New image- Supernova Remnant

The Veil Nebula is a cloud of heated and ionized gas and dust in the constellation Cygnus.

It constitutes the visible portions of the Cygnus Loop, a supernova remnant, many portions of which have acquired their own individual names and catalogue identifiers. The source supernova was a star 20 times more massive than the Sun which exploded between 10,000 and 20,000 years ago.

Supernovae can expel several solar masses of material at speeds up to several percent of the speed of light. This drives an expanding shock wave into the surrounding interstellar medium, sweeping up an expanding shell of gas and dust observed as a supernova remnant. Supernovae are a major source of elements in the interstellar medium from oxygen to rubidium.

At the time of the explosion, the supernova would have appeared brighter than Venus in the sky, and visible in the daytime! The remnants have since expanded to cover an area of the sky roughly 3 degrees in diameter (about 6 times the diameter, and 36 times the area, of the full Moon).

The area of the nebula pictured here, also known as NGC 6960, is the “western” portion. At the top of the image is the filamentary segment often called the “Witch’s Broom”.
The image records narrowband signal from the 3 ionized gases: hydrogen alpha (red), hydrogen beta (blue), doubly ionized oxygen (teal).

Capture info:
Location: SkyPi Remote Observatory, Pie Town NM US
Telescope: Orion Optics UK AG14 (F3.8)
Mount: 10 Micron GM3000
Camera: SBIG STXL 16200
Data: H-alpha, H-beta, OIII: 6.5, 6, 7 hours respectively
Processing: Pixinsight

The entire Cygnus Loop imaged by the orbiting space telescope Galaxy Evolution Explorer or Galex which images the universe in ultraviolet wavelengths. The Eastern and Western Veil are the main portions which can be easily seen in the visible portion of the spectrum. (Courtesy Wikipedia).

The 3 “narrow band” filters used in the image were H alpha, H beta and Oxygen III or doubly ionized oxygen. These filters only allow a 5 nanometer segment of light to pass. Hydrogen alpha emits light in the red, oxygen in the green-blue and hydrogen beta in the blue. This accounts for the colors in the image.

Where is it? The Cygnus loop is in the region circled on the lower left. The constellation Cygnus (the swan) is easily recognized and is also known as the Northern Cross. It appears directly overhead during the Summer in the Northern Hemisphere. Right now you can see it there around 3am 🙂

Thanks for reading!

DrDave

Observatory News

Sunset from SkyPi Remote Observatory, Pie Town, NM

The Great Eclipse of 2024 is now over and it is time to return to Deep Space! We traveled back to the remote observatory in Pie Town NM to install a new camera system in Gamma Complex.

It’s a 4 hour journey into the most remote regions of the Southwest US. It has been about 6 months since I had to make any “service trips” up there.

The VLA’s radio dishes stand at attention waiting for their next assignment!

Our travels take us across the San Agustin Plains, an area covering about 55 miles in width. The basin, created by a prehistoric lake, is bounded on all sides by various mountain ranges. One of driest remote places in the continental US, what else would one do out here except study the distant universe? The plains are home to the VLA (very large array), part of the National Radio Astronomy Observatory. Twenty -eight radio dishes each 25 meters in diameter make up the Y-shaped array. Arid climate is absolutely essential as water molecules will cause significant aberrations in radio signal.

SkyPi Remote Observatory entrance with the mathematical “Pi” logo and surrounding pinyon trees.

Another 60 miles west and we have arrived at our destination, SkyPi Remote Observatory, founded in 2012. The observatory complex is home currently to 5 roll-offs containing 8 telescope piers. They are named Alpha, Beta, Gamma, Delta and Omega (the owner has an aerospace background!). My equipment resides in Delta and Gamma. A 4-pier roll-off expansion is planned for the coming year.

Two of the 5 roll-offs are shown here (Alpha and Beta). These roofs roll off to the west. You can barely see the tracks to the left.

Eastern view from the observatory complex. Looks like the scene of an old western movie perhaps!

The walk or drive up to Gamma and Delta where my equipment resides. The pinyon or piñon pine tree grows in southwestern North America, especially in New Mexico, Colorado, Arizona, and Utah. These trees have a very ethereal vibe to them, perfectly suited for an observatory site!

Outside of the observatories, it’s just you, the Pinyon trees and the Universe!

And now back to business here, the purpose of this trip is to replace our “old” CCD camera with a new CMOS version.

We’re replacing this CCD camera (about 6 pounds)

With this one (< 1 pound)!

We have discussed the whole camera technology changing over from CCD to CMOS in previous posts, but just to review, CCD (charge coupled device) and CMOS (complementary metal oxide semiconductor) image sensors are two different technologies for capturing images digitally. Both types of imagers convert light into electric charge and process it into electronic signals. CCDs and CMOS imagers were both invented in the late 1960s and 1970s. CCD became dominant initially, primarily because they gave far superior images with the fabrication technology available at the time.

However, with the promise of lower power consumption and higher integration for smaller components, CMOS designers focused efforts on imagers for mobile phones, the highest volume image sensor application in the world. This is what changed everything as the CCD market was quite narrow and limited to astroimaging and other science applications while CMOS technology could be applied to a huge global consumer market including smartphones, webcams, video surveillance etc. The CCD phase-out was thus inevitable.

An enormous amount of investment was made to develop and fine tune CMOS imagers and the fabrication processes that manufacture them. As a result of this investment, we witnessed great improvements in image quality, even as pixel sizes shrank and at this time, based on almost every performance parameter imaginable, CMOS imagers now outperform CCDs. As I commented before, this is one instance where cheaper IS actually better! Contemporary CMOS astroimaging cameras typically cost at least 50% less than their CCD predecessors.

The mount’s torque motors go through a series of movements to measure the telescope’s balance i.e “front heavy” or “back heavy” so any necessary adjustments can be made. This enables a very precise correction to within 0.1 %

Replacing a camera system involves several steps including rebalancing the optical system, especially in this case as I had to remove a 40 pound counterweight after the install! Then the mount has to “relearn” how to point to objects in the sky after the weight and balance has changed. Finally a new “profile” has to be created in the control software to include the new camera and guider specs and the new image scale as the new sensors have different dimensions and pixel sizes.

First light image with new camera system! This is a 5 minute raw uncalibrated image with a waxing gibbous moon.

Annotated image. NGC 4725 is an intermediate barred spiral galaxy with a prominent ring structure, located in the northern constellation of Coma Berenices. A likely companion galaxy to the left is the irregular NGC 4747, also known as ARP 159. A tidal plume is seen emanating from the left edge. More on this group at the completion of the project!

The camera installation project took 3 days and 3 nights to complete but our “first light” image is very encouraging!

Multiple pier roll-off at the new HCRO observatory

Finally I visited a new observatory complex under construction just “over the hill” from SkyPi. “Howling Coyote Remote Observatories” is yet another telescope hosting facility with identical conditions to SkyPi but on a much bigger scale. Currently there are around 7 telescopes in 2 roll-offs but plans are in the works for around 50 or more piers!

Piers arranged inside the observatory at HCRO

A Planewave Delta Rho telescope at HCRO

And that sums up my recent service trip to SkyPi Remote Observatory !

Thanks for reading!
DrDave

Eclipse 2024 post mortem!

This was probably the best image from the day! Unexpected for sure but I did capture the prominences at C2.

We were actually pretty fortunate with the weather as complete overcast skies were initially forecast but we were on the edge of the cloud bands. The sun was in and out of the clouds and we got glimpses of the partial phases up through about mid-totality. Actually the clouds added a little drama to the whole thing! It was of course fantastic to be there and see what we were able to see. We could not see associated phenomena such as shadow bands or the approaching Moon’s shadow. Probably the most remarkable thing was that during totality, with the clouds present, it was pitch dark! I could not see my equipment at all, so it took me me about 30 seconds to find the usb-c port on my laptop in order to change the drive mode from high speed back to single shot. I think because of that I was not able to get more images during totality. And because of the clouds there were only about 2 minutes where we could see it at all.

Here are the other images from the day:

This was the only image obtained at the start of totality, probably within the first minute.

There could not have been a more perfect observing site! Maybe 10 of us were present in this field by the river. I think there were about 30 people total at the resort. Many set up right next to their cabins.

Partial eclipse, about 30 minutes or so before C2.

Just after the very beginning. You can see 2 sunspot groups, one close to the center and one near the bottom.

This was about 25 seconds or so before C2. I did have the high speed mode active but I had to go totally off script and basically guess on exposure time. These were all ISO 200, F6.3, 1/60 sec. Normally this part of the eclipse you need to have an exposure of 1/4000. I did see somewhere in the case of clouds that exposure was decreased to 1/30-1/60.

Baily’s beads through the clouds! Overall I had the right idea and my planning was geared toward this phase of the eclipse, so considering the adverse conditions we had some success!

Final glimpse of sunlight before totality begins! All in all, we did get to see it despite the weather and as I was saying the cloud coverage added a totally unexpected drama to the experience!

Next stop will be Spain in 2026!

Thanks for reading!

DrDave

Eclipse Day 0!

And so we are finally here at the eclipse observing site! Unfortunately it looks like the event will be completely clouded out 😦 In fact, most of the eclipse path will be adversely affected by inclement weather.

Probably the only guaranteed viewing spot is way up in the Northeast US and Canada! The worst case scenario. But the positive spin on this is that there is absolutely no way we were going to drive across country to chase it.

The other plus is that we did choose a nice vacation spot which is the “Hill Country” in Southeast Texas. We are in a town called Ingram which is in Kerrville County. Scenic rolling hills abound with the Guadalupe River running through it.

We are staying at a riverfront cabin. In this pano image the cabins are on the right and the river is actually about 30 yards from the fence on your left.

And as I mentioned in the last post there is fishing here! Trout is the most abundant, but there is also bass, which I think the fish above is, and perch.

Now stranger things have happened. The Kerrville clear sky clock above shows the time just before the start of the eclipse as clear (blue squares) but then at totality the cloud coverage increases to around 60-70% (white circle). If that shifts slightly we could be in luck! But as of 5am local time it’s not looking particularly encouraging.

In the event of overcast skies we might consider watching the umbral shadow approaching. Or we can always just watch the NASA webcast!

Thanks for reading!

DrDave

Eclipse Day 10

And so we continue with eclipse preparations, now about 10 days to go! Last time we came up with the strategy we will use for the eclipse, tested switching to high speed drive mode and used the intervalometer. We retested focus at 15x and checked a sample of images from the high speed sequence to make sure they were captured and were in focus. We tweaked tracking by figuring out the correction needed between the magnetic pole from the smart phone app and true north since most likely we’re polar aligning during the day.

Today we ran through a timed simulation, beginning with setting up high speed drive mode using the laptop, deploying the shutter for 25 seconds, then switching to single shot mode, setting exposure to 1/2000 and going through a manual sequence of turning the exposure wheel 2 clicks down x 20 times. These are the resulting exposures which would occur during totality:

1/2000, 1/1250, 1/800, 1/500, 1/320, 1/200, 1/125, 1/80, 1/50, 1/30, 1/20, 1/13, 1/8, 1/5, 1/3, 1/2, .8, 1, 2+. 3+

Exposures > 1 sec might capture the Moon’s surface detail.

Picture of set up including Celestron AVX mount, Canon R5 with 500mm telephoto, cardboard box with laptop inside shielded from Sun (kind of- there still is a fare amount of glare in there). Lithium battery is used for power for laptop and mount

After the single shot sequence above, I had to go back to the laptop and change the drive mode back to high speed and reset exposure back 1/4000. Each time you’re done with settings in the utility, you have to be sure to close out of the ultility software and disconnect the camera-laptop usb otherwise the intervalometer will not deploy a high speed shutter burst.

I did 2 runs. The first one, again from high speed shutter at C2 to high speed mode at C3, with the single exposures in between took 4′ 25″. The second one I was able to decrease it to 4′ 8″. The duration of totality is 4′ 25″. This is basically what will save us! This is a fairly long eclipse. So I think we will be good especially with a few more practice runs. The eclipse practice run in the Solar Eclipse Timer app (see last post) uses the 2 minute eclipse from 2017. With my approach I probably would not have been able to get the exiting images at C3, but we will run through that just to hear the announcements that the app plays to you and we can still get a feel for going through the steps as long as we can.

Basically from here on out we will continue to practice, perhaps shaving off a few more seconds. When we arrive at the observing site we can load in the exact longitude and lattitude into the app so it will produce the contact times and be able to run properly.

And finally the weather update….bad 😦 10 day forecasts can be 50/50 though, so we will see.

Thanks for reading!

DrDave

New image- Edge on NGC 1055

NGC 1055 is an edge-on spiral galaxy located in the constellation Cetus . “Edge on” meaning the plane of the galaxy lies along our line of sight as opposed to “face-on”. Imagine looking at the edge of a dinner plate. This would be the edge on view. When you can see the whole round plate in front of you, as well as what’s for dinner :), this is the face on view.

This image is featured on March 15 APOD https://apod.nasa.gov/apod/ap240315.html

The galaxy has a prominent nuclear bulge crossed by a wide knotty dark lane of dust and gas. The spiral arm structure appears to be elevated above the galaxy’s plane and obscures the upper half of the bulge. Discovered on December 19, 1783 by William Herschel.

A rough distance estimate for NGC 1055 is 52 million light-years, with a diameter of about 115,800 light-years, slightly larger than our own Milky Way (about 106,000 light year diameter). NGC 1055 has extremely active star formation and is a bright infrared and radio source.
It is in a binary galaxy system with neighboring M77 (previously imaged- see below) and there are a few million light years between them. Unfortunately I could not quite get both galaxies in the same image field!

Capture info:
Location: SkyPi Remote Observatory, Pie Town, NM US
Telescope: Officina Stellare RiDK 400mm
Camera: SBIG STX 16803
Mount: Paramount MEII
Data: LRGB 8,7,7,7 hours respectively
Processing: Pixinsight

M77 above , the binary sibling of NGC 1055, is a barred spiral galaxy 47 million light years away in the constellation Cetus (The Sea Monster in Greek mythology but typically whale in modern times). Fitting for this galaxy because it belongs to the Seyfert class of galaxies, one of the two largest groups of galaxies that contain active galactic nuclei which are characterized by the presence of a supermassive black hole at the center. These are the most luminous sources of electromagnetic radiation in the universe and while most of the radiation is in the form of high energy xrays and ultraviolet, 5% of Seyferts, including this one, are also strong in radio emissions. This has been studied extensively by the VLA (Very Large Array), an array of radio telescopes right here in New Mexico and only about 45 minutes from my rigs in Pie Town! The strong radio source is designated “Cetus A”.

NGC 1055 is low in the Southwest at sunset here in the northern hemisphere (blue square). It is in the constellation Cetus, near the head of the whale. It is quite dim, near magnitude 11, so a large telescope is required to even recognize a faint smudge in the field of view!

Thanks for reading!

DrDave

New image- M3

M3, located in the constellation Canes Venatici, is a stellar marvel approximately 33,900 light-years from Earth. This globular cluster boasts a dense concentration of stars, with estimates ranging from 500,000 to over a million stars packed within a region spanning about 180 light-years.

At an estimated age of around 11.4 billion years, M3 predates many other celestial objects in its vicinity, including our own Sun. Its stellar population contains a diverse array of stars, from ancient red giants to younger main-sequence stars. Studying the chemical composition of these stars provides astronomers with valuable insights into the early stages of galaxy formation and the evolution of stellar populations over cosmic time.

M3’s position in the sky allows for detailed observations and analysis, making it a key target for astronomers studying stellar dynamics, stellar evolution, and the structure of globular clusters. By measuring the brightness and colors of individual stars within M3, scientists can infer properties such as stellar ages, masses, and chemical compositions, shedding light on the processes that govern the formation and evolution of stars within dense stellar environments. As researchers continue to unravel the secrets of M3, this globular cluster remains a beacon of discovery, offering a window into the distant past of our galaxy and the broader universe beyond.

Not exactly a “new” image, but kind of reposted from my last entry. This was really a “test” first light image with a new portable set up shown below. This image was selected for today’s “Amateur Astronomy Picture of the Day”. https://www.aapod2.com/blog/plre1sthlc2gusplzd1rw26htoxmk5

Here I spend all this time and expense with these large remote rigs and it’s this simple set up producing remarkable images! What is most amazing to me is that this image was taken with a one shot color camera (no additional color filters. Basically like a regular digital camera except you can cool the camera down), in a fairly light polluted sky! (Bortle 5-6) The new CMOS (Complementary Metal Oxide Semiconductor) camera technology is leaving the traditional CCD (silicon based “Charged Couple Device”) in the proverbial dust! Believe it or not in this case cheaper is actually better. See this page for a more detailed explanation of CMOS vs CCD.

Equipment set up for the above image. Basically 4″ refracting telescope, color camera, mini PC attached and lithium battery on the lower right for computer and control hub power. The bag in the middle is 15 pounds weight to stabilize the tripod.

So take home message is current technology is making amazing things possible with modest investment!

Thanks for reading!

DrDave

Macro to micro

Outside of a couple of visits to eclipses and the Venus transit back in 2005 I think it was, I have very little experience with dedicated portable imaging equipment. I have been very spoiled having permanently installed imaging platforms I can run remotely and have been doing that for years. However now that I am fully retired, my wife and I purchased a comparatively small RV that among other planned destinations include a number of the darkest spots in the US. They all happen to be right here in the desert Southwest!

Of course I plan to take full advantage by employing a number of portable setups. The one pictured above is probably the most compact and lightweight for telescope gear. It is probably the latest technology for “grab and go” full imaging rigs.

Let’s examine the components!

Setting up an efficient portable platform is in some ways more challenging than a permanent rig. If you’re traveling to a dark site it will be quite remote which means there are no services. You will need some kind of power source. In this situation less is a lot more. Your camera, focuser, mount and computer all require power, not a ton but they will need it from somewhere.

At least one component to run properly requires AC power via an adaptor. In my case there are 2. The Pegasus “power box” (labeled ‘Peg’ in above image) manufactured by Pegasus Astro is an excellent portable 12volt power source and hub for usb devices. The Intel nuc 11 is a mini PC which weighs about 1 pound. Several more contemporary mini-PCs are able to run off of 12 volts. Unfortunately this is not one of them. The nuc 11 requires 19 volts which means I have to use the AC adaptor.

Ok so how do you use the computer if you don’t have a monitor connected to it? You have to connect into it via a wireless network. If you are at home and you have wireless internet this is fairly easy to do. If you are going to a dark site you will need to have some sort of mobile wireless service. There are several options. If you are camping for example you can remote into the telescope PC with another laptop, tablet or even smart phone.

For AC power there are a number of portable power options. There are now portable lithium batteries than can conveniently power AC equipment. The one I use is made by Jackery

The camera (labeled ‘C’) is a QHY268C color CMOS camera. As I am discovering the new CMOS sensors are proving to be much more sensitive than the traditional CCD sensors. A “one shot color” camera is well suited for portable rigs as it obviates the need for additional filter wheels which can add significant weight, and weight is a major concern for ultra-portable set-ups.

And now the most important component to discuss is the mount. This is labeled “RST” above, This is the Rainbow Astro RST 135E “weightless” mount meaning it is designed to operate without counterweights. Instead of worm gears, a new type of reducer called strain wave gear (harmonic drive) is used. Almost no backlash and no maintenance is required. As it is widely used in industrial robots, it is very durable. Many versions of this type of mount are available now. The RST was one of the first. However, there is a trade-off of course! The maximum weight capacity is 30 pounds, so you have to carefully weigh every ounce!

The mount is powered by a small lithium battery that can be stowed in the bag shown at the top. It supplies 15 volts of power.

The telescope is a Takahashi FSQ106N (4″ refractor). This is the original version of the popular 106 model that was introduced around 2004. Thankfully it’s a few pounds lighter than contemporary 106’s.

Other labeled components are ‘O’ which is the “off axis guider”. This device is basically a tiny prism that deflects a small portion of the incoming light to a guide camera “G”. And finally ‘D’ is a filter drawer that can accomodate a filter for narrow band imaging.

The whole package weighs approximately 22 pounds!

This is a very important equipment detail which is the “polemaster” camera shown pointing toward us, actually pointing at the celestial pole which for my residence is about 32 degrees north. As this is a portable system, every time you set up you do have to align your mount to the celestial north so it can track properly. The Polemaster uses a super-sensitive wide-field imaging camera that’s mounted on the RA axis of your mount. The RST conveniently has a Polemaster adaptor built into it. The camera in the PoleMaster images the region around Polaris (the North star) in real time, detecting Polaris itself as well as the fainter nearby stars. Using the positions of these stars, PoleMaster determines the position of the north celestial pole and compares it to the mount’s RA axis of rotation. Polar alignment is now a simple matter of moving the two centers of rotation so they overlap. This process takes about a half hour.

I have found that the tripod alignment can remain stable over several nights provided wind is no more than about 15 mph.

A hook underneath the mount allows for placing additional weight to stabilize the carbon fiber tripod. The tripod itself has a 50+ pound capacity. I have placed 15 pounds of weight in this bag. The mount battery can be stored in there as well.

Ok that’s all fine, but now what about the performance of all this?

Above is a first light image of the globular cluster M3. I thought it was a good test because it’s all stars! A star cluster is very unforgiving. If you have any issues with tracking or guiding it will be immediately obvious. I am very pleased with the performance of this rig. As you can see the star images are very good. I am able to guide easily up to 10 minutes or more with no significant errors. The guide error seems to be consistently around 0.5 arc sec. The above image consisted of 41 x 5 minute exposures.

A few notes on M3 itself:

The globular cluster M3 was the first object in the Messier catalog to be discovered by Charles Messier himself. Messier spotted the cluster in 1764, mistaking it for a nebula without any stars. This misunderstanding of M3’s nature was corrected in 1784 when William Herschel was able to resolve the cluster’s individual stars. Today it is known to contain over 500,000 stars.

M3 is notable for containing more variable stars than any other known cluster. The brightness of a variable star fluctuates with time. M3 contains at least 274 variable stars.
Interestingly, M3 is actually larger in size than the well known Great Cluster M13 in Hercules. M3 is estimated to be 180 light years in diameter vs M13 about 120. However M3 is 10,000 light years more distant than M13. Both clusters are very old, about 11+ billion years.

And finally is there anything else I learned about the “ultraportable” platform. Of course! I would say these are the most important things:

1. There are mini pcs which can run off 12 volt power. In fact I am using one in one of my remote rigs. This would enable you to lose at least one of the adaptor power bricks and thereby lighten things up.
2. It’s important to respect the weight limits of these. If you load things up to even slightly less than the maximum weight, performance will be affected adversely. Be very conservative and make sure you’re not closer than even 4-5 pounds to the max weight.
3. Polar alignment is critically important. The better polar alignment you have, the better your guiding and tracking will be.
4. I did struggle for a few months with this before getting anything consistently acceptable. The breakthrough occurred when I changed from using a separate guide scope to what is shown here, namely the OAG or off axis guider. There was no way to solidly mount the guide scope. I tried several methods none of which worked, It’s also very important to make sure if you are using a separate guide scope that it is a proper match for your telescope. The formula to figure minimum guider focal length is (again for all amateur astronomers out there!): 0.2 x Guide camera pixel size in microns x telescope focal length divided by imaging camera pixel size.
5. I was recommended the carbon fiber tripod as a good match for the RST. It’s max weight capacity is over 50 pounds but it’s not the most stable platform out there. I found hanging off that additional 15 pounds makes a huge difference.
6. The other item I struggled with was figuring out how to get this telescope to point to objects in the sky accurately. At first I based my approach on previous experience I had with the 10 Micron mount which at first glance has similar features in the sense that you have a handpad that has a built in alignment process using 6 stars. This star alignment process saves the results internally in the mount kind of like the 10 Micron. The problem is that for imaging, 6 stars is not nearly enough! If you go through the process manually it takes forever and then you find out it’s not accurate enough. I decided to try an alignment process external to the mount and used also something I have experience with which is T-point from the The Sky X (Software Bisque). You can model as many points as you wish. For this mount I typically do around 60 points. That solved the pointing accuracy problem!

Anyway that’s all for now! Looking forward to more images with this “ultraportable” set-up.

Thanks for reading!

DrDave

Eclipse Day 65

We continue our preparations for the total solar eclipse of April 8, just over 2 months away now! So many details to sort through! The last eclipse of 2017 was my first and I recall many people told me not to bring equipment because you want to be able to observe all the events surrounding totality with your own eyes. “Don’t waste precious time fussing with imaging rigs because you will miss the whole thing”. Well of course I did not listen and brought the whole enchilada, telescope with heavy duty mount etc etc! Despite all that I got to witness everything completely stress free while I ran my telescope rig fully automated. You can read about that in the various posts on this site just by searching under “eclipse”. Preparation obviously is the key and can’t be stressed enough.

There are so many approaches to this and you can’t do it all so it’s best to decide what your goal is going to be.

Here is a list of the general imaging strategies:

1. Framing in close with long telephoto lens or telescope
2. Wide angle shots or panoramas
3. Time lapses which show the passage of the lunar shadow and changing sky colors
4. Rapid-fire stills or a movie capture the iconic“diamond rings” as the Sun disappears, then reappears from behind the Moon.
5. Composites blend all the stages of the eclipse onto one frame.
6. Movies

For myself I am still planning to focus on the events surrounding totality kind of like I did last time so we’re looking at number 1 in the above list. However this time I am also adding number 4 since last eclipse I kind of captured one frame of diamond ring only and it wasn’t that good. If I am really ambitious, maybe also number 5! 🙂

Now the “events surrounding totality” are those that occur from “second contact” or C2 through “third contact” or C3. At C2 the total eclipse begins. The Moon covers the last bit of the Sun’s bright
photosphere, as the diamond ring effect is ending and complete totality begins. At C3 the total eclipse ends. Another diamond ring announces the end of the short 4 minutes of totality. Remember that from C2 to C3 you have to REMOVE filters for your photographs otherwise you won’t record anything! During the partial phases, technically C1 and C4, you have to use your filter if your optics are exposed during that time.

What are the phenomena we expect to image during totality?

Baily’s Beads. The Baily’s Beads effect is seen as the Moon makes its final move over the Sun. This effect occurs when gaps in the Moon’s rugged terrain allows sunlight to pass through in some places just before the total phase of the eclipse. The effect is named after Francis Baily, who explained the phenomenon in 1836. (image courtesy NASA)

Diamond Ring. The diamond-ring effect occurs at the beginning and end of totality. It’s the stage just before Baily’s Beads during second contact or just after during 3rd contact. As the last bits of sunlight pass through the valleys on the moon’s limb, and the faint corona around the Sun is just becoming visible, it looks like a ring with a “glittering diamond” on it. (image courtesy NASA)

Corona. The solar corona is of course the “holy grail” of eclipse photography! It is also the most compelling astronomical sight a human can witness (in my humble opinion!). It can only be seen during a total solar eclipse, unless of course you have special equipment such as that used by NASA or other institutions around the world. The corona is the outermost layer of the Sun’s atmosphere and extends millions of kilometers into space. It’s structure is quite variable and will be different for each eclipse you observe! (image courtesy NASA)

Ok so what did I learn from my last experience I can take into preparations this time around?

1. Take a close look at the header image at the top of this post, the one with the countdown superimposed on it. This was taken by me during the total eclipse of August 17, 2017 in Casper Wyoming. What do you see there? Yes I thought it was a pretty decent capture for a newbie eclipse photographer, except for one thing. The corona is cut off! I did not realize how big an area is covered by the sun’s corona. It can be easily a few solar diameters wide! The equipment I used was a 4 inch refracting telescope and standard dslr camera. The focal length was 800mm which is quite long and field of view was not that big and clearly not big enough to capture the whole corona.

   So this time I will ditch the telescope and stick with a telephoto lens and full frame camera which should yield a field of view plenty big enough to get the whole thing!

The Sun first appears at the end of totality creating the “Diamond Ring” effect!

2. This was also an image I took back in 2017, but it was the only frame I got showing the diamond ring and I did not capture any of the Baily’s beads. Baily’s is a major challenge as the effect lasts for literally seconds, maybe 3-5! I used a technique called “tethered automation” meaning the camera was connected to my laptop and the automation program controlled the camera via the usb connection. I believe this limited the number of frames that could be taken during the very short time between the start of 2nd contact and full totality or end of totality and beginning of 3rd contact. This was probably only about 15-20 seconds or so. I believe that my full frame camera with blue tooth shutter will enable much higher frequency of frame capture. We will see in the coming weeks!

Just at the end of second contact, solar prominences can be seen!

3. The above image is the best one I took in 2017. After Baily’s beads, 2nd contact, moments before full totality I was able to capture solar prominences! A solar prominence (also known as a filament when viewed against the solar disk) is a large, bright feature extending outward from the Sun’s surface. Prominences are anchored to the Sun’s surface in the photosphere, and extend outwards into the Sun’s corona. Looking back at my experiences in 2017, I would say the ONLY advantage of using a telescope would be if you wanted to focus on this particular feature during the eclipse. Telephoto images can pick this up occasionally but not nearly as detailed.

So where do we go from here? Of course testing, testing and more testing including equipment, software, set up etc.

Just a couple of preliminary points before closing. The annular eclipse I observed back in October was a special case of an extended partial eclipse so for that I had to keep the camera filtered for the duration. This was a threaded filter I screwed on to the lens and just left it on. For complete totality though you will have to be able to remove the filter quickly in order to capture the events during totality. A threaded filter is not going to work!

Solar filter from Kendrick Astro Instruments. This has a built in solar finder! (top)

I recently obtained a solar filter from Kendrick Astro Instruments to fit over my telephoto lens. Kendrick is a well known Canadian company, been around for years. The filters are light weight, easily slipped on and off. They also have a built in solar finder! Genius!

Solar filter positioned over the lens. 3 nylon thumb screws stabilize it.

The image above shows the filter in place. Good news this time the eclipse occurs around 1-1:30, so the lens will be pointed upward, making it possible to leave the screws a little loose. This way the filter can be rapidly removed for go time!

And finally if you are planning for this don’t struggle looking for information in a million places online. Get this ebook written by eclipse photographer Alan Dyer. It is indispensable!

Thanks for hanging in there this time! Took a little longer than anticipated.

DrDave

New image- The Ghost

The “Ghost Nebula” (designated Sh2-136, VdB 141) is a reflection nebula located in the constellation Cepheus.

The VdB catalog was originally published in 1966 by Sidney van den Bergh and contains 159 reflection nebulae. Reflection nebulae are clouds of interstellar dust which might reflect the light of a nearby star or stars. The energy from the nearby stars is insufficient to ionize the gas of the nebula to create an emission nebula, but is enough to give sufficient scattering to make the dust visible.

The “Ghost” lies near the star cluster NGC 7023. There are several stars embedded, whose reflected light make the nebula appear a yellowish-brown color giving it the eerie “ghost-like” appearance. The surrounding region is filled with interstellar dust and gas. The Universe is a very dusty place. Cosmic dust consists of tiny particles of solid material floating around in the space between the stars. It is not the same as the dust you find in your house but more like smoke with small particles varying from collections of just a few molecules to grains of 0.1 mm in size.

Capture info for the above image:

Location: SkyPi Remote Observatory, Pie Town, NM US
Telescope: Orion Optics UK AG14 F3.8
Mount: 10 Micron GM3000
Camera: SBIG STXL 16200
Data:
LRGB 7,6,5,6 hours respectively
Processing: Pixinsight

The Ghost is located in the constallation Cepheus. Shown above, it is marked by the red square at the center of the image.

That’s all for now! Next up, we will continue our eclipse preparations.

Thanks for reading!

DrDave