13 May - Big Dobs continued intergallactic journey with Photonis Night Vision...

[alanjgreen]

Date: Sun 13th May 2300-0245am       
Scope: 20” f3.6 Lukehurst Dob with Paracorr (fl = 2089mm & f4.1). Night Vision: PVS-14 with Photonis 4g INTENS.
Eyepieces: 55mm (f2 x38), 35mm (f3 x60), 27mm (f4 x77), 18.2mm (f5.8 x115). Filters: Astronomik CLS (Visual IR pass), Baader 610nm Red, Astronomik UHC, Astronomik 6nm Ha CCD. Astronomik 12nm Ha CCD.

 

UK in for a Clear Spell!

The next few nights are forecast clear for us in the UK, so I was able to get out last night for a bit more galaxy experimentation…

 

Leo under Darkening Skies

Obviously at this time of year the problem is that it does not go dark until very late, even at 2300hrs I could only see the main constellation stars visually, but as I have learned “that won’t stop the Night Vision from seeming MORE…”
Tonight, the plan was to compare unfiltered with the Astronomik UHC views of face-ons using the 55mm Televue Plossl.

 

M66 – (Unfiltered) Eventually, after some playing with the “gain” (of the PVS-14) and using averted vision techniques, I got to see the “S” shape of M66. The best method to get the arms out seemed to be to turn the gain down low then inch it back up. At some point the arms would come and then stop there. It was hard to hold the arms in view for very long though.  (UHC) With the UHC fitted, the background was darker and presented a better view. The arms could be teased out as above but to a lesser extent.

M65 – (Unfiltered) Presented a “swirling halo” with a black streak running under the front edge. (UHC) Similar view with the UHC too.

NGC3628 – Long wide side-on with thick black lane running through. Slightly better unfiltered.

NGC4535 – This is going to be a good one at the right time of year. It has a beautiful intricate arm structure. Unfiltered I could see a small circle created by the arms around the core. With some time and averted the outer arms did come and go! Again, slightly better unfiltered.

M99 – (Unfiltered) I could see one clear arm swinging out over the top. With some time and averted then I could pick out the two arms underneath too. UHC not tested.

M100 – Two long spiral arms coming and going. I did not get to see them as well as the other night

M88 – (Unfiltered) There was a definite “swirling” effect seen within the halo along with tiny black bits within the halo. I could see a longer black area over the top.

M91 – (Unfiltered) Showed a bright central bar with two black sections on either side. No arms seen.

M58 – (Unfiltered) Showed a bright central bar with hints of tiny arms close in to the bar.

 

Time for Ursa Major

M108 – (Unfiltered) Long thin with varying brightness and texture. A nice bright view. Will visit again with the 35mm tonight!

M109 - (Unfiltered) Bright central bar. Delicate arms hinted and occasional sighting of two very thin arms leaving the central bar near a close in foreground star. Black areas to each side of bar. Occasional circle arm seen.

M106 – (Unfiltered) Big bright halo in a sweeping “S” shape. Swirling effect visible in the halo. Lovely.

M51 – (Unfiltered) Wonderfully sharp and clear view of the arms and the black intersection within the halo of the nearby NGC. Specs of tiny black dust lanes within the spiral arms (although I was seeing them more towards the side of the arms !!) Clear view of the bridge.

M101 – (Unfiltered) Lovely arm structure on offer! Three main arms with real definition in shape. One arm has a separate section that breaks off. Internal NGCs seen to both right & left extremes.This view was “up there” with my initial view of M101 when I first used my night vision.

I had had a couple of “fails” on M101 recently and now I know that this was due to inaccuracy in my Nexus alignment. I was in fact viewing a nearby galaxy on those other night rather than M101 itself! (I need to choose some alternative alignment stars tonight!). Golden rule = If it doesn’t look like M101 then it probably is not M101.

M101 – (UHC) Lost the outer arm details. Arms still there in centre section. (610nm) Nothing much on show.

Conclusion = Unfiltered > UHC > 610nm. I also tried the 35mm Panoptic but the arms were “less” than with the 55mm Plossl.

 

Time to Scan the Milky Way at x1 with the 12nm Ha filter

As my favourite galaxies continued their drift into the West, I decided it was time to put the PVS-14 direct to my eye and scan the Milky Way. I installed my Astronomik 1.25” 12nm Ha CCD filter into the front lens and placed my Sacrificial Window over the top to hold it in place then looked up.

After focusing the PVS-14 and turning the gain all the way up, I was awed at the great Nebula on offer...

Within Cygnus I could see the North American (Faucet) nebula as bright white, I could see the cloudy blob of the Elephant Truck to its left. Within Cygnus the intricate detail of the Gamma Cygni was wonderful.

But the best surprise came as I scanned South and bumped into four bright nebulosity blobs in Sagittarius (Eagle Nebula for one!). I am going to try my 1.25” Castell UHC tonight and see what that does to the view of the Milky Way…

I noticed that Andromeda was much harder to spot with the Ha filter installed. It was massive the other night at x1 with no filter.

 

Clear Skies,

Alan

[Olli]

Great report Alan was clear here as well but didn't have the chance to get out, I need to stop reading your reports making me want to get a bigger scope