nicely populated star field with 50 or more stars. Two stars are rather large, at least larger than than the galaxy center.


I noted that the guiding graphs look terrible but the images are reasonable. I need to work on the polar alignment , balance and other causes of bad tracking. I shutdown for the night at 0204. Note the camera ran all night at -10 with no perceptible freezing of the sensor.  

April 14,2017

I returned the ASI071MC-COOL under warranty for replacement. There have been at least 2 other reports of similar issues on the ZWO forum.   ZWO is recommending people clean the sensor with alcohol, but I declined in favor of a replacement. Hoping the replacement will be here in time for the Deep South Spring Scrimmage. In the interim, if it ever clears up, I'll use my Mallincam.

April 20, 2017
Received my replacement camera today.  Came out a little after 8 on a clear, warm night. Setup the ASI071MC-COOL at prime focus with the Lumicon DS filter. Have the camera on a USB 3.0 cable direct to the laptop and the autoguider in the hub of the ASI071MC-COOL. Setup SharpCap for RAW16 color space with FITs files, no binning. Cooled the camera to 10 C and turned on the dew heater. After 20 min turned the cooler down to 0 C and then down to -10 and finally -20.  The camera got to -19 C but that's as cold as it could go.

H 186-1, NGC 5195, Messier 51b
Got a nice image of the whirlpool galaxy (NGC 5194, Messier 51a) and its companion, the smaller NGC 5195.   This galaxy is 25 million light years from earth in the constellation Canes Venatici.   Used  AstroToaster to live stack and adjust the images.  AstroToaster appears to be a better stacking program than SharpCap and it has, IMHO, better image adjustment tools.  The image is 11 x 120 seconds at gain = 400 with no dark frame subtraction.  

I did adjust the levels to brighten the image and improve contrast in GIMP 2.8.22.  

Messier 13, NGC 6205
Went to M13 and caught some nice images of The Great Globular Cluster in the constellation Hercules.  The image is 12 x 90 sec exposures at gain 350 and no dark subtraction.   The camera was running at -15 C.


Messier 57, NGC 6720
A little after 0200 I went to M57 (the ring nebula) and started to capture images and the image looked foggy with a center circle that was darker. I suspect this was from extended operation of the cooler at near 100%. I turned off the cooler until the chip reached near ambient (15 C) and then turned the cooler on again to 0C. After a few minutes I lowered it to -10 C. After a few images the dark circle reappeared at -10 C.  Captured images of the ring with AGC 400 & 3 min exposures. I noticed star trailing and the PhD graphs showed some big spikes in RA, both + & - . Image shift is severe at this point. Not sure what's happening. The mount is not giving any errors.

Interesting the image is black & white as it had color in SharpCap.  Shut down at 0303, will look at this tomorrow.
April 24, 2017

Came out a little after 2000 on a cool (for late April) and relatively dry night. Setup the ASI071MC-COOL at prime focus with the Lumicon DS filter. Have the camera on a USB 3.0 cable direct to the laptop and the autoguider in the hub of the ASI071MC-COOL. Setup SharCap for RAW16 colour space with FITs files, no binning. Gain set at 300 tonight to start. I want to experiment with different gains to determine the impact on the light curve & noise. Cooled the camera to 10 C and turned on the dew heater. After 20 min turned the cooler down to 0 C.


At the end of last session I experienced some significant drift that overwhelmed the guider. I wonder if the mount slipped on the azmituh or altitude locks. Will check that first. Went to Alphard in Hydra. Started drift and after 10 min there is drift up but nothing left or right. I'll take that as a good sign and move to a star in the East. Went to Zubeneschamali (Zubenesch) in Libra just above the E horizon. After 5 min there is drift downward ~ ½ star diameter, but not left or right. From what I've read about drift alignment, up & down drift is not a concern. Seems it should be but I'll have to read more on this later. For now I'll get started observing.
I checked the focus with SharpCap's Bahtinov mask tool. It is quite nice and helpful. Focus achieved at 34.5 mm.

On NGC 5689 a 2 min exposure at 300 gain yielded a light max of ~ 2%. A 3 min exposure yielded an ~ 7 % max.  Took a few more to populate the below table.

gain
exposure time
light curve max (%)
300
120
2
300
180
7
350
180
14
350
120
8
400
120
15,15
400
180
22

Other than the first table entry we see that increasing gain by 50 will increase the  light curve maximum by approximately 50%.  Increasing the exposure from 2 to 3 min (a 50% increase) increases the light curve maximum by a variable amount (250%,  75%, & 46%).  I should have captured the amplitude of the light curve at maxima, but failed to do that on all the tests.  Something to try another time, but this provides some insight into the system's response to varying exposure and gain.

At 2225 it is 58 F with 96% humidity and no wind. Sky meter reading is 18.99.

H 188-1, NGC 5689

A small faint (mag 11.9) galaxy in the constellation Bootes that is angled away from the earth.  It is approximately 116 million light years from earth.  The core is large and bright but no details are visible in the halo.  The star field is pretty well populated and there are 3 other galaxies in the FOV; NGC 5682 (mag 13.9), NGC 5683 (mag 14.8), and NGC 5693 (mag 13.6).  The image is 9 x 180 seconds at a gain of 400 gain.  The amp glow along the bottom of the frame is evidence that no dark subtraction was employed.


 H 195-1, NGC 4111 
The camera cooling is holding steady at -10 C with no visible artifacts in the images and at 19% power.  The object is a near edge on galaxy with a bright core in the constellation Canes Venatici.  The halo is approx 3 core diameters in radius and is oriented NW to SE.  No detail is visible in the halo.  There is a bright, large star to the SW of the galaxy.  There are 3 other galaxies in the FOV. Two are SW of NGC 4111; NGC  4117 (mag 13.4)  and 4118 (mag 16.0).   NGC 4109 (mag 13.3) is  NE of NGC 4111.  The image is 6 x 180 seconds at gain 400.  


H 701-2, NGC 6207
A small faint galaxy with a smallish core that is rather dim.   There is no detail evident in the halo.  The halo radius on the thin side is about 1 core diameter.  In the long direction it is 3-4 core diameters.  The galaxy is in a well populated star field.  There is a large star just off the FOV to the E.  The DSS image shows more of a molted appearance, but I don't see that in my image, which is 6 x 180 seconds at gain = 400.

At 0046 the temp is 57 F with 96% humidity and a sky meter reading of 18.99

H 759-2, NGC 5907
This will be the last target of the night. Still gain 400. PhD started giving me warnings about max RA duration is preventing PhD from making corrections. Not sure what caused this, likely the part of the sky I'm pointed at. Images have significant star trails. To complicate troubleshooting, the camera / SharpCap is posting partial images. The trailing stopped after a couple of minutes without any intervention by me. Not sure what to make of it. The stars are now nicely shaped starting in image # 4.   I noticed in image 3 of NGC 5907, the image has a dark circle like dew on the sensor. Raised the temp to 0 and then to 5 C.  This dew issue continues to plague me.

A large edge on galaxy in the constellation Draco.  The galaxy is oriented NW to SE.  The core is barely brighter than the surrounding halo.  The star field is nicely populated with many similar size & brightness stars.  The image is 7 x 180 seconds at gain = 400.

Shut down at 0145.


April 25, 2017
Around 10 am I installed the auxillary desicant tabs in the ASI071MC-COOL. Hopefully this will avoid the dark circle in the images like I experienced late last night.

Came out a little after 9 pm on another coolish (66 F, 90% humidity) clear night with a light breeze. Created a new PhD dark library for 3 – 6 seconds with 10 exposures each. Hopefully this will help reduce the noise and improve the S/N on the guide stars. And it did, I went from a S/N of 12 to 46 with the new darks.

Took a new series of darks on the ASI071MC-COOL at 180 sec & gain 400 @ -10 C as RAW16 FITS. Hopefully it will eliminate the glow along the bottom of the frame.

H 42-4, NGC 4631, Caldwel 32, "the Whale & Pup (NGC 4627)
The guiding is poor – swinging from -2 to +2” on both axis with occasional larger swings in RA. I saw this last night when the scope was pointing near the zenith. I'm not getting any Gemini errors but perhaps I'm not sufficiently balanced. The tracking settled down and I took 10 images of 180 sec each and stacked at gain= 400.  The dark subtraction did help to remove/reduce amp glow.

An edge on galaxy in the constellation Canes Venatici that is thicker on the S end than the N.  There is no discernable central core but there is a brighter region just to the S and W of the center of the visible galaxy.  The galaxy is oriented NNE to SSW.  Also visible in the FOV is a companion galaxy (NGC 4627, "the pup").  It is a small roughly circular galaxy located just W of the center of NGC 4631.  These galaxies are located in a nice star field with a loose grouping of over a dozen bright stars to the WE of NGC 4631.  
Cooler is holding -10 C well at 22% power. No artifacts noted on the images thus far.   At 2340 it is 61 F with 94% humidity and a sky meter reading of 18.92.

H 40-6, NGC 6171, Messier 107
I wasn't able to get any of the targets around the N pole, so I moved back to the E to NGC 6171 in the constellation Ophiuchus.  I found it easily and cooled the camera back down to -10 and I got the circle back !!!.  Had more difficulty guiding with wild RA swings. I had recalibrated PhD before this. Not sure what is causing this, but it is screwing up lots of images!

After a few minutes the tracking settled down somewhat (I didn't do anything) and I was able to capture eight images of NGC 6171 with nice round stars. The computer dropped a few frames which prolonged the process and raised the aggravation level.

Note on this GC (NGC 6171) a 3 min exposure with gain = 400 yielded a light curve with the max at just under 20%. So even with reasonably bright (mag 7.8) objects it takes ~ 3 min exposure to capture. Dimmer objects like nebula will likely require me to take longer exposures.

This is a nice GC in a rich star field.   The core of the cluster has many discrete stars visible in a roughly circular grouping.  On the N side of the GC  there is a line of stars running NE to W.  There are 5 larger brighter stars in this FOV.

Shutdown at 0156.

April 30, 2017

Came out at 2330 on a windy night after a stormy day. Clouds are clearing but still prevalent. Checked scope balance and found it fine in RA & Dec. I did find the W azimuth lock blot a bit lose and tightened it. Not sure if that accounts for the poor tracking when the scope is near zenith.   I'm using the ASI071MC-COOL at prime focus with the Lumicon Deep Sky filter + a Badder UV/IR cut filter. This is my first time using the UV/IR filter on this camera.

I captured a few images of the Ring nebula (M 57).   Images are 180 sec, gain 400, -10 C, dark frame subtracted in SharpCap. Intermittent clouds are disrupting some images & affecting the guiding. I'm noting a small dark circle near the bottom of the image that I haven't seen before and also an arc to its NW. I suspect these may be from the UV/IR filter.  Focus looks a bit off.   Certainly not my best image of this iconic object.

Sky meter reading @ 0232 = 19.10, 59 F, 83% humidity, with only light breeze now. Most of the clouds have cleared except for some low in the east.

I dropped 3 images out of 10 taken on M57, very frustrating! I hate to spend the money on a laptop, but that may be the only solution. Also the histogram colors were not well centered with red to the left of the white and green & blue to the right.

It is after 0230 and the mosquitoes are irritating me, so I'm shutting down.

Monday, July 17, 2017

March Observing Report

March 15, 2017
I setup with the same optical train as last time; the VRC 10", with the Mallincam 2” 0.75x Focal Reducer and the ASI071MC-Cool. The 2” Lumicon Deep Sky filter is on the front of the FR. I set the camera cooler to -10C and turned on the dew heater. The camera gain is set at 400 to minimize exposure times.  I opened the roof to a cool, clear night.


I started off the night with Jupiter.  I've never had much success with planetary images.  I blame it on the high humidity and the resultant poor seeing in SE Louisiana, but I'm sure my technique is also to blame.  From what I've read I might do better stacking planetary frames in Registax.


Started the autoguider and began an image of the Orion Nebula. Wow, at 30 & 60 second images were wonderful, albeit noisy until several are stacked. Sharpcap hung while changing the exposure duration.  The autoguider keeps the image rock steady. This is the first time I've captured the arching structure of M43 in my images.  The below image is 6 x 60 seconds at gain of 400.  The Trapezium region is blown out.  A larger number of shorter exposures would likely yield a nicer image.


Messier 42, the Great Orion Nebula, is approximately 1,344 light years from earth.  The region includes clouds of neutral and ionized gas, dust, star clusters, and reflection nebula.  The much smaller Messier 43 is 1,600 light years from earth and is separated from Messier 42 by a dark dust lane.

I noted that when stacking in SharpCap, that many frames appear to be dropped. I went in the house to get coffee and was gone 10 min while stacking 1 min images. When I returned it showed only 2 stacked!  I think this is because in the stacking routine I asked it to align the frames. I'm not sure why SharpCap was rejecting so many frames.  That coupled with frames that failed to even load greatly slows down data collection.  I turned the align feature off and it is then stacked fine but some frames were still dropped.

At 2240 the temp is 42 and humidity is 80%. Sky meter reading is 18.60. Sky looks very clear but not my best sky meter reading.  Shut down at 2346.
==
March 18, 2017

Came out at 2100 on a nice night with scattered clouds, 67 F, 96% humidity and no wind.  I set up the ASI071 at prime focus with 4” of focuser rings and no extensions or focal reducers. I do have the 2” Lumicon DS filter on the end of the camera's nose piece.  I achieved focus at 35 mm on the focuser with this setup.  Note for this setup I had to significantly adjust the scope on the mount's dove plate to achieve balance

H 205-1, NGC 2841
Is a galaxy in the constellation Ursa Major (the big dipper) and it approximately 46 million light years from earth.  The galaxy is tilted away from us by 20-30 degrees.  The galaxy is surrounded by a nice star field.  Four minute single images didn't tease much structure out of the galaxy.  I need to stack but my camera is close to hitting the mount so I can't go any longer on it.


I noticed that with the ASI071MC-COOL camera in the focuser with the writing upright, the mount directional arrows work in reverse from the Mallincam.  I uploaded a single 240 second image (gain = 400) of NGC 2841 to astrometry.net to measure the field size.  It reported 40.5 x 26.9' with a pixel scale of 0.491 arcsec / pixel. This measurement allows a calculation of the reduction provided by the 2" 0.75x Mallincam Focal Reducer was 0.771.   This compares very favorably to the 0.770 observed reduction previously measured with my Mallincam Extreme.

 The astrometry.net report also showed that "up" is at – 88 degrees so the camera's orientation is a bit off.  I suspected based on the mount directional keys that it would be closer to 180 degrees.  In the future I'll mount the camera in the focuser with the writing on the camera's back upside down to reverse the slew direction to what I am accustomed to.


At 0043 it is 63 F and 98% humidity. Starting to get dew on some surfaces.


H 43-1, NGC 4594, Messier 104, The Sombrero Galaxy
A very nice galaxy nearly edge on, turned towards us by just a few degrees.  It has a bright core and the full top half of the galaxy is illuminated.  The galaxy is oriented N-S and a prominent dust lane is evident.  It appears to be approximately 8 ' long.  The galaxy is in a rather sparse star field.

  The above image is a stack of 10 x 120 seconds at gain = 400.  Stacking done in SharpCap.  There is a little illumination (amp glow?) on the bottom of the image, especially on the left.  I'm running the camera at -10 C.  A longer exposure would have been better to pick up more details.

H 78-1, NGC 2985
This is a nice spiral galaxy in Ursa Major located 64 - 67 million light years from earth.  I took a stack of 5 x 240 seconds at gain = 400 and with the camera operating at -10C.  

I've been seeing issues with ice formation on the chip at temps more than the -10 C setting. However tonight I'm getting a big circle of dark hazy nature so I have to turn the cooler off to make it go away. This isn't a good thing as it hurts the image and increases the noise level. Perhaps I need to add the auxiliary desiccant tablets to the camera.

Since I couldn't discern any detail of the galaxy, I didn't count this observation towards my Herschel 400 project.  Similarly I tried H 168-1, NGC 3184 but had similar issues with distortion of the image.   At 0148 clouds rolled in and ended the session. Learned some more about the camera & SharpCap

March 23, 2017
Came out a little before 2000. It is clear with a slight breeze and 72 degrees with 88% humidity. I installed the ASI071MC-COOL upside down to match the orientation with the mount's controls. No FR, prime focus with the Lumicon DS filter.  After taking a few dark frames I noticed that the 
winds brought in clouds at 2026.   By 2200 the sky looked a little better with the sky meter reading was 18.43. Better than I expected with the clouds rolling through. It is somewhat clear now but high thin clouds are in parts of the sky.  As I've been hunting Herschel objects in Ursa Major, I decided to give Messier 81 a try with the new camera.

Messier 81, NGC 3031, Bode's Galaxy
The clouds held back and I got several 2 min exposures of M81. The raw subs were captured and included dark frame subtraction. The stacked exposure with 10 x 2 minute exposures (gain = 400, camera temp -10 C) looks pretty good but little detail in the galaxy's arms is evident.  This is a spiral galaxy about 12 million light years away


I had more issues with large dark circles forming on the images.  If I turn the camera's cooler off or at least set it to above 0 C, the circles disappear.  However they reform once I turn the cooler back on.   Clouds rolled in and ended the observing session at 2300 hours.
==

March 25, 2017
Surprisingly the skies are clear after heavy afternoon thunderstorms. The humidity is high so the seeing isn't great, but no clouds. Came out a little after 2000.  ASI071MC-COOL setup at prime focus with the Lumicon Deep Sky filter (2”). After about 30-45 min, I started getting the dark circle in the center of the ASI071MC-COOL's FOV. Cooling was on -10, so I turned it off and the circle disappeared.  At 2305 it is 62 F and 99% humidity with no wind and clear skies. Sky Meter reading = 18.92. Everything is wet!

H 160-2, NGC 3686
This is a small face on galaxy in the constellation Leo and is ~ 53 million light years from earth.   In the FOV with at least 2 other galaxies.  The image is 21 x 180 seconds at gain = 400.

The subject galaxy is nearly circular with a prominent bar running NS.  Off the N end there is an arm circling to the E and back around to the S.  From the S end of the bar is an arm circling W and back around to the N.  The second galaxy is a faint eliptical around 20 ' away to the ESE.  THis galaxy has no discerable core.  This is NGC 3691, a mag 12.4 galaxy that is 1.4 x 1'.   The third galaxy is also eliptical with a brighter core. It is ~ 15' to the NE.  This is  NGC 3684, a mag 11.4 galaxy that is 3.1 x 2.1 ' in size.  Galaxy cluster Abell 1264 is also in this frame but would require much more magnification to resolve.


H 21-1, NGC 3810
A face on spiral galaxy in Leo that resides approximately 50 million light years from earth.  The core is not overly bright.  Multiple 4 minute exposures was insufficient to pull out any detail.  I do note that the stars are a little elongated so apparently my guiding was lacking a bit.  Also the camera cooler was off as I was having issues with a dark circular region forming due to the high humidity.  The image is 8 x 240 seconds at gain = 400.  I'll have to try this object again to see if I can pull out any hint of the detail shown in the Hubble image.




March 31, 2017

Based on feedback from ZWO, I installed the auxillary desiccant tablets onto the camera a couple of days ago.  Hopefully that will dry out the air in the chamber housing the chip and avoid dew or ice formation.  They also advised to cool down the camera slowly.  I setup the ASI071MC-COOL at prime focus with the 2” Lumicon DS filter. I started the cooler at mild cooling 16 c and will stair step it down.


I tried to get M81 & 82 in the same frame but they were too close to the edge of the FOV, so I'll need to use the 2” FR to get both. For now I'll concentrate on M-81.  At 2318 sky meter reading was 18.94. Temp is 62 F with 96% humidity

Messier 81, NGC 3031, Bode's Galaxy
Decided to try this object again to see if I could pull our a bit more detail.  The image below is 5 x 360 seconds at gain = 400 and the camera is operating at -10 C.    The frames were stacked in SharpCap.  Uncharacteristically I used GIMP to adjust the brightness and contrast, which yielded an improved image. Perhaps I'll try using AstroToaster instead of SharpCap's to stack and adjust brightness and contrast next time.  I had no issues with dew or ice formation in the camera.



Poor tracking ruined my attempt at M-101.

Messier 13
Next I turned my attention to Messier 13 (NGC 6205), one of the finest objects in the night sky. It contains approximately 300,000 stars and resides 22,200 light years from earth. I stacked 11 x 60 second frames at -10 C and gain 400. I avoided blowing out the core, but the exposure needs to be a bit longer to reveal more stars.


I suffered a lot of dropped frames,  ~ 50% during this session.  Very frustrating.  Shut down at 0200

Saturday, June 3, 2017

First light for the ASI071MC-Cool

March 3, 2017

Came out a little after 8 pm on a cool(58 F), dry (40%), and clear night. First order of business is to test my Mallincam and ensure it is working. Then I'll hook up the new camera and give it a whirl.

I hooked everything up and the Mallincam was working and then it died. I noticed the dew controller showed low voltage also, so it appears to be my battery. I hooked everything up to AC power and it worked fine. I had just recharged the battery so either my battery charger is bad or the 6 year old battery is dying.

I'm using the Mallincam with only the 2” 0.75X focal reducer and Lumicon DS filter. This setup yields a 14.8 x 11.1 arcmin field of view (FOV).  I failed to install the heat sink so there is no cooling on the camera.   I took a 2 min image of M65 in Leo when it was 44 degrees up and it looked noisy but otherwise good. I stacked 5 x 3 minute images to reduce the noise. The autoguider is working wonderfully, no image shift or enlongated stars ! The stacked image is pretty good with some detail in the galaxy visible. If I had the fans of to cool the sensor it would be a bit cleaner. Now to switch to the new camera.


Setup the ZWO ASI071MC-Cool camera with the 2” 0.75x focal reducer and 2” Lumicon DS filter.  I found focus at 37 mm.  I fired up SharpCap and setup with a gain of 400 and focused on Denebola. I then went to M65 and took a 120 sec image with no cooling,


WOW, a really nice image for first try.   The FOV is enormous and the corresponding image scale is small.  As a result you can't see as much detail in the new camera's image.  I uploaded the image to astrometry.net and it calculated a FOV of 52.4 x 34.8 arcmin.   This is 3.4 X larger FOV than with the Mallincam.   I played a bit with the image adjustments in SharpCap, but I have more to learn in this area.

I turned on the cooler and set it to -20 C. It quickly achieved this temperature. I can't really tell any significant difference in the noise.  I took 3 x 5 minute exposures and stacked them in SharpCap

The images are blue despite my adjustments of the histogram. I need to learn to better use the white balance & hue adjustments. The stack of 5 min exposures doesn't reveal as much detail as the Mallincam did until you zoom in.  This camera is quite impressive.

More perplexing than the blue tint of the image is the black triangular structure on the left side of the image and the cross-hatched pattern through the image.  These appear to be related to the cooling.

I moved the scope over a bit to see if I could capture the Leo Triplet.  With my Mallincam I could never get this FOV to catch this collection of galaxies.  With the gain still at 400 and the sensor cooled to -10 C, I took 3 minute exposures and centered the galaxy trio.  There they were; M 65 at the bottom left, M 66 at the top left, and the edge on NGC 3628 at the top right.   I was able to adjust the white balance and histogram to get a nice black field.  I then stacked 8 x 180 second exposures.  What a nice image !  It is wonderful to have the resolution to enable significant zooming in to reveal added details.  This is why I bought this camera.  Astrometry.net measured this image as 52.3 x 34.8 arcmin.



I'm not sure what causes the band at the top of the image.  Actually it appeared as a lightening at the bottom of the frame in the SharpCap preview.  I'll experiment with this more next time.  I shut down at 1:30 am – a nice first night with the new camera.

Wednesday, May 3, 2017

New Camera !!

I've had my Mallincam Extreme II for nearly 5 years and it has provided me many fantastic views of the universe.  Without it I probably would not still be interested in astronomy as viewing faint, colorless, fuzzy patches through an eyepiece is not very interesting to me.   As chronicled in this blog, the Mallincam coupled with a Lumicon Deep Sky filter, has enabled me to see many iconic celestial objects from my light polluted suburban backyard with ~ 4.8 Naked Eye Limiting Magnitude.

My astronomy interests are still aligned with video astronomy / electronically assisted astronomy.   I enjoy sitting out with my scope and viewing objects in near real time.   I have no ambitions to be an astro imager as spending hours post processing images is not my idea of fun.  I have desired to improve the quality of my images so I could discern more details in the objects I view.  So I started studying new cameras.  My criteria were;

1.   One Shot Color
2.   Cooled to reduce noise
3.   Decent sensitivity to see DSO with exposures < 4 minutes
4.   Sufficient resolution to provide detailed views (I arbitrarily set minimum of 6 megapixels)
5.   Large chip to provide a good field of view (at least 20 x 15 arc minutes at prime focus)
6.   USB camera for both control and image download with 1 cable
7.   2" aperture minimum
8.   Price of <= $ 1,500 US

I looked at several brands and quickly focused in on the new offerings by Mallincam, Atik,  and ZWO.  After reading posts on Cloudy Nights and the Video Astronomy Forum I zeroed in on the new ZWO ASI071MC-Cool.   It hit all of my criteria and my wife purchased it for me as a retirement present.

On March 2, 2017 I received a ZWO ASI071MC-Cool today from Agena Astro.  It looks to be a beautifully made camera.  Pictures of the unboxing were uploaded to my Flickr account.  I downloaded version 2.9 of SharpCap and installed the camera's native driver from the website. I fired up SharpCap and plugged in the camera into a USB port and the camera was sensed by the software where I could select it. I was able to take a couple of dark images (lens cap on) of varying lengths.  I cracked the lens cap and saw light in the image, so I know that the camera is talking to the software. I look forward to first light for the new camera in the observatory.

Sunday, April 30, 2017

February 2017 Observing Report


Feb 16, 2017
Has been quite cloudy and stormy of late so I haven't been able to view. This is a work night but this weekend is not projected to offer good weather and tonight does, so here I am. It is cold and dry with temps in the upper 40s and humidity in the 55% range.  I will setup again with the full MFR-5, 50 mm ext tube, 1”focuser ring, and 2-1-1/4” reducer for a F 4.43.  This setup give my Mallincam XT-418 a 20.6' x 15.45' FOV.  I may try adding a spacer or two later on to test the FOV change and vignetting & coma effect.  Standard setup, AGC = 6, APC = 0 , ATW, Gamma = 1.0, cooling set to -5C.  I have the Lumicon Deep Sky filter on.

My tracking is horrible with image shift after 40 sec images.  I found the w azimuth lock bolt was loose so I tightened it.   I need to spend some time polar aligning and getting my guiding scope operational.  However for now I want to knock out a few objects.  The constellation Cassiopeia is nicely oriented so I'll concentrate on the Herschel 400 objects in that constellation.

Herschel object H 35-6 (NGC 136) is a small tight cluster of ~ 15 stars in nearly circular pattern The SE corner has a straignt line of 3 stars running NNE to SSW that are brighter than the other stars in the cluster.  The cluster looks almost like Scorpius with the 3 stars and then to the NW is a curving tail that bends to the SW.  Following this line of stars to the SW .

H 78-8 (NGC 225) is a large OC of around 2 dozen stars that are much larger and brighter than the background stars.  The stars are arranged in an amorphous pattern with a 6 star wavy line at top running E to W.



H 159-1 (NGC 278) is a small face on spiral galaxy.  At only 2 arc minutes in size, the image scale is rather small.  I would do better without a focal reducer and perhaps with a Barlow.  I am only seeing the object at ~ 1' in size.  It is however unmistakable as a galaxy.  I would note that even the Deep Sky Survey image of this galaxy reveals little structure. 



H 64-8 (NGC 381) is an open cluster in a rich star field.  There is a line of over a dozen stars running ENE to SSW.  The cluster is comprised of > 3 dozen stars and one that is brighter than the rest & larger




H 45-7 (NGC 436) is a small triangular shaped cluster of around 2 dozen stars.  
The triangle points to the center star of a 3 bright star line to the NW.   The line runs NNW by SSW. There are long curving lines of stars extending from the cluster to the SW, SSW, and S.


H 42-7 (NGC 457) is a bright cluster consisting of two quite bright stars and a spinal run of stars with appendages off to the top and bottom.  
The spine consisting of 15 - 20stars runs NW to SE.  The top "eye" star is the largest and has 5 small stars arranged into a square to the star's E.  The third brightest star in the group is in the top appendage, which runs N.  The southern appendage "arm" or "wing" is 2 stars wide and curves to the W.  Whether you see a dragon fly or ET, this is a nice cluster.  First a short exposure to show only the bright stars of the cluster.

and a longer exposure for a deeper view.


H 48-7 (NGC 559) is 
a broad convex line of stars running SW to NE through the FOV.  In the SSW is a line of 6 stars running NW to S.  The cluster is roughly spherical and sits near the apex of the convex line.  It is comprised of a couple dozen stars,  many fainter than the stars comprising the convex line.  The surrounding star field is rather sparsely populated.


H 49-7 (NGC 637) is 
a cluster with hard to recognize boundaries.  There are 4 brighter stars and 10-16  smaller stars in a roughly circular patter.  There is a line to the E that curves toward the SE that is comprised of around 15 stars.  At the end of the line is a concave semi-circle of 5 stars.  The FOV includes 2 bright stars to the NNW of the cluster and one to the SE.  There is also a larger star just on the edge of the FOV to the WSW.  is rather sparse of stars but there one to the SW that is bigger than any in the cluster

H 46-7 (NGC 654) is 
a bright large star with a cluster of > 2 doz much smaller stars to the SE.  From the bright star there is a z shaped line that leads to a long line of 9 stars extending to the NNE .  There are few stars to the E of the cluster, but to the W is well populated.


H 65-8 (NGC 659) is another cluster with hard to discern boundaries as it is in a rich star field.  9 bright stars litter the core of the cluster with many faint stars surrounding.  There are many other stars to all directions.


H 31-6 (NGC 663) is a broad cluster of nearly circular proportions comprising some    20 or more stars. The star field is sparse to the E of the cluster but full in all other directions.  


With a shorter exposure depicting only the brighter stars you can see 4 "rays" emanating from a point on the southern edge of the cluster.


H 66-8 (NGC 1027) is a cluster comprised of around 10 bright stars in a very dense star field.  There is a central star that is much larger and brighter than the others.  As is often the case with me, I have insufficient artistic abilities to describe a shape in this cluster.

I completed all the Hershel 400 objects in Cassiopeia !  A very productive night.   It is late for a work night and I'm shutting down at 2326.


Feb 22, 2017

Came out at 6:45 on a warm clear night, very unusual for February. Set up with the Mallincam at prime focus and worked on getting the polar alignment better. Using standard camera settings: AGC = 6, APC = 0, gamma = 1. Got the scope polar aligned with the polar scope as best I could and then performed a drift alignment on Mirzam (front foot of Sirius) and then Mirach.

I left the camera at prime focus (11.4 x 8.5 arc min FOV) with no filter and jumped into viewing Hershel objects in Leo. First object NGC 3227 and I'm seeing significant image shift between 1 minute exposures. Very disappointing.  Apparently my drift alignment procedure is not as sensitive as imaging.  I had hoped to avoid guiding in my setup but it looks like that will be needed, especially at prime focus.  I'll hit a few of the brighter targets tonight and work on the autoguider and software next session.

H 29-2 (NGC 3227 & 3226) is a pair of interacting galaxies (ARP 94).   The two galaxies have cores of similar size and brightness but the galaxy on the lower right (NGC 3227) is more face on, bigger, and elliptical.  The long axis is towards the smaller galaxy. The smaller galaxy (NGC 3226) appears to be more circular.  I can't discern the outer edges of the two galaxies at this exposure level and tracking is insufficient to allow a longer exposure.  Would be a good object to revisit when I get the autoguider going.

H 50-2 (NGC 3607 and 3605) is another pair of galaxies although these two are not interacting.  The larger one (NGC 3607) is elliptical  with a halo that is a couple of core diameters wide.  The smaller galaxy (NGC 3605) is at the 2 o'clock position to the larger one  It appears to be more elliptical.   NGC 3608 is just out of the FOV to the S of NGC 3607.

Packed it in around 10:45. Next time I'll fire up my Orion Awesome Autoguider to address the poor tracking


Feb 25, 2017
Set up with the 2” FR + MFR-3 for a FOV of 18.6 x 13.9' and F 4.91 and the 2” Lumicon DS filter. I also setup the Orion guide camera tonight to see if I can improve my tracking.   After climbing the learning curve with the autoguider &PhD2, I found the guiding to work quite well as I was able to take 120 second images and stack them with well shaped stars.  This is a huge improvement in my capability to capture faint details in objects.  Continuing with the Herschel 400 object hunt.

H 27-1 (NGC 3412) is a nearly face on elliptical galaxy oriented NW to SE.  There is a bright core and the halo extends 1 core diameter to each side and 2-3 diameters to the NW & SE. No details in the halo are discernible.   The galaxy resides in a nice star field of all similarly sized and brightness stars.


H 44-2 (NGC 3190) is a near edge on galaxy oriented Nw to SE with a bright core visible on the SW side.    there is a prominent dust lane running just below the visible core.  A remarkable FOV with 2 other galaxies visible and another just at the southern edge of the FOV.  This is the Hickson 44 compact group.  

Sky meter reading at 0048 = 18.97 at 55 F with 50% humidity.  Shutting down for the night.