Here’s Mars 2020’s target. (02 Aug 2020)

 General Commentary, Mars, Planet, Solar System  No Responses »
Aug 032020
 

With the Mars 2020 spacecraft on it way, I thought it would be good time to take a look at where its going. Actually, I couldn’t take any other useful images with a nearly full Moon. At these times the planets are the only targets that can reliably compete with the sky’s brightness.

This image was taken on the morning of 02 August when the Moon was 98% lit and Mars 86%.

This is an image of Mars taken through the PTO's telescope. The planet is shown south up in the standard orientation provided by a Newtonian reflector telescope. Of course this view puts the bright white southern ice cap at the top. The rest of the planet is a rusty orange color with large areas of dark surface markings.

Mars
[(V) R:2736×0.17ms;
G:2738×0.26ms;
B:2739×0.60ms]
This image is an accurate illustration of Mars matching the picture taken of Mars through the PTO's telescope. The illustration shows Mars' equator, central meridian and a line showing the planet's axis of rotation with North indicated.

The Mars illustration is courtesy of WinJUPOS.

The southern polar ice cap is obviously visible. The slightly brighter area in the upper right quadrant is the Hellas basin, reportedly the largest impact basin in the solar system. Below that is the dark Syrtis Major region that extends down past the equator. Jezero crater, the targeted landing site for the Perseverance rover, is all the way down the dark Syrtis Major formation on the left side of the point.

I am really looking forward to Mars’ 2020 opposition on the 13th of October. Right now Mars’ apparent angular size on the sky is 14.7 arc seconds. At opposition it will appear 22.3 arc seconds wide, a 51% increase in size.

For an explanation of caption information see exposure data.

 Posted by at 18:30

Going to pieces – C/2019 Y4 (ATLAS)

 Comet, General Commentary, Solar System  No Responses »
Apr 172020
 

This image shows comet C/2019 Y4 (ATLAS) as it continues to break up the closer it gets to the Sun. This is a single 600 second exposure with the mount’s movement matching the comet’s motion. Two primary fragments are obvious but I have convinced myself I can see at least one more bright spot trailing the other two in the comet’s tail.

C/2019 Y4 (ATLAS) [CV:1x600s]

I took advantage of a software capability I hadn’t used before to take this image. APCC (Astro-Physics Command Center) is software that sits in between the user and the AP mount, in this case an AP1600. It has the capability of using data generated by the JPL HORIZONS web based tool. That tool takes the orbital elements of an object and generates an ephemeris of the desired solar system object based on user specific parameters.

I use the tool due to its extreme accuracy. It is also convenient since JPL lists the PTO in its list of observatories. I had always used the output ephemeris manually before, printing out the table of data, reading the objects location at the current time and manually sending the mount to that location. This is the first time I had the software read the data directly and adjust the mounts tracking rates to match the comet. I am pretty sure this will not be the last time I use HORIZONS.

 Posted by at 16:34

Beehive cluster (M 44)

 DSO, General Commentary, Open Cluster, Wide FOV  No Responses »
Apr 072020
 

I have been testing a new optical configuration to give the PTO the ability to record larger FOV images. Mounting my Nikon D90 to a 80mm f/6 apochromatic telescope gives a 2.9°x 1.9° FOV image. The resulting 5.26 sq° image is 97% larger than the standard science image used for asteroid/comet analysis. The size of the camera chip is large enough though that significant distortion is visible at the extreme corners of the image. As you can see the stars are ‘stretched out’ with each pointing towards the center of the image. This is known as pincushion distortion. A field flattener will need to be added to correct this problem.

The test target is a fairly large open cluster. It lies in the center of the constellation Cancer and is known as the Beehive cluster. The current population count is about 1,000 stars although only the brightest form the naked eye object. This is one of the first objects observed by Galileo when he first turned a telescope to the sky. He counted 40 stars.

Beehive Cluster (M 44)
[M:4x60s]

The compressed display makes the image background much brighter than it should be. Click on the image for a larger more accurate view. This will also make the corner distortion easier to see.

 Posted by at 14:24

Almost there

 Comet, General Commentary, Solar System  No Responses »
Mar 222020
 

For the past two weeks I have been preparing for the new science camera. It uses different cabling and doesn’t use water to assist the cooling. So I had to dismount the scope and disassemble the mount to remove the old cabling and the water plumbing. I then installed the new control cables and took the opportunity to upgrade one of the USB hubs and cabling to USB3 for the planetary camera. Then everything was put back together and the scope remounted.

The final part of the new science camera system arrived yesterday (the 21st). I took the filters out of the old filter wheel and installed them in the new one. The new filter wheel only holds 8 filters so I had to choose which two will go into storage. The next step was to mount the filter wheel on the camera and mount to the scope. The new software was tested yesterday afternoon and there was no apparent problems.

Just after midnight the skies started to clear so I powered everything up and took a shot at a random spot in the sky. A couple of jogs to the focuser brought the image somewhat close to focus. So, here is the new camera’s first light image.

This image has no processing, is manually focused, the scope is out of collimation and some lights were still on in the dome room. But it was good enough to tempt me to take a look at a brightening comet.

This is comet C/2019 Y4 (ATLAS). The comet is currently inbound, above the plane of the solar system and has just crossed the orbit of Mars.

The image is a stack of fifteen 60 second exposures registered to the comet. There were high thin clouds passing and that can be seen in the star streaks and the mottled background. But it is enough to prove the system works and that the PTO is getting close to being back in operation.

 Posted by at 16:33

“Journalistic nonsense”

 General Commentary  No Responses »
Dec 252019
 

Today I read a quote in the January 2020 issue of Sky & Telescope magazine. The quote is by Dr. Roy K. Marshall. He was an astronomer that worked at the Franklin Institute’s Fels planetarium and the first director of the Morehead Planetarium, Chapel Hill, N.C. He also hosted the popular 15 minute television show The Nature Of Things that ran on NBC from 1948 to 1952.

Unless astronomers assign themselves the task of stopping journalistic nonsense about astronomy, surely no one else is going to do the job.

I couldn’t agree more. So, I am sure that this August when asked, once again, about Mars being the size of the full Moon, I will, once again, have to counter “journalistic nonsense”.

 Posted by at 11:54
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