Earthshine - Gibbous Moon - New Scope

Last night was 2nd light for a new telescope. So naturally I had to check out performance, etc.

Besides checking out a few DSOs: NGC3077 (stumbled across accidentally), M81, M82, M97, and M108)under bright moonlight. The moon itself became a target. After the moon had drifted almost entirely out of a high-powered FOV I thought I saw the following limb via earthshine. To rule out a stray reflection, glare, etc. I went back and repeated the observation a few times - even resorting to the use of a different eyepiece. Yep, sure enough, I was seeing earthshine! The new scope (and my sky) passed an unplanned, unscheduled 'test'.

A quick search will reveal that earthshine on a gibbous moon is nothing new.. Nevertheless, spotting it accidentally with a new telescope on the 2nd night out can only be interpretted as a 'positive'.

It's a bit early to give the new scope a name, but "Earthshine" and "Moonshine" are early possibilities. . .

Meanwhile, tonight is expected to be clear and bright!

Sketcher,
To sketch is to see.

On Saturday, June 27, 2015 at 1:08:12 PM UTC-7, Sketcher wrote:
Last night was 2nd light for a new telescope. So naturally I had to check out performance, etc.

Besides checking out a few DSOs: NGC3077 (stumbled across accidentally), M81, M82, M97, and M108)under bright moonlight. The moon itself became a target. After the moon had drifted almost entirely out of a high-powered FOV I thought I saw the following limb via earthshine. To rule out a stray reflection, glare, etc. I went back and repeated the observation a few times - even resorting to the use of a different eyepiece. Yep, sure enough, I was seeing earthshine! The new scope (and my sky) passed an unplanned, unscheduled 'test'.

A quick search will reveal that earthshine on a gibbous moon is nothing new. Nevertheless, spotting it accidentally with a new telescope on the 2nd night out can only be interpretted as a 'positive'.

It's a bit early to give the new scope a name, but "Earthshine" and "Moonshine" are early possibilities. . .

Meanwhile, tonight is expected to be clear and bright!

Sketcher,
To sketch is to see.

So... what make & model is the new guy?

\Paul A

The make of the new guy: Explore Scientific
The model: 152mm f/6.5 achromatic OTA (AR152)

An earlier version included a shorter dew shield along with a case.

Last night I started the evening by checked out Jupiter and Venus (less than 17 degrees in altitude). Seeing was pretty bad. Nevertheless, at 200x with an 80A (blue) eyepiece filter Jupiter's GRS was evident. I was able to identify each of Jupiter's moons by their relative sizes and brightnesses. Ganymede and Callisto were clearly larger than Io and Europa. With the filter, the GRS was pink. Callisto was steel-gray. Some blue and purple surrounded Jupiter, but it was easy to lose sight of and forget about while looking for more important details.

Venus at 330x without filters was awesome! (or horrible depending on one's point of view). The large, bright, fat, (well defined) yellow crescent was bathed in a blue and purple halo. Earth's atmosphere added even more color! Venus's southern horn-tip was accented with red while its northern horn-tip sported a blue accent. I'm sure most school children would have tremendously enjoyed the sight!

Next: I succeeded in tweaking the push-pull collimating screws - improving the relationship between the inside and outside focus star test patterns - eliminating a touch of astigmatism. I had never collimated a refractor before, but I have collimated schmidt-cassegrains and Newtonians (refractors are different - duh!) For reference, I have Suiter's star test book. Tools included a 2nd magnitude star, a 3.8mm eyepiece and a 3mm allen wrench.

I checked out Saturn both before and after collimating the scope. I made sketches of the inside and outside focus star-test patterns before and after as well. Seeing had improved quite a bit for Saturn (at a 24 degree altitude). Various magnifications were tried. I eventually dropped down to 110x and was able to see Titan, Rhea, Dione and Tethys. Other than Titan, these moons were extremely tiny pin-points. The shadow of the planet on the rings was easy. The rings passing in front of the planet were easy. Cassini's Division was evident, but not as contrasty as with Excalibur (5" apo) or Iron Snowflake (12" Newtonian). I had to look for chromatic aberrations in order to notice them while observing Saturn.

After this third night my impressions: I'm (pleasantly) surprised at the capabilities of a short-focus, 6-inch achromat - especially for lunar and planetary observing. It's definitely a good scope to use for outreach and public viewing. I purchased the scope primarily for low-power, wide-field, dark-sky deep-sky observing. A 27mm Panoptic eyepiece will likely be spending much of its remaining life in the scope's stock 2-inch 99 percent reflective diagonal.

I've been equally impressed with Explore Scientific - their concern for their customers, their concern for their products, etc. They've found a way to combine inexpensive Chinese manufacturing with their own high standards for product features and quality control.

My only regret: That scopes like this, priced like this, weren't available many years ago.

Sketcher,
To sketch is to see.

On Saturday, June 27, 2015 at 5:01:35 PM UTC-6, palsing wrote:
So... what make & model is the new guy?

\Paul A

On Tuesday, 30 June 2015 05:13:13 UTC+2, Sketcher wrote:
Yes, I've heard good things about minus-violet filters. One of these days I'll probably get one, but I'm not in any hurry. My AR152 will be used mostly for deepsky observing.

While looking at 6-inch achromats the CR150/8 OTA was considered . . .

I've had my share of cold weather experiences. An important lesson was learned over 30 years ago when I brought an 8-inch SCT inside (without 'boxing it' first) on a minus 20 deg. F. night. My coldest recorded observation/sketch was of a comet when the temperature was minus 50 degrees F. It used to get cold in Montana!

I like the picture of your CR150. Now that's a *real* telescope!

I didn't realize how convenient and useful an OTA handle could be until I had to mount and dismount my new OTA - It's good to have a handle!

Like yourself, I'm considering building an alt-az mount. For low-powered deepsky sweeping it would be more practical and convenient than an EQ.

My f/6.5 OTA weighs about 5.5 pounds more than a CR150 f/8. Maybe I need to check it with a magnet :-)

Sketcher,
To sketch is to see.

Good grief! Your chilly experiences completely dwarf my [rather brief] -25C record on the back lawn!
I couldn't keep the eye lenses clear of ice from my breath for more than a few seconds despite rotating the eyepieces through my duvet jacket pockets.

I fitted a heavy ring weight inside the focuser end of my CR150 to get a more aesthetic balance point.
Then quickly took it out again as it exceeded my ability to lift the telescope safely and repeatedly above my head in the dark!

Handles can get in the way of the tube rings when the Eq. mounting saddle is 2' long and the "stumpy" OTA is very nose-heavy.
The baffles can also interfere with the handles' fixing screws.
Or make them impossible to reach!

It also pays to invest in stainless steel handles and fixings to avoid rapid corrosion.
Some U-form drawer handles are just satin-chromed iron or steel.
Electroplated screws and parts on any telescope are just rust waiting to happen.

Have you come up with a suitable name for your latest, optical acquisition?
I can think of several derogatory names based on its being "dimensionally challenged."
But perhaps I'd better keep them to myself. ;ø]]

I did the same (added weight inside the focuser end) to an old 60mm alt-az refractor so it would be balanced. After painting the scope yellow it was named "Buttercup".

The only place on my new OTA that attracted a magnet was the steel (stainless I presume) hand-hold beneath the focuser end.

I'm still working on a name for the new scope. Feel free to offer suggestions! Evidently first light took place on Charles Messier's birthday! "Space Ghost" is a name that doesn't seem to be going away very easily, but it's not a sure thing yet.

Sketcher,
To sketch is to see.

On Tuesday, June 30, 2015 at 12:38:32 AM UTC-6, Chris.B wrote:
Good grief! Your chilly experiences completely dwarf my [rather brief] -25C record on the back lawn!
I couldn't keep the eye lenses clear of ice from my breath for more than a few seconds despite rotating the eyepieces through my duvet jacket pockets.

I fitted a heavy ring weight inside the focuser end of my CR150 to get a more aesthetic balance point.
Then quickly took it out again as it exceeded my ability to lift the telescope safely and repeatedly above my head in the dark!

Handles can get in the way of the tube rings when the Eq. mounting saddle is 2' long and the "stumpy" OTA is very nose-heavy.
The baffles can also interfere with the handles' fixing screws.
Or make them impossible to reach!

It also pays to invest in stainless steel handles and fixings to avoid rapid corrosion.
Some U-form drawer handles are just satin-chromed iron or steel.
Electroplated screws and parts on any telescope are just rust waiting to happen.

Have you come up with a suitable name for your latest, optical acquisition?
I can think of several derogatory names based on its being "dimensionally challenged."
But perhaps I'd better keep them to myself. ;ø]]