Adventures in suburban backyard astronomy in the 21st Century
Thursday, November 2, 2017
May 2017 Observing Report
May 1, 2017
Came out around 2130 on a clear warm night. Setup the scope again at prime focus using 4” of focuser rings and both the Lumicon Deep Sky and the Badder UV/IR filters. Used the SharpCap Bhatinov mask focusing aid to bring in the focus @ 35 mm and then synced the model on Arcturus. I cleaned both filters so hopefully I got rid of that dark circle in my images last night. Earlier today I down loaded the newest Sharpcap 3.0.3855.0 . Will see how it works tonight. At first look, it is virtually identical other than a few new options like flat creation and subtraction. Not thrilled that in order to do dark field subtraction I have to buy the license. At 10 British pounds / year it isn't that much money, but a trial period would have been nice.
H28.1-4 NGC 4038 & 4039 – Antennae galaxy (ARP 244)
A wonderful enigmatic object. Two interacting galaxies (NGC 4038 & 4039) in what looks like a larva with a circular head. There are 4 bright regions in the tail section and 6 or more in the circular head. There is only a hint of one of the wispy curving extensions that are shown in more detailed photos. The FOV contains 2 bright stars and > 2 dozen fainter ones.
Took a set of 4 min images. The light curve maxima is still only around 15%, so not a lot of signal even at 240 seconds.
Stack of 8 x 240 seconds, AGC = 400, camera at -10 C, dark frame subtracted
crop of above image
At 0049 it is 57 F with 98% humidity. Sky meter reading is 19.11.
H 587-2, NGC 6426
A smallish (~ 2 ') GC in the constellation Ophiuchus approximately 67,500 light years from earth. The GC is roughly circular shape. There are only around 8 discernible bright stars in the GC core and many fainter ones. The FOV is well populated.
stack of 5 x 180 seconds, gain = 400, chip temp = -10, dark frame corrected
crop of above image
This target would have benefited from longer exposures and more frames but even with targets that are 37 deg high and 110 in azimuth I am experiencing guiding performance in both axis!
I'm now getting a dark circle in the middle of the image that is obscuring the target !! ARGH !!! Turned cooler set point to 0 and then 10 to thaw it out. This is really frustrating. I know it is damp out but with the descant tabs the chip should stay dry enough to not fog over. I have the dew shield on the scope so the scope should not be fogging over.
H 72-8, NGC 6633
A nice bright OC in the constellation Ophiuchus consisting of about a dozen brighter stars and many fainter ones. The central area is an oval in the SW to NE orientation. To the SW are 2 curving lines of stars; one curves to the WSW and onto the SE. On the NE end of the oval is an a 5 dice pattern with a double star at the lower right position. To the N of the cluster is a semicircle of 6 stars, concave to the cluster. The star field is densely populated.
stack of 7 x 120 seconds, gain = 400, chip temperature = 0 C, dark frame corrected
I noted the guiding was much better on this target but still not great.
H 41-1, NGC 6514, Messier 20, The Trifid Nebula
A beautiful red nebula with dark lanes running through it. Some faint blueish nebulosity (a reflection nebula) is visible W of the main red emission nebula where a bright star resides. The star field is densely populated. The main nebula is roughly circular and quite large. I've seen this object before and imaged it with my Mallincam, but I've never seen it in this detail. Luckily the guiding held the stars quite round for a stack of 11 x 3 min. The best looking image I've taken with this ASI071MC-Cool camera. I didn't have a dark frame for 0 C, so there is some lightening along the bottom of the frame due to amp glow.
stack of 11 x 180 seconds, gain = 400, chip temperature = 0 C, no dark frame correction
This object is quite bright (apparent magnitude of 6.3) such that even a single 180 second exposure yields a reasonable image.
single 180 second image, gain = 400, chip temperature = 0 C, no dark frame correction
I shut down at 0243.
May 6, 2017
Came out at 2030 on a nice clear night. Hope to catch Jupiter and the GRS before it gets too close to the moon. Will be my first attempt at planetary with the ASI071MC-COOL camera. Set up at prime focus again with the Lumicon DS & Badder UV/IR filters on. This setup yields a Field of View (FOV) of 40.4 ' x 26.8'.
I took several hundred images of Jupiter and stacked them in Registax, but the stacked images were no better than the singles. The seeing just wasn't good enough for detailed planetary imaging. I'll have to try again on a better night.
Resumed my Herschel 400 project. Camera still at prime focus with both filters in place.
H 19-6, NGC 5897
A GC with many discernible stars in the core. Most stars in the core are of similar size but a few are larger. The GC is roughly circular. It resides in a densely populated star field with 1 bright star to the W of the GC. To the SE of the cluster is a convex semi-circle of stars.
Note the histogram on SharpCap couldn't be balanced so it is a bit greenish and lacking in red. I haven't had this issue before. Possibly influence from the near full moon.
stack of 7 x 3 min, gain = 400, chip temp = -10 C, dark frame subtraction
At 2327 readings are 57 F, 88% humidity, no wind. Sky Meter reading = 17.72 with a > 50% moon just past zenith.
H 280-1, NGC 6217
A small (approximately 3') galaxy in the FOV. It appears to have a strong bar running NW to SE with a bright star just SE of the core. No detail is discernible in the halo A well populated star field . There is an asterism to the WSW of the galaxy that resembles the triangular shape of a pine tree.
stack of 10 x 3 min, gain = 400, chip temp = -10C, dark frame subtraction
Due to the size of this object, it would be better to use a barlow, but I doubt my seeing would have supported such magnification. Stacking and cropping and then inverting the image, the shape of the galaxy is better viewed..
stack of 10 x 3 min, gain = 400, chip temp = -10C, dark frame subtraction, cropped & inverted
With NGC 6217 I'm still having a green hue to the images in SharpCap. I'm able to adjust in AstroToaster but I'm curious why this is happening.
H 215-1, NGC 5866, Messier 102
My observation matches the NGC 5866 pics and description in Wikipedia and other online sources but differ from what is in Deep Sky Planner and the DSS pic. An edge on galaxy with a bright core region on both sides of the dust lane. The galaxy is surrounded by 2 bright stars, one to the E and one to the W of the NW edge of the galaxy. The galaxy is in the constellation Draco and lies 50 mly from earth.
stack of 10 x 3 min, gain = 400, chip temp = -10 C, no dark frame subtraction
crop of the above image
H 195-2, NGC 6287, Melotte 163
A tight GC with a bright core. Many individual stars are discernible around the core. While the GC is circular, there are more stars to the NE & SW with fewer on the NW & SE sides. The GC is in a very dense star field so its boundaries are had to determine. It lies at a distance of 30,300 ly from earth.
stack of 7 x 3 min, gain = 400, chip temperature = -10 C, no dark frame subtraction
Shut down at 0211. The equipment worked well except for the greenish color hues apparently due to the full moon.
May 25, 2017
Tonight is clear and low (for SE LA) humidity and the new moon, so I had to come out for awhile. Set up the ASI071MC-Cool at prime focus again with the Lumicon DS & Badder UV/IR filters on. This setup yields a FOV of 40.4 x 26.8 arc min.
My laptop is a Dell Inspiron 1764, CPU I3 M330, 2.13 GHz, RAM 4 GB, HD 454 GB, OS Windows 7 64 bit Home . The USB ports are all USB 2 while the camera is USB 3. I'm still having trouble with dropped frames and partially loaded images. This is very frustrating, especially late at night. I had the Turbo USB speed in SharpCap set at 40 but after some experimentation I increased it to 100. With the Turbo USB at 100 I didn't suffer any dropped frames although I did have several that only partially loaded into SharpCap. Not sure if that is a camera or SharpCap issue.
H 165-1, NGC 4151
A small (~ 5') circular galaxy with a large bright core. The halo extends 2-3 core diameters in all directions. There is no structure evident in the halo. The galaxy is bounded to the E & SW by 2 stars of similar brightness & size. There is a large reddish star to the S. There is a smaller elliptical galaxy to the NE of NGC 4151. It has a bright core and the halo extends 2 core diameters to the E & W and 3 core diameters to the N & S. No structure is evident in the halo. Unfortunately the images only partially loaded into the computer - ARGH !@#%&*#$ Will have to image this object again.
H 176-1/ H 177-1, NGC 4656/4657, The "Hockey Stick" galaxy
An intriguing galaxy that is long and slender running NNE to SW. It is broader and fainter on the SW end and on the NNE end the galaxy is bent NNW, hence the name "hockey stick galaxy". The deformation is due to interaction with neighboring galaxy NGC 4631. The Hockey Stick is slightly brighter near the middle but there is no discernible core. There is what appears to be a star near the middle SE side. In the NE half there is a bright nodule at the point that the galaxy's "arm" bends N. The star field is relatively spars in the immediate vicinity of the galaxy but there are stars surrounding it.
stack of 8 x 3 min, gain = 400, chip temp = 0 C, no dark frame subtraction, cropped
I didn't guide on NGC 4151 and yet the images looked fine. I did guide on NGC 4656 and the guiding was good, no spurious peaks. At 2301 the sky meter reading was 18.96. It is 66 F and 83% humidity. A nice night considering it is nearly June. Shut down at 2310.
May 26, 2017
Came out a little before 2100 on a clear dark night with unseasonably dry conditions. I cleaned both filters well before this session to hopefully avoid the distortions observed last night. NOTE: this did work as the textile pattern was not observed even when greatly stretching the data.
I had to rebuild the mount model as I accidentally hit cold start on the Gemini hand controller– argh ! Amazing the download speed with the TURBO USB set to 100%. Rarely does an image go beyond a second or two past the exposure time.
Returned to NGC 4656 to capture a better image the first 3 min image was dropped - @@*&#%! Second image came up with a large black spot in the middle of the FOV ! Cooler is at -10, so I backed off the cooling to 0 and then 5 C. I had cooled the sensor down very slowly, irritating the difficulties I'm having with this.
I couldn't get to NGC 4656 without the camera coming too close to the pier, so I changed to M 57. The black spot has gone as I had warmed the camera to 5 C. I tried cooling it back to -5 and the spot returned so I went back to 5 C. I captured 2 light frames and then lost the next 5! Very frustrating! I don't know what to do about this other than get a laptop with a USB 3 input and hope that resolves the issue. I collected 10 light frames and 5 dark frames.
stack of 10 x 3 min, gain = 400, chip temp = 5 C, dark frame subtracted in AstroToaster
At Turbo USB = 100 I still see some redish lightening at the bottom of the frame, but not as bad as it was with Turbo USB = 40.
At midnight the sky meter reading was 18.82. It is 72 F & 99% humidity. Much more humid than last night. Clouds are gathering in the west. Shut down for the night.