any astronomers here?

[HughP3]

getting back into it after 10+ years away. did not realize how much I missed it…. very soothing to the soul.

 

[astrotoy]

Very nice. How big is the refractor? Looks like a very good sized one for an amateur instrument. Also takes time to set up the equatorial mount accurately. Larry (retired astronomer)

 

[HughP3]

Very nice. How big is the refractor? Looks like a very good sized one for an amateur instrument. Also takes time to set up the equatorial mount accurately. Larry (retired astronomer)

hi larry its a APM 152ED 6 inch doublet. some say semi-apo but star tests show chromatic aberration minimal, I say Apo. i love refractors. mount is a Mach2 from Astro-Physics, first AP mount i have owned and it is exquisite. i used to do astro photography but that just took too much time and effort, it’s difficult. this scope is very reasonable for an Apo but as i cannot control myself i ordered my forever scope a TEC 180FL (Florite triplet), about a year wait. looking into night vision setup which increases aperture some say up to 100x. thats a big big scope…

 

[astrotoy]

Very nice. A triplet is a big deal. When I was in college at Harvard we had a 15 inch refractor from the mid 1800's - the largest telescope in the US during that time. I did my senior thesis using the school's 61" reflector. In grad school at Cal (Berkeley), we had both a 36" reflector (I used that for measurements on my PhD thesis), and a 36" refractor (the second largest refractor in the world after the 40" Yerkes refractor). The big telescope is the 120" reflector, which at the time was the second largest telescope in the world after the 200" at Mt. Palomar. That was back almost 60 years ago. Today, lots of bigger telescopes, including many with segmented mirrors.

I was a founding member of the Board of the Chabot Space and Science Center in Oakland, CA. We have two wonderful refractors. The first from the late 1800's is a nine-inch Alvin Clark refractor (Clark would later do the lens of the Yerkes refractor). The second is a 20" refractor with a lens by John Brashear from 1914. The larger telescope is named Rachel and the smaller telescope Leah. If you know the Biblical story of Jacob and his two wives - Leah was the first, but Rachel was the one he really wanted to marry.

Larry

 

[HughP3]

Glad to meet a real Astronomer! I have heard of these huge refractors, one day i hope to look through one. Your story is amazing, your obviously a gifted guy. Would enjoy a sit down with you. Are you still active the field?

Its a 152mm or 6 inch. I have a 180mm or 7”on order. Its as big as i care to lift! You asked about setup and polar align. Its really easy with this new stuff. The mount comes with a very accurate polar scope with illuminated reticle. i level the mount then use free software called PS align pro on my iphone. It replicates my reticle and using my gps location and date/time calculates the earths procession and displays where to put polaris on the calculated reticle. I adjust the mount in dec and ascension until polaris is placed in the reticle in the calculated right spot. i then slew to a known star center and tell the mount to resync. It calculates and stores the pointing error. All done. The best way if i had a permanent setup and using pc control software would be to use a camera that plate solves stars in various slew positions. the pc software calculates the error. Very accurate goto from then on.

Total setup from storage to fairly accurate goto is about an hour taking my time. Tear down and storage is about 40 minutes or less. I do love the hobby. Its awe inspiring.