Final 12" Session Before Moon Comes Around Again.

[Captain Scarlet]

This no-Moon cycle has been particularly fruitful, I think I've managed five productive dark-sky sessions with my 20-minutes-to-set-up 12" newt, including last night which was possibly a final short one before the Moon militates one of my smaller scopes instead, the Skymax180 or the Intes 150.

The forecast had been hovering between mainly cloud with possible clear patches, and clear with occasional cloud. In the event it was the latter, though I was worried about the 100% cloud cover as I was setting up just before dinner. It was due to pass though, and it did.

I set up in an easier-to-deploy place just outside the front (North) porch rather than my 50-metre trek in the field to the South, yielding great views from West to East via North but restricted altitude to the South. In the event, I spent most of the session looking South anyway: oh well.

I started off with M42/Trapezium, to gauge the conditions on the E and F stars, and indeed they were there straighaway and pinpoint, actually the best I've seen them. Seeing was obviously not bad, but the wind was NNW so occasional light gusts would shake things up a bit.

I've been keeping a list of potential targets stolen gleaned from others' (mostly John I think) reports on here, and I decided that cherry-picking from this list was going to be my source tonight.

M1 Crab nebula: Having seen this through binoculars a week or so ago, I found it here with my 10mm Delos at 183x. It was a decidedly obvious bright smudge, but annoying gusts of wind and my unwillingness to get the set of steps prevented me spending too much time looking for detail.

40 Eridani (HR 1325): From John's research this is a triple system comprising a sun-like star, a white dwarf and a red dwarf. Sure enough, there they all were! Obviously the third component at 11.something required effort between wind-shakes but it was clearly there. Tick!

Sigma Orionis: the multiple system that's become a regular for me now. Nothing difficult about its several triples and doubles, but gratifying and beautiful.

52 Orionis HR 1999: My notes suggested this was a challenging double, around one arcsecond, so when I found what appeared to be a single 5th mag star in my field I thought it could be it. At 183x I couldn't make a double at all. I put in the 6mm and 305x still didn't decide it, though I could perhaps see some elongation. No breakdown in the image though, all still very sharp. So I put in my almost-never-used Delos 3.5mm for 522x, and there it was, a clear pair of tight white dots. It was just like a more difficult version of one end of the Double-Double. Funnily enough when a bit of breeze did come through to give a gentle shake, it was even more apparent: two parallel white lines buzzing around the field of view until it settled. And still no image break-down, so seeing very good. Tick!

With the 10mm back in (183x) I moved to the Flame Nebula, which was apparent, and on to the Horsehead. I checked SSpro to see exactly what orientation and which stars I was looking at, and it seems the HH is exactly framed by a quadrilateral of equal-brightness stars, and I was looking exactly at it! Could I make it out. Maybe perhaps-perhaps just, but once again I won't take the tick. I'll need to be sitting down and staring before I can confirm it I think.

With my success at 25 Orionis I had a go at Sirius, even though it was behind a tree, but haha no chance. Diffracted to hell by all the branches. I did console myself with Rigel though, and even put the 3.5mm back in for stupid magnification again. I was rewarded with miles of empty space between Rigel and its companion, and a very pronounced blue colour to it too.

I quickly finished off by pointing at the Pleiades and sticking my DSLR into the focuser to get a few shots to be able to measure exactly by what factor my Paracorr2 acts as a Barlow.

That was it for me, I could see clouds coming in from the North so a decent couple of hours.

Cheers, Magnus

 

[Jiggy 67]

Great report. You’ve got to love Sigma Orionis, last time I looked at X280 mag, could clearly see a second binary in the same fov, HD294271, lovely sight

[Ships and Stars]

Great session from home Magnus! Did you use the 10mm and Hb filter for the Horsehead? I seem to have a lot of luck with my 17.5 Morpheus and el cheapo 25mm Revelation plossl, those give a much larger exit pupil in the 3.5 to 5mm range depending won which scope I'm using. I could just detect the HH from home last night with the 12" f4.9 flextube dob and 17.5mm Morphues/Astronomik Hb filter. 

May I ask which bins you used to see M1? That's impressive! Never tried M1 with binoculars. 

Sounds like you had a good run of nights there 👍

[Captain Scarlet]

Hm I think you might have spotted a fatal flaw in my account. I’ve only recently first seen the crab, and on reflection I recall using my baader rdf to get me to the vicinity. Which means I must’ve been using my Intes Mak not my bins. Oops apologies. But it does set me a challenge!

[John]

Very nice report Magnus !

I can't wait to get my 12 inch dob out again

You seem to be looking in just the right place for the Horsehead. I've spent quite a lot of time looking at that small patch of sky over the past few winters. Most of the time with no sign of it but when I have managed a glimpse it has been with the H-b filter on the end of the eyepiece.

Such a subtle and challenging target - probably about the hardest thing that I've ever observed when I think about it.

 

 

 

[Ships and Stars]

21 minutes ago, Captain Magenta said:

Hm I think you might have spotted a fatal flaw in my account. I’ve only recently first seen the crab, and on reflection I recall using my baader rdf to get me to the vicinity. Which means I must’ve been using my Intes Mak not my bins. Oops apologies. But it does set me a challenge!

No worries! I've some 20/40x100 bins, that would be a good challenge, I'll give it a shot and see next chance. My best view of the cocoon nebula was through filtered bins, so it's possible. I think you said you've dark skies where you live, the horse head is possible there with a 12", but it will almost always require an Hb filter to tease it out. I've seen it with direct vision using a nebustar UHC type filter, but only in the 20" from a dark site and the Hb was better. Like John said, it's very subtle to put it mildly.  More a matter of detecting its presence, rather than really seeing anything. The flame nebula is actually more interesting, but it's great fun to bag the HH. 

Edited January 17, 2021 by Ships and Stars

[Captain Scarlet]

My only filter at the moment is an Oiii, and for some reason it never occurs to me to use it when I’m observing.

I think an H-b and a UHC filter have just risen to the top of my wish-list. (Are they the same thing? H-b I assume is Hydrogen beta, and UHC a mix of wavelengths?)

[John]

Having tried for the HH quite often and not got it, I came to the conclusion that the trick was going to be to be able to see / detect the underlying streak of emission nebulosity IC 434 which Barnard 33 (The Horsehead) is set against. To me, when I eventually did manage to see it, the Horsehead looked like a place where an indistinct "bite" of IC 434 was missing  I think this is where the H-b filter helps - to tease out this faint HII emission nebula so you can see where it is, and, crucially, the small patch where it isn't. And that is the Horsehead Nebula.

A UHC passes both O-III and H-b band widths so can help but the H-b just isolates that one bandwith so is a little more of a helping hand with this task. The O-III bandwidth does not seem to help with this one.

As dark and transparent skies as possible are another very important factor as are eyes that have become as dark adapted as they can be. I even stopped using my Rigel finder for a couple of hours when I was doing serious Horsehead searching. No light at all anywhere near my eyes for quite some time.

All that to just about visually detect a small patch of blackness against slightly less black, blackness. We must be a little mad

 

Edited January 17, 2021 by John

[Ships and Stars]

Just now, Captain Magenta said:

My only filter at the moment is an Oiii, and for some reason it never occurs to me to use it when I’m observing.

I think an H-b and a UHC filter have just risen to the top of my wish-list. (Are they the same thing? H-b I assume is Hydrogen beta, and UHC a mix of wavelengths?)

Picking the right filter is key. An OIII is excellent for many objects, you'll be amazed at the Rosette, Veil, M97 and so on, it's a must have for most emission nebulae. An Hb is useful for most dark or reflection nebulae, the cocoon, California nebula and definitely the horsehead. The HH is basically impossible to see without any filter, unless under exceptional conditions with a very large scope, so I have heard. I've never seen it without a filter. The UHC is as you indicate an all-rounder of sorts, lets in more of the light spectrum but increases object contrast too. For UHC filters, I rave about the TeleVue nebustar, though it blocks red light unlike normal UHC filters but gives better views IMO. My other filters are Astronomik Hb and OIII. Not cheap, but they're high quality with close control over light transmission. I'm no filter expert, but there are some here that definitely are. John, Don Pensack, Scarp 15, jetstream are all highly knowledgeable, plus others. Filters for visual use is a popular topic but most agree, an OIII, UHC and Hb are must haves for nebulae. I've been meaning to try a cheaper filter against the astronomik or lumicons to see if there's much in it, but from what I've heard, those two (and the televue filters which are made by astronomik) are the way to go.

[jetstream]

5 hours ago, Ships and Stars said:

The HH is basically impossible to see without any filter, unless under exceptional conditions with a very large scope, so I have heard

I see it easily no filter with my 15" and the 24" that much easier again. With the Hb in these scopes the object is no challenge at all. These observations mandate excellent transparency and darkness.

Back when I started on this object with a 10" it seemed near impossible...it to me a long time to see it. My still favourite combo, borne out of success, is the 25mm Televue plossl and the Astronomik Hb. If I was using a 12" dob these would be my goto selection.

I easily see IC434 in my fracs and yet Ive not been able to tease out and confirm what must be a pimple sized notch of the HH in these scopes.

Re: the 25mm TV plossl idea- I just copied what some serious USA observers reported using with success- and they were right.

@Captain Magenta give the 25mm plossl a try with a Hb, a 1.25" will do the trick and this narrow TFOV combo will keep Alnitak at bay in your scope.Good Luck!

[jetstream]

5 hours ago, Ships and Stars said:

An Hb is useful for most dark or reflection nebulae,

I don't find that an Hb or any filter of any type works on dark or reflection nebulas.Just me...

Edited January 17, 2021 by jetstream
spelling

[Whistlin Bob]

Wonderful report- really enjoyed reading it- also gave me a strong longing for my 14" to come out for the first time since November. There's a few favourites in your list I haven't seen yet this season- especially m1. The HH is an odd one. An Hb filter is very helpful for it, and UHC helps too. I had a pretty clear sight in Cumbria once, and some very marginal views at home. It's a funny object because, as John says, it's more darkness in a nebula bank that you're looking for than anything else. 

Edited January 18, 2021 by Whistlin Bob