Sweet Serendipity

Earlier this year, I upped my astrophotography game. I purchased a monochrome camera and a stack of color and narrow-band filters. Of course, I needed to leave the area to test my new equipment. Surprisingly, the prettiest pictures were not taken with my new equipment or huge scope. Instead the best shots were acquired with my oldest (and least expensive) equipment.

I chose the ZWO 1600 Mono Cooled because of its relatively wide field of view for the price. Likewise, having previously worked with the ZWO ASI224MC planetary camera, I felt familiar with the product and software (or so I thought.) With a new filter wheel and seven different filters, I was ready to conquer the world of monochrome and narrow-band imaging.

ZWO 1600 Camera attached to my Meade LX-850

Zwo Motorized Filter Wheel

Of course Maryland nights in March are notoriously schizophrenic. This year was no exception. Every moonless night, clouds filled the sky. So, I again made plans to meet a friend in Southern Georgia, packed my scope into the tiny Fiat 500 and braved the treacherous lanes of I-95 South.

Although never-ending lane closures in South Carolina delayed my arrival, The Stephen Foster State Park greeted me with crystal skies. My exhaustion dissolved as I saw a beautiful cone of the Zodiacal Light over The Okefenokee Swamp. I jumped out of my vehicle and immediately set my scope up next to my friend’s newly-purchased Meade LX-850.

While the telescope's temperature equalized to the chilly night air, I set up a Canon 60D on a steady tripod, pointed it toward Orion and allowed it to take 30 second exposures until the battery expired. Although my makeshift dew shield interfered as the breezy swamp air flowed by, I like the results. I had never attempted video astrophotography. Clearly, we positioned ourselves on the busy air corridor between Florida and the Northeast.

Deep sky astrophotography still challenges me with the paltry number of images obtained on a given night. Now that I would be imaging each object in multiple wavelengths, I planned to observe only a few  objects each evening.  The first two nights of the trip, I planned to observe only seven deep-sky objects. Between nebulae and galaxies, I would attempt to image a few of the Gas Giants’ irregular satellites

NIGHT 1

Object                     Total        File          Total        Description             

                                Time        Type        Images

Venus                      10 mins.  .AVI         4000        One Video of Each  Luminosity/Red/Green/Blue Filters

Mercury                  10 mins.  .AVI          4000        One Video of Each  Luminosity/Red/Green/Blue Filters

Flats                        30 mins.  .FIT          25            Five exposures of each- Luminosity/Red/Green/Blue/H-Alpha Filters

Horsehead Nebula 150 mins. .FIT          30            Six 5-minute exposures of each - Luminosity/Red/Green/Blue/H-Alpha Filters

Contingency Dark    5 mins.    .FIT          1              Single 5-minute dark while slewing

Cone Nebula           100 mins. .FIT          20            Five  5-minute exposures of each - Red/Green/Blue/H-Alpha Filters

Contingency Dark    5 mins.    .FIT          1              Single 5-minute dark while slewing

JIV – Himalia           15 mins   .FIT          3              Three 5-minute exposures of outer Jovian satellite – Luminosity Filter

JIV – Elara               15 mins   .FIT          3              Three 5-minute exposures of outer Jovian satellite – Luminosity Filter

Ringtail Galaxy        100 mins. .FIT          20            Five  5-minute exposures of each – Luminosity/Red/Green/Blue Filters

Contingency Dark    5 mins.    .FIT          1              Single 5-minute dark while slewing

S IX - Phoebe           15 mins   .FIT          3              Three 5-minute exposures of outer Saturnian satellite – Luminosity Filter

NIGHT 2

Object                     Total        File          Total        Description             

                                Time        Type        Images

Flats                        30 mins.  .FIT          25            Five exposures of each- Luminosity/Red/Green/Blue/H-Alpha Filters

Orion Nebula          150 mins. .FIT          30            Six 5-minute exposures of each - Luminosity/Red/Green/Blue/H-Alpha Filters

Contingency Dark    5 mins.    .FIT          1              Single 5-minute dark while slewing

Rosette Nebula       60 mins.  .FIT          20            Three  5-minute exposures of each - Red/Green/Blue/H-Alpha Filters

Contingency Dark    5 mins.    .FIT          1              Single 5-minute dark while slewing

M104                       100 mins. .FIT          20            Five  5-minute exposures of each – Luminosity/Red/Green/Blue Filters

JIV – Himalia           15 mins   .FIT          3              Three 5-minute exposures of outer Jovian satellite – Luminosity Filter

JIV – Elara               15 mins   .FIT          3              Three 5-minute exposures of outer Jovian satellite – Luminosity Filter

M87                         100 mins. .FIT          20            Five  5-minute exposures of each – Luminosity/Red/Green/Blue Filters

Contingency Dark    5 mins.    .FIT          1              Single 5-minute dark while slewing

S IX - Phoebe           15 mins   .FIT          3              Three 5-minute exposures of outer Saturnian satellite – Luminosity Filter

Knowing that I would be working with these images for the next few months, I needed a way to leave Georgia with more images on my hard drive.

I had an idea.

The LX-850 must be balanced on three axes. Not only must the operator balance the right ascension axis with the huge counterweights, the declination axis must be perfectly balanced as well. Unfortunately, the scope is designed to be intrinsically out of balance. The plate to which the heavy Optical Tube Assembly has more metal on one side.  A counterweight is provided to offset that difference. However, the counterweight over compensates. In order to achieve perfect balance, something must be placed on the opposite side of the counterweight.

LX-850 Mount. Left side of mounting plate is much larger than right side.

I decided to attach my modified Canon Rebel XS DSLR camera and 90mm Pro Optic scope to balance the counterweight. Programing the camera to take five-minute exposures throughout the night, the Canon would serendipitously image the objects the main scope pointed toward. I realized that many of the images would be smeared as the scope slewed to other objects or I centered objects in the main field of view. However, some exposures should capture wide-angle views of the objects I imaged.

LX-850 with 90mm Pro Optic

Maksutov-Cassegrain and Modified Canon Rebel DSLR acting as Counterweight

Primary observing did not go well on either night. The New ZWO 1600 seemed to randomly choose its own exposure times leaving many of my images underexposed. Likewise, the camera seemed often to forget it was able to cool itself marring my images with noise. When everything seemed to be going well, I discovered the camera had forgotten that it had a filter wheel. The exposures that seemed be taken in red, green and blue light actually were only captured with one filter.

As Mercury was retrograde, I felt more like an astrologer than an astronomer.  I gathered my tainted image set and returned to camp.

I did briefly glance at the images acquired with the Canon. At first glance, they looked underexposed as well.  Thus, they were quickly forgotten.

Horsehead Nebula - Single Five-Minute Exposure - Pro Optic 90mm F/5.6 Lens - Canon Rebel XS (Modified)

With a storm front quickly approaching, we cancelled the rest of our trip. I bid my friend farewell, and returned to Maryland, crestfallen.

Sometime later, while struggling with Pixinsight to wring some usable images out of my data, I set my primary image set aside and looked at the images from the Canon. I pulled a single image of The Horsehead up and minimally processed it. I sat stunned as the Horsehead Nebula in all its difficult-to-image glory appeared in my screen.  

Horsehead Nebula - Histogram Stretched with Photoshop.

Yes, the image was imperfect. The less-than-perfect optics of the 90mm Pro Optic bloat stars along the edge of view. Moreover, whoever “modified” the camera, removing its infrared filter, damaged many pixels on the sensor. These show up as dark spots on the image and can be removed with flat fields.

Believing the images to be underexposed, I never bothered to gather flats or darks. Therefore, I immediately attached the camera to the 90mm Pro Optic and used a blank wall to get my flats.

Darks were going to be more difficult to acquire. They should be taken at the same temperature and exposure as the original images. How was I going to know the temperature of that humid swamp air weeks ago?  Again, serendipity stepped in to save the image. Remembering that the Zwo camera often turned its cooler off throughout then night, I need only look at the metadata from those noisy uncooled images. It was not difficult to get the sensor temperature from Zwo images taken nearly at the same time as the Canon images.

The first night was cold. Most of the uncooled images were taken at 5-7°C. I set the temperature of our refrigerator up to 6°C and placed the camera inside allowing it to take 10 five-minute exposures. The second night was warmer. Coincidentally, our garage’s temperature was the same 15°C as the swamp are on the night I took the images. The camera went from the fridge to the garage to get the second set of dark images.

With a little cropping and processing, I got the image of The Horsehead.

Here is the same data processed to bring more detail out in the nebula.

The images of The Cone Nebula were not as impressive. The nebulosity was barely visible at the edge of the field of view.

 However, with a little processing and a lot of cropping, I got a cute little image of The Christmas Tree.

The "Christmas Tree"

Images of The Rosette Nebula were not very impressive either. However, you can see its thick ring on the bottom left of the image.

Rosette Nebula - Single Five-Minute Exposure

With a little processing, The Rosette's famous ring structure becomes apparent.

Lastly, The Great Nebula in Orion shone brilliantly, I could see success on the unprocessed images. 

Orion Nebula - Single Image - Unprocessed

After stacking with Deep Sky Stacker.

Orion Nebula - Stack of 12 Five-Minute Exposures

After Working in Photoshop with the color.

When I look at these images, I cannot believe they were taken with an small telescope that I purchased to photograph the 1994 Annular Eclipse. The camera’s primary use is infrared photography.  The total cost of the setup (not including the mount) was $300.00.

Why did imaging with the new camera fail? The short answer is I was using software developed for planetary imaging to expose deep sky images. Of course not all of the images through the main scope were unusable. Those images will appear in some future blog posting.

Obviously, one doesn’t need budget-breaking equipment to obtain great astrophotographs. All that is required is good motor drive and a little serendipity.

Keep Looking Up to Clear Skies.

Ken

Cosmic Ray Strikes are Real!

Single image of M57 with Unusual Object at 5:00 Position

Earlier this year, I set up my scope for planetary imaging. Sadly, the only planet in our winter skies was faint Uranus.  Undaunted, I slewed the scope to a bright “planetary” nebula. Recently, I revisited this imaging set to find a surprise.

2018 promises to be a banner year for those of us who love to observe The Solar System. Soon, a planet parade will begin as Jupiter, Mars and Saturn appear in the east while Venus pushes herself away from solar glare in the west. Wishing to hone my planetary imaging skills, I set up my scope and ZWO ASI224MC planetary camera on a clear albeit cold evening. The icy weather and lackluster skies had kept me indoors throughout the winter. Over my shoulder, I felt Orion mocking me as I fumbled in the icy semi-darkness to get my observing session started.

As I slewed the scope to Uranus, the sole planet above the horizon, I found it obscured by my house. My scope weighs 300lbs. There was no way that I was going to move this massive behemoth on such a cold night just to image Uranus' tiny featureless disk. Looking up, I realized that M57, The Ring Nebula, stood high in the western sky.  If the planets refused to cooperate, perhaps a bright planetary nebula would be a suitable alternative.

I used the famous “Double-Double Star” (Epsilon Lyra) to tweak my focus. As these four stars danced around the field, I realized the inferiority of the night’s seeing. With the Jet Stream and its 140 mile-per-hour winds locked above Maryland throughout the winter, turbulence has destroyed our seeing. This night was no exception, and I quickly lost my enthusiasm for imaging.

Nevertheless, I dutifully centered The Ring Nebula on the chip and snapped 25 15-second images of the famous planetary nebula. The muted spectrum of color of The Ring looked like a rainbow reflected in a choppy swimming pool. Disappointed, I packed up my telescope's freezing metallic surfaces and forgot about the images. Why does the weather always seem colder when breaking down your equipment?

 

Weeks later, while organizing my images, I chanced upon the M57 data set. Upon closer inspections, the images seemed decent enough to process. Now, I would never send these images to Sky and Telescope for publishing. However, I hoped something could be salvageable. I might even get a column for the newly-born blog.

While manually inspecting each image, I noticed a surprising linear feature on the 24^th image of the set. All astrophotogrphers are accustom to the bright lines of artificial satellites bisecting our best images. Consequently, I assumed some wayward piece of space junk invaded my photography session, marked the image as unusable and moved on to the next image.

M57 - Single 15 sec. Exposure - Meade LX-850

Surprisingly, the next image in the set did not contain the trail of the satellite. I shuttered these images simultaneously with no time between successive images. The slow-moving satellite should be apparent on the next frame, A quick estimate placed the length of the track as eight arcsecs and approximately 10^th magnitude. Our moon travels through the sky at .5 arcsecs per second, so this object moved through the sky at approximately the same speed as the moon and must be approximately the same distance. Moreover, geostationary satellites at 1/10^th the distance of the moon rarely achieve 10^th magnitude. Therefore, this object must be huge – like alien space station huge.

M57 - Single 15 sec. Exposure - Meade LX-850

Perhaps I should have contacted Fox News to tell them that I had just discovered a giant alien mothership in an inclined orbit a quarter of a million miles away from the earth. I am sure they would be interested. After all, I had photographic proof.

Instead, I looked for alternative answers.

Cosmic rays are highly energetic particles originating from high energy events mostly outside of the solar system. They wreak havoc on spacecraft by literally changing the contents of computer memory or marring imaging. When they collide with the earth’s atmosphere, they cause a cascade of secondary charged particles that rain down upon the surface.

Cosmic Ray Strikes observed from the surface of Mars by The Opportunity Rover. The parallel lines are star trails while other linear features are cosmic ray strikes. - Credit NASA/JPL.

The most probably cause of my rogue satellite trail is a cosmic ray. That night, a cosmic ray entered our atmosphere. Its fast speed and high energy knocked electrons off the atoms in several pixels of my detector as it skipped across my CCD. The software assumed that everyday photons were affecting the electrons in the CCD and dutifully reported a bright object in that part of the sky.

Ironically, I began the evening in hopes of photographing a nearby planet. Having acquiesced to imaging a dying star system 2,000 light years away, I ended up capturing what possibly is a piece of galaxy that existed long ago and very far away.

By the way, here is the processed result of the imaging session:

Keep Looking up to Clear Skies.

Looking for one Satellite - Finding Many

One of the great things about astrophotography is the ability to revisit old datasets. As we acquire new skills and new processing software, we sometimes discover thing in images we discarded months or even years ago. Not a fan of imaging in sub-zero (Celsius) temperatures, I have used the past few weeks to look for interesting discoveries in last year’s images. Astrophotography is, in many ways, the gift that keeps on giving.

Nearly a year ago, Jupiter’s faint inner moon, Thebe was going to pass its greatest elongation from Jupiter between its brighter moons Europa and Callisto. Moreover, Jupiter ‘s impending opposition promised to brighten Thebe to maximum detectability. Always a fan of a Solar System challenge, I planned accordingly.

As on many early spring evenings, the wind blew furiously on the night of March 29. Undaunted, I set up in my driveway and began imaging Jupiter. My plan was to capture 30 subs in each of four different exposures later stacking them to hopefully bring out the faint moonlet from the glare of Jupiter.

Almost immediately, a streak of light crossing the computer screen caught my attention. Clearly, an Earth-orbiting satellite strayed into the telescope’s field of view. I noted the curiosity and begin my imaging sequence.

As I images, Jupiter and its moons wiggled all over the screen.  Not only was the night windy, the seeing could not have been worse. 

Soon, another satellite crossed the field of view. Happily, I captured this apparition as I was actively imaging at the time. 

During my imaging routine, seven satellites crossed the field. I captured two of them. Each crossed at the same speed with the same angle. While the cluster of artificial satellites and space debris occupy random orbits and inclinations, these seven satellites seem to follow the same routine, What could they be?

Jupiter’s declination at the time of this observation was -06°01'30".  Not surprisingly, the belt of geostationary satellites appears at approximately -6° from our location 39.5° above the equator. Serendipitously, I happened to image Jupiter during the two hours it crossed this belt. Things never work out that well for me.

Recently, I used Photoshop to create a little animated .GIF of the sequence. I was forced to overexpose Jupiter in order to make the much fainter artificial satellites more visible.

If you want to try to image geostationary satellites, Sky and Telescope published a great article detailing “How to See and Photograph Geosynchronous Satellites."

If you wish to duplicate my observations, Jupiter should re-cross the band on March  14, 2022.

Keep Looking Up to Clear Skies.

Ken