chiltonstar

I do quite a bit, eg Epsilon Lyrae:- Chris

A couple of craters with my 180 Mak/ASI220 mono from last week. Still learning! Chris

I spent some time on them last night with a range of EPs, and found that a 15mm Vixen SLV with my 180 Mak showed them up best. Higher or lower mag made them less visible, given the seeing conditions. I could see the four most prominent ones fairly easily, with hints of several others. As the seeing was passably ok, I popped my ASI220 mono on the scope for a quick pic, which shows the most obvious four. Nb - as you can see, I'm not a Lunar observer, or an imager. Chris

I have found that a 1.4x or a 2x Barlow works best with my 180 Mak, 3x is too much. As the scope is already f15 (more like f16 or f17 if you have extension behind the focuser, eg a flip-mirror), you may find that no Barlow is needed with less bright planets such as Saturn to give the best results. Chris

It was a spectacular sight, even to a non-lunar observer! Interesting shadow on the edge of Plato as well. Amazing to have some clear hours here before the Moon set behind a pine tree. Maybe the near-permanent rain and cloud have finally finished? Chris

Sounds like a nice, fun scope! Stelle Doppie has STF 1338 with mags 6.7/7.1, sep 1.0 and PA 320, and 57 Cancri 6.1/6.4, sep 1.6 and PA 309. Are these the figures you used, as the PA looks a bit odd on your sketches, although I always struggle with the upside down and reversed images from a newt?? Chris

From the January edition of S&T - great chart! Is this the one you have? I can copy it maybe if it doesn't cause a copyright issue..... If you use a goto or setting circles, you could catch Saturn and Jupiter higher in the sky maybe - the seeing and detail are often better IMO? Chris

If you could do it please Stu - many thanks! I always look down the S&T SkyGazers Almanac to find interesting events for the year, and then look them up on SS. Chris

Worth noting the close conjunction of Saturn and Jupiter at the end of twilight on December 21st 2020, Winter Solstice (that must be one for the astro*****s!) They are 0.1 degrees apart, the closest for 20 years or so and close enough to get in the same high power FoV, complete with moons galore. This is a SkySafari simulation:- Chris

....and nice it was too! Grab and go - Mak 127 with 8-24mm EP at x450. A nice blue disk cpd with the blue white of Venus. Chris

May well be worth a look tonight; Neptune is further from Venus, but at least the forecast is better. This is a SkySfari screenshot: Chris

Ditto here - a half hour spent Pup hunting tonight without success, although not surprising as the seeing to the SW was barely average. On the occasions I have spotted the Pup, the seeing has been excellent+ and it has usually been late Autumn when Orion is in a better position for me, well away from houses and heating. Chris

Great stuff Nick! Hazed up here last night, but Fri or Sat evenings look better, Deo volente! Chris

I await such a test on a real object with interest! Chris

Using Aberrator, or a DIY program. Chris

Despite the weather forecast here last night, it was actually glorious for a couple of hours (22:00 - 24:00). Using my 180 Mak I re-acquainted myself with AN's double Star of the month for January, 52 Orionis. A beautiful pair of whitish yellow nearly equal stars 1.0 arcsec apart. The seeing was good to excellent, so that the pair could be seen as a double at x270 (10mm ortho), and at x450 (6mm ortho), the pair could be seen as a clearly separated double with dark space between them (simulation below - visually slightly clearer than the sim.). The Trapezium was stable initially, but began to break up as Orion moved round to the west and began to sink over a house with a heating plume. The E and F stars were clear at x135, but not really separated below that or visible at much above x180. Always a thrill to see the Trapezium with all six stars clearly resolved against the background of M42, although M42 wasn't too impressive last night because of the nearly full Moon. The Moon itself was glorious - I spent nearly half an hour looking at the Mare Crisium and Cleomedes area - a huge amount of detail because of the oblique lighting. The Mak often offers amazing views of the Moon when conditions are right. Roll on some more clear skies.......... Chris

Obvious, but a little boring! Mind you, more evidence that nights are only clear when there is a full moon - as it is the first clear night for yonks. Chris

Yes, exactly Stu. The full aperture of 180 is maintained by having a slightly oversized mirror., meaning that the aperture really is 180mm. Chris

I think you'll find John that modern 180s with o/sized mirrors are actually 180 or very close. I've measured mine at 179mm and others in reviews have found the same. Chris

I have a couple of different ND filters (and an Nd filter) I use, mainly to avoid the effects quoted above of having one iris fully open, one closed, and trying to walk around the garden half blinded at night! Occasionally, the brightness of the Moon at low mag has triggered visual migraines (scotoma), which although fascinating are best avoided, even if they are harmless. Chris

I have two maks and it sounds excessive to me - both mine have a little backlash ands a small amount of image shift at high magnifications. I have heard (I have never tried it though) that winding the focus to one extreme and back again can reduce/eliminate focus shift - maybe worth trying, if not back to the supplier I think as it sounds as though something has not been tightened internally. Chris

I've been tempted to buy one of the adaptors that ZWO produce* (eg https://www.firstlightoptics.com/zwo-accessories/zwo-nikon-t2-adapter-suitable-for-all-asi-cameras.html, ) but notice a number of reviews eg on CN that point to difficulties in removing these from the lens once fitted. Manufacturing tolerances seem to be blamed. Has anyone any experience of these adaptors to confirm or not the tolerance issue? Many thanks! Chris * to use my range of Nikon lenses for imaging and guiding

The Sun was born again, but I didn't notice any naked folk frolicking about in the fields nearby. Shame these old customs die out. But at least it means the days are getting longer again! Chris

I've spotted it quite a few times now from the Oxford area, but the seeing has to be excellent++. Chris

An EP I've been quite impressed with is the 10mm Baader Classic Series Ortho (used with a 180 Mak giving x270). Very sharp and good contrast, but not a lot of eye relief. It has to be said though that Maks are fairly eyepiece-tolerant because of the long fl. Chris