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 Day 21

And so we continue our total eclipse preparations! Now about 3 weeks out, but for me a few days less because we are leaving actually on the 4th of April, visitng friends down in Texas for a couple days before heading to the observing site on the 6th.

That being the case, we are really going to have to have everything dialed in prior to April 4th which is at least my official deployment day!

Today we started getting into some serious equipment work. As some of you may recall, I discovered the Celestron AVX control board failed sometime since the last total eclipse in 2017. We had to go manual for the annular eclipse last October (see “ring of fire” post) and that worked fine for that event but for a total eclipse there are so many things happening you do not want to fuss with moving the RA axis of the mount every 20 seconds or so.

Camera mounted on Celestron AVX mount

Immediately after the October eclipse I shipped the mount back to Celestron and they successfully updated the control board! I tested the mount shown above and we are able to align perfectly fine on the sun after setting the time and location (you have to enable the sun as an object in the handpad because all of these mounts have built in sun pointing restrictions . Manufacturers don’t want anyone looking at the sun with no protection!)

I was able to confirm accurate pointing and tracking. Slewing the camera to the Sun was close enough to where the projected image of the Sun on the filter was close to the target and in the camera, the Sun was at least in the field of view! This is huge because now we can focus efforts on exposure timing etc without having to worry about the Sun leaving the field.

The projected white dot of the Sun easily falls somewhere on the metal plate, then it is a simple matter to center it inside the target with the handpad (black arrow).

I should point out that prior to turning on the mount I did a very rough daytime polar alignment just using a smartphone compass and making an altitude adjustment using the calibrated scale on the mount. Even with this crude, hardly accurate method the tracking was quite good! I plan to fine tune this at the observing site, hopefully aligning on Polaris the night or 2 before.

Centering the Sun projection on the filter yields this position of the Sun in the camera FOV. This will improve once we get better polar alignment.

Now honestly I cannot imagine possibly figuring anything out regarding focusing using the camera’s flip screen. Maybe it’s just my age but in the bright sunlight I cannot see a darn thing on that screen! So I have decided to use a laptop placed inside a cardboard box, somewhat shielded from the sunlight so I can focus the camera and center the image. In this test the box was tilted a little more toward the Sun than it will be on eclipse day.

This will be the only purpose of a laptop connection, namely focusing and centering. At the last eclipse I ran the whole thing automated with the laptop connected. This was fantastic for my first go, but as I have learned this approach cannot work for capturing the fleeting events of the beginning of second contact, (diamond ring, Baily’s beads). The program I used basically automated a bracketed exposure sequence which can work for the Corona during totality but you need too many exposures in too short a period to do what we want to do this time.

In addition to testing the mount, we needed to focus and then determine an optimal exposure for the Sun’s disc. I will explain why that is necessary later. I also wanted to see if focus was maintained over a period of time and also if the mount’s tracking would keep the Sun in the field for at least a half hour or so.

At the last eclipse I mentioned I did have trouble with the Canon Eos Utility program crashing after maybe 30 minutes or so of usage but it’s very simple to use and this time I am using it only for focus and centering so that will only take a few minutes. Once that is done I should not have to connect the camera again (hopefully!). Here you can see it’s easy to identify the shutter speed settings and then use the round black button at the top right to take the exposure.

The reason we need to determine the best exposure for the Sun’s disc is that 2-3 stops faster will be what you will need for Diamond rings etc.

For focusing use the “Live View Shoot” mode (blue arrow). Click on the ‘x6’ magnification button. If you get a “Busy” error message in the top screen (blue ‘X’) just close out of live view and reopen, then click on the x6 button again. I thought 6 times mag was totally sufficient. Things are already bouncing around like crazy so any more I think would be a bit much. Focus on a sunspot group (we have an active solar period now!), but if you don’t have that to look at focus on the Sun’s edge.

Once you have achieved focus, put a piece of tape on the focus ring. Use Gaffers tape if you can get it. It’s used in the construction field: a light weight cotton-like material that is perfect for optical gear. It will not leave any residue on your equipment and is very easy to remove and also re-usable many times.

This is 1/2000 sec ISO 200 F6.3, 500mm FL. I used 600mm at the last eclipse and figured I’d back off just a tad to enable capturing of the full corona. This image is cropped so you can see the sunspot groups better.

This is 1/2500 sec. I tested exposures from 1/200 all the way up to 1/5000. The color with this kind of filter is very white with kind of central blush in there almost greenish so it might be a little more challenging to assess the correct exposure, but 1/2000 to 2500 looks about right.

I then waited nearly a half hour and repeated a 1/2500 shot to see if focus was maintained. Looks like it is the same. It’s a challenge manually focusing a long telephoto but I think it’s just about there. We will have many chances to improve on it if that’s possible.

This is the actual full frame image scale uncropped so you can imagine that with the Sun centered there should be no problem capturing the full corona. This was the position after 30 minutes from when I had centered it so that’s still pretty good despite the very rough polar alignment!

So let’s assume 1/2000 is our disc exposure. We’re looking at probably around 1/4000 for Diamond ring etc.

Next up we need to test high speed continuous shooting with an intervalometer!

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

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

Observatory News

Gamma complex, SkyPi remote Observatory, opening for the night’s imaging session. My scope is the one moving in the foreground. This is an Orion Optics AG14 newtonian (F3.8)

Observatory news for November 2023:

Time to recollimate the AG14 newtonian! Generally the collimation is pretty stable but periodically has to be tweaked a little.

I think it has been helpful for folks to see the details of that last step in the collimation process which is the most important for imaging. There are a bzillion references out there for basic newtonian collimation which all can work. Here is a very good one for preliminary optical collimation. However more contemporary software methods for the last step can be very complex and difficult to navigate. What I have done is very straightforward and has worked for the last 20 years since the software I am using was developed.

Newtonian optical design. Arrows show light coming into the telescope from space. ‘P’ is the primary parabolic mirror, ‘S’ is the secondary flat mirror which reflects the light out of the side of the tube. The light passes through a “corrector lens” C just before it enters the camera

The first two collimation steps (1.Center secondary in the focuser 2. Collimating eyepiece to center of primary) were carried out during the initial set up stages and I just use a basic sight tube for that. The eye is an excellent judge of alignment during these stages. I do that without the corrector lens.

“Catseye” XLS sight tubes. These are adjustable to your focal length

We will focus on the last more critical step which is to align the primary to the optical axis center. To do that you must have your imaging system set up and this step is done at night at the telescope.

Rear of the telescope showing the 3 pairs of collimation screws

I set up with a laptop next to the scope and collimate on a star overhead and in front of me such that I can easily reach the collimation screws at the rear. Usually this equates to an altitude of around 70 or so.

The software I use is called CCD Inspector by CCDWare. Ok so it’s 20 years old but it still works! And you don’t have to be able to solve differential equations to use it!

Basically the principle is you’re going to use a defocused star to do the collimation. For smoothest operations you should have your focuser set up so that focus occurs near the middle of focus travel. Use a star of magnitude suitable for your focal length such that around a 2 sec exposure is sufficient. For example for focal length 1300 which is this scope, a 4-5 magnitude star works.

Open CCD inspector and in the main window make sure the “In Arcsec” box is checked

Configure your imaging system characteristics

Set your image scale and camera properties

Select “generic” as your camera control software. I am using The Sky X but I believe that this should work with any program you are using.

When you click on “generic” above you will get a pop up asking you to select a folder where the images will be saved. This is the key step. You have to configure BOTH CCD Inspector and your camera control program to save to the same folder otherwise it won’t work.

Last thing you want to do here is make sure real time> collimation> defocused star collimation viewer is selected and I would also recommend here under “images to average” that you choose one image. You’re going to take a series of single images. This allows you to see the arrow position changing or not (see below).

Now what you want to do is first find your star and make sure it’s centered. Then fully rack out the focuser. I would also recommend taking a subframe, otherwise you are likely to get multiple stars in the field. I use 1/4. Then take a 2 second image. You should see a defocused star with a diameter of at least 200 pixels. This is why it is best if the focuser is centered to begin with. If the star image is too dim you will get an error stating that and then perhaps increase exposure. If you get “star image distorted” multiple times you might need to choose a different star or it might be too small of a star image. It can take a while to find the right combo of star and exposure time.

You should see something like this above. A defocused star in your exposed image and the CCDI graphic “One Star Collimation Viewer” showing an arrow pointing in a specific direction with a collimation error read in arcsec. In this case I started with a 7.5 arc sec error, not bad but needs a little improvement. Take multiple single images of the defocused star to confirm the collimation arrow direction. You should do this each time.

Next you need to move the star image in the direction of the arrow, in this case upward, by slightly turning the collimation screw or screws. This is totally trial and error but once you find out which screws move the image which direction it goes a lot faster. Use very slight turns only. Once you have made an image shift in the right direction, you need to recenter the star and start again. In my case I have to return the focuser to the focus position, recenter the star and then defocus again. When you arrive at the defocused position take multiple single images to confirm the direction of the collimation arrow like before.

While you are doing this the collimation arrow will continue to point in roughly the same position but as your collimation improves and the arc sec values decrease you will get to a point where the arrow starts to “flip” to different areas with each exposure. This means you are done. It will depend on the seeing how much correction you can get. Less than 5 arc sec is pretty good. Less than 3 is excellent.

In very good seeing conditions you can occasionally get sub-arc-second collimation results as we did here. Note the secondary shadow will be very slightly offset. This is normal for newtonian optics.

And that’s it for precision software collimation of newtonian optics!

Next up- new image

Thanks for reading!

DrDave

New image- SN2023ijd

Well not exactly a “new image” but a fully processed version of the galaxy field surrounding supernova SN2023ijd. I presented the first images back in May when it was first discovered. You can read about that here

This shows the actual location. As we discussed in the previous post on this, a lot of excitement surrounded the discovery on May 19 of Supernova 2023ixf in the “Pinwheel Galaxy” M101. That event was much brighter and could be seen in small telescopes.
However only about 5 days before SN 2023ixf blew up, another star went through it’s last moments of life and subsequently blew up in another galaxy about three times as far away from us as M101. Consequently this supernova was not as bright as the one in M101 but it occurred in this merging galactic pair of NGC 4568 and 4567, part of the Virgo Galaxy Cluster. The “host” galaxy is NGC 4568 which is the larger of the two and is where supernova SN2023ijd occurred. Elliptical galaxy NGC 4564 is seen to the right.
Although I started this project two days before the supernova was discovered, I missed a couple of days due to weather when the discovery actually happened
The discovery is credited to the All Sky Automated Survey for Supernovae based out of Ohio State University

Capture info:
Location: SkyPi Remote Observatory, Pie Town NM US
Telescope: Officina Stellare RiDK 400mm
Camera: SBIG STX 16803
Mount: Paramount MEII
Data: LRGB 22 hours

Thanks for looking!
Dave Doctor
4870 Mother Lode Trail
Las Cruces, NM 88011

In this fully annoted version you can see many galaxies populate this field including the elliptical galaxy NGC 4564 to the right. It is in the “vicinity” of NGC4567/8 at 57 million light years, just a couple of million light years closer.

So where is it located? Here you can see the red dot in the center is the location in the sky. It is in the constellation Virgo, visible in the Spring in the Northern Hemisphere about 40-50 degrees altitude on average. Unfortunately it’s quite small and dim. You’re not going to see much looking through an eyepiece. That’s why I do this 🙂

Ok NEXT time I will do the binocular review. Had to get this out there since it’s “hot off the press”

Thanks for reading!

DrDave

New image- Galaxy in a Bubble

NGC 3521 is a flocculent intermediate spiral galaxy located around 30 million light-years away from Earth in the constellation Leo.

A flocculent spiral galaxy is a type of spiral galaxy. Unlike the well-defined spiral architecture of a grand design spiral galaxy, flocculent (meaning “flaky”) galaxies are patchy, with discontinuous spiral arms. Self-propagating star formation is the apparent explanation for the structure of flocculent spirals. Approximately 30% of spirals are flocculent, 10% are grand design, and the rest are referred to as “multi-armed”. (Wikipedia)

NGC 3521 spans roughly 50,000 light years and features irregular spiral arms laced with dust, pink star forming regions, and clusters of young, blue stars. NGC 3521 is embedded in gigantic bubble-like gaseous shells which you can see surrounding the galaxy. Thirty six hours of data acquisition were intended to capture at least some of that shell structure . The shells are likely tidal debris from the accretion of one or more long gone satellite galaxies that have undergone mergers with NGC 3521 in the distant past.

Probably around 10 to 15 years ago a lot of interest in the astronomy community grew regarding stellar tidal streams associated with certain spiral galaxies in the so-called “local group” which includes the Milky Way. At least one model of galaxy evolution predicts they formed and evolved hierarchically though a process of mergers following the Big Bang. Little evidence of this consolidation was observed in galaxies located near the Milky Way until fairly recently.

Pro-am collaboration projects (i.e. projects with professional and amateur astronomer collaboration) were undertaken where deep amateur images of some of these galaxies were able to demonstrate the aftermath of galactic mergers in the form of stellar streams and gaseous shells. NGC 3521 is one of those galaxies studied so this is not a new discovery 😊 but nevertheless fascinating!

Image info:

Location: SkyPi Remote Observatory, Pie Town NM US

Telescope: Officina Stellare RiDK 400mm

Mount: Paramout MEII

Camera: SBIG STX 16803

Data: LRGB 14, 8.5, 6, 7.25 hours respectively

Processing: Pixinsight

Inverted NGC 3521 showing the gas shell structure a little more clearly

The inverted image above shows the gas shell structure a little better. Honestly I have some difficulty in certain cases distinguishing between “gas shells” and just bad flat calibration, but nevertheless since this galaxy has been studied fairly extensively, the gaseous morphology is well established. As it turns out there is at least one outer shell that extends quite a bit further into space. This is shown by the hatched line. You can barely see it in my image here.

Annotated image showing many galaxies in the field

Gold square in the center of this sky chart indicates the location of the galaxy

Through backyard telescopes, NGC 3521 can have a glowing, rounded appearance, giving rise to its nickname, the Bubble Galaxy. It is located in the constellation Leo shown above. At this time in the Northern Hemisphere it is visible in the southwestern sky after sunset. As you can see the region surrounding Leo’s hindquarters is host to a couple dozen Messier galaxies and these are typically larger and brighter than the Bubble Galaxy . As a result the Bubble doesn’t get quite the attention it probably deserves!

Thanks for reading!

DrDave