New Astrocamera on the bench in test

ZWO ASI1600mm Pro Camera with
EFW 8-position Filter Wheel

It's been about 2 years since I purchased my QHY10 OSC (One Shot Color) camera and I've taken a number of nice astrophotos with it, both at the prime focus of my EdgeHD as well as on the Hyperstar wide field lens. But the "real-deal" in astrophotography is though the use of mono (black and white) cameras. In the OSC case, the image is taken in color, much like a normal digital camera. In this scenario, the light must pass a filter in the camera known as a Bayer Matrix, which consists of alternating red, green (2x as many as red and blue) and blue filter elements. A given sensor therefore contains 25% red sensitive pixels, 50% green pixels and 25% blue. So the light from a object in space is split into these groupings. What this means is that a predominately red object is only captured by 25% of the pixels on the sensor (and lots of deep space objects tend to be in the red end of the spectrum). Much of the sensor is wasted and the sensitivity is greatly reduced.

A mono camera captures all the light all the time. That means it is much more sensitive and captures a lot more data in any given exposure. But if its mono, how do you get a color photo?

Astrophotographers use a set of colored filters to achieve a final image. Four separate exposures are necessary to create a single color photo - one through a red filter, one through a green, one through a blue and finally one through a clear, or luminance, filter. These are then combined later in software post processing to produce a color image. So the time on the telescope is quadrupled when imaging with a mono camera, but the results are of greater quality and capture much more detail in the dim regions of an object.

So I've been spending some time testing and getting the software set up to handle the new camera while the skies are cloudy. The photo shows the ASI1600mm Pro being tested with it's filter wheel attached. Much to do as I hope to test it out on real space objects in the coming days.

Follow the bouncing "Universe"!

 

An interesting theory now proposes that the universe didn't come from a colossal explosion (the Big Bang) but rather as the result of a cosmic bounce - a collapsing universe reaches a point where it bounces back and starts expanding again.

The theory is rather interesting, and doesn't need the controversial 'inflation' part of the popular Big Bang theory.

Read more at:  Quanta Magazine

Fundamental physics is frustrating physicists

Science and technology

Jan 13th 2018

No GUTs, no glory ...

DEEP in a disused zinc mine in Japan, 50,000 tonnes of purified water held in a vast cylindrical stainless-steel tank are quietly killing theories long cherished by physicists. Since 1996, the photomultiplier-tube detectors (pictured above) at Super-Kamiokande, an experiment under way a kilometre beneath Mount Ikeno, near Hida, have been looking for signs that one of the decillion (10³³) or so protons and neutrons within it (of which a water molecule contains ten and eight respectively) has decayed into lighter subatomic particles.
That those tubes have, in the more than 20 years the experiment has been running, failed to do so is a conundrum for physics, and one that is becoming more urgent with every passing month.

For the complete story head on over to The Economist

Geminids Meteor Shower Tonight

If you had to pick one night for watching the 2017 Geminid meteor shower, it’d probably be December 13 (morning of December 14). The nights before and after should be good as well. On a dark, moonless night, the Geminids are known to produce 50-120 meteors per hour, or nearly 1-2 meteors per minute. This year, with the Geminids’ parent object – 3200 Phaethon – nearby, you might see more. Plus, the moon is in a waning crescent phase for this year’s shower; it won’t interfere, and it’ll be passing some predawn planets.

Check out EarthSky for the top 10 tips for watching this shower. 

NGC 7000 - The North America Nebula

During the later part of November when we had some nice run of clear, moonless nights, I imaged a lot of DSOs (Deep Space Objects).  Finally got around to processing NGC 7000.

The North America Nebula (NGC 7000 or Caldwell 20) is an emission nebula in the constellation Cygnus, close to Deneb (the tail of the swan and its brightest star). The remarkable shape of the nebula resembles that of the continent of North America, complete with a prominent Gulf of Mexico. It is sometimes incorrectly called the "North American Nebula". The North America Nebula is large, covering an area of more than four times the size of the full moon; but its surface brightness is low, so normally it cannot be seen with the unaided eye. Binoculars and telescopes with large fields of view (approximately 3°) will show it as a foggy patch of light under sufficiently dark skies. However, using a UHC filter, which filters out some unwanted wavelengths of light, it can be seen without magnification under dark skies. Its prominent shape and especially its reddish color (from the hydrogen Hα emission line) show up only in photographs of the area. The portion of the nebula resembling Mexico and Central America is known as the Cygnus Wall. This region exhibits the most concentrated star formation. (Wikipedia)

NGC 7000  -  November 20, 2017
EdgeHD11 w/Hyperstar and QHY10 Camera
30x180sec subs at f/2

I had imaged this object with my William Optics 102mm APO, but the EdgeHD11 with Hyperstar lens really pulls out the detail.  There is however, some issues with my setup of the Hyperstar.  If you look closely at the top left of the image the stars are actually small donuts; at the bottom right they are pinched. I'm pretty sure this is an issue with the camera not aligning properly to the Hyperstar lens; something which I have struggled with in the past to correct.

Cars in Space - you bet!

Elon Musk  (SpaceX) tweeted a few days ago:

"Payload will be my midnight cherry Tesla Roadster playing Space Oddity. Destination is Mars orbit. Will be in deep space for a billion years or so if it doesn’t blow up on ascent."

Yikes - a Roadster in orbit!

Complete story at: Elon Musk - Roadster to Mars

Equivalence principle passes another test

A team of researchers from the French Aerospace Lab and at the Côte d'Azur Observatory working on France's MICROSCOPE satellite project has further confirmed the equivalence principle by recreating Galileo's free-falling objects experiment in a satellite.


Read more at: PhysOrg

Talk about Quality Engineering ...

If you tried to start a car that's been sitting in a garage for decades, you might not expect the engine to respond. But a set of thrusters aboard the Voyager 1 spacecraft successfully fired up Wednesday after 37 years without use.

An artist concept depicting one of NASA's twin Voyager spacecraft. Humanity's farthest and longest-lived spacecraft are celebrating 40 years in August and September 2017. The Voyager team is able to use a set of four backup thrusters, dormant since 1980. They are located on the back side of the spacecraft in this orientation. Credit: NASA/JPL-Caltech.

Voyager 1, NASA's farthest and fastest spacecraft, is the only human-made object in interstellar space, the environment between the stars. The spacecraft, which has been flying for 40 years, relies on small devices called thrusters to orient itself so it can communicate with Earth. These thrusters fire in tiny pulses, or "puffs," lasting mere milliseconds, to subtly rotate the spacecraft so that its antenna points at our planet. Now, the Voyager team is able to use a set of four backup thrusters, dormant since 1980.

See the complete story at: JPL

The Seven Sisters (Pleiades) Star Cluster

Early Thanksgiving day morning I imaged a favorite star cluster of mine, the Pleiades or Seven Sisters. The Pleiades, also known as Messier 45), are an open star cluster containing middle-aged, hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky.  The cluster is dominated by hot blue and extremely luminous stars that have formed within the last 100 million years. Dust that forms a faint reflection nebulosity around the brightest stars was thought at first to be left over from the formation of the cluster (hence the alternative name Maia Nebula after the star Maia), but is now known to be an unrelated dust cloud in the interstellar medium, through which the stars are currently passing. (Wikipedia)

M45 (The Pleiades) - Nov 23, 2017
WO-GT102 and QHY10 Camera
30x300sec Subs at -20C  - f5.5

This image is a processed stack of 30, 5 minute subs, taken with my WOGT102mm APO refractor and QHY10 camera.

New Images

I just noticed that a good portion of my past images have not had the correct dark frames processed on them. This means that thermal noise from my camera was not getting subtracted out. Granted the QHY10 operating at -20C doesn't produce a lot of thermal noise, there is still some there and it should be removed.

Adjusting for the new parameters in PixInsight I re-ran the M33 image taken with my WO GT102 APO. The image is a little darker, but the noise is greatly reduced. I may decide to reprocess some of my past images to allow for this improvement.

Updated M33 with Dark Frame Subtraction

On November 24, 2017, I placed my main telescope on automatic and scripted it to take ~3.5 hours of NGC 891, an edge on spiral galaxy while I got some needed sleep :).  Results were really good. 44 subs, each 300 seconds long were taken in the wee hours of the morning. Here is the end result of that session.

NGC 891, Nov 24, 2017
EdgeHD11 at f7.0 - 44x300sec subs with QHY10

NGC 891 (also known as Caldwell 23) is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. The galaxy is a member of the NGC 1023 group of galaxies in the Local Supercluster. It has an H II nucleus.

Back in business

A few nights ago my main telescope mount started to act erratically. It would swing uncontrollably in the RA axis and resetting power didn't help.  Thinking the worst - a bad motor control board or motor, I removed the RA motor and tested it out.  Sure enough, when the RA motor was connected to the DEC axis the problem occurred. The issue is definitely correlated to the motor.

I contacted Ed at DeepSpaceProducts for the availability of a new motor. after describing the issue to him he suggested I first open the motor's encoder casing and check to see if the encoder assembly is OK since it sounded like an encoder problem to him. I found that the encoder disk was loose. Once tightened the issue was resolved. That saved me about $180. And, as usual, Ed is more interested in getting his customers back in business than he is just selling product.

Testing on real imaging last night reveals that the RA motor is fixed.

Not to waste a clear night, I set up the William Optics 102mm APO to capture some galaxies. Here is M33, the Triangulum Galaxy, also known as the Pinwheel Galaxy.

The Triangulum Galaxy is a spiral galaxy approximately 3 million light-years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC 598. The Triangulum Galaxy is the third-largest member of the Local Group of galaxies, behind the Milky Way and the Andromeda Galaxy. It is one of the most distant permanent objects that can be viewed with the naked eye.

M33 - Nov 22, 2017
WO GT102 - F/5.5 29x300sec QHY10 Camera