A Solo Night at Kaʻohe

A dark clear night at Kaʻohe, just the thing I needed. A telescope… A dark sky.

The start of a dark night at Ka'ohe on the side of Mauna Kea
The start of a dark night at Ka’ohe on the side of Mauna Kea

There had been plans of a few friends from work, but with a virus rampaging through the crew a social event did not seem like a great idea. Will have to do the invitations another time. This evening would be a solo run.

No big production… Toss the gear in the vehicle… The Nexstar 11″ ‘scope, a few munchies and a thermos of hot tea, a table, a notebook, and go.

The night was nearly perfect, no wind, not all that cold, a few wisps of cloud that dissipated after sunset.

I would work the southern horizon this night, as low as I can go from 20°N latitude. From the Kaʻohe site due south is right over the summit of Mauna Loa. Just above the shadowy outline of the caldera I would catch stars and galaxies as they transited. Constellations unknown and inaccessible to northern observers… Pavo, Grus, and Phoenix. Some of the objects I observed were in the lower -60° declinations…

φ2 Pav Pale yellow, no companion noted, φ1 Pav is visible 33′ west

NGC 7582 Bright and obvious, extended 5′ x 2′ northwest-southeast, brighter to the center without a notable core, NGC 7590 and NGC 7599 visible 10′ northeast, NGC 7552 visible 28′ southwest, the Grus Quartet makes an entrancing field with four bright galaxies

NGC 45 Quite faint and diffuse, difficult, about 5′ diameter, a slight brightening to the center, a 10th magnitude star in the southeast quadrant, the 7th magnitude star HD 941 is about 5′ southwest

NGC 7155 Small, faint, round with a stellar core, at the center of an east-west 15′ arc of 11th to 12th magnitude stars

Andrew Cooper, 7 Oct 2023

A good night out with a telescope, packing it in about midnight as to not totally wreck my sleep pattern. Still, I got in five hours of observing.

Battery Corrosion Again

Leaking alkaline batteries, the bane of our portable, battery powered existence. All too many times I have found myself repairing electronic devices damage by leaking batteries, or just junking the gear when the damage is too severe.

Corrosion damage in the base section of a Celestron 8SE mount
Corrosion damage in the base section of a Celestron 8SE mount

This time the device in question was just a bit too valuable to dispose of despite fairly extensive damage.

A Celestron Nexstar 8SE telescope.

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Holoholo – A 10.1” f/4.5 Travel Telescope

Living in the islands provides excellent observing for an amateur astronomer such as myself, but there are drawbacks. I do miss the large star parties, getting together with hundreds of other observers to see other telescope setups, to learn, and to share the sky.

The 10" f/4.5 travel scope Holoholo
The 10″ f/4.5 travel scope Holoholo

Thus I have made a habit of traveling to the mainland once in a while to attend one of the larger star parties. This year I will again attend Oregon Star Party. It has been a while, the last time was 2017, the year of the total solar eclipse.

Traveling from the islands to a star party makes it a challenge to bring a large telescope. Last time I borrowed an 11”, not a bad solution, it worked, but it was not my ‘scope. This time I was determined to realize a long considered idea, to build a substantially sized travel telescope. Thus Holoholo was designed and built, a 10.1” f/4.5 travel ‘scope.

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Oregon Star Party 2023

A large star party is an experience worth seeking out… Hundreds of people, hundreds of telescopes, all under a dark sky.

A large dobsonian set up at Oregon Star Party 2023
A large dobsonian set up at Oregon Star Party 2023

A star party is a meeting of geeks. Technical talk of optics, electronics, and fabrication techniques like 3D printing abounds. In the afternoon and evening you will find small conversations in the shade, pull up a chair and join the discussion.

The plan was something I had executed successfully before… Fly into Portland, spend some time with my folks, then borrow the family camper for the trip out to the Ochoco Mountains for the star party.

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Using the ZWO ASI2600MC Camera

Due to a plan that failed I ended up with a borrowed astro camera for a couple weeks. Since I have it I may as well play with it a bit.

The Orion Nebula M42
The Orion Nebula M42

The camera is the ZWO ASI2600MC Pro, a one-shot color camera specificaly for astrophotography. I have the ASI1600MM Pro a monochrome camera set up with a filter wheel, but have never really had a chance to use one of the modern one shot color cameras.

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A Bahtinov Mask for the TeleVue 76

For some reason I have gotten along without a focus mask for the TV-76. Need to fix that… Done.

A 3D printed Bahtinov focusing mask for a Televue 76mm telescope
A 3D printed Bahtinov focusing mask for a Televue 76mm telescope

Just a quick project, about half an hour to design and four hours printing. First print a pleasing success, a completely functional part.

A Bahtinov Mask is used to get a precise focus, something I wrote about a few years back.

A 3D printed Bahtinov focusing mask for a Televue 76mm telescope
A 3D printed Bahtinov focusing mask for a Televue 76mm telescope

For this mask I used a public bit of OpenSCAD code from Jens Scheidtmann to generate the mask pattern, just tuning it for the correct sizing and performance with the TV-76. I added my own version of the support collar, making it a bit neater with fillets and properly sized to slip over the TV-76 glare shield.

You can download the SLT file for the mask from Cults3D if you need to print your own.

The part is one of a half dozen parts I have designed and printed over the last few weeks to reassemble the photo rig. A new guide camera mount, a mount for the ASI Air computer, a new glare shield for the guider, etc., etc… The utility of 3D printing a game changer for me.