IC 434 - Horsehead Nebula

[Matthieu (Matt)]

I had a great time last night with the Horsehead Nebula.

As I was panning through Orion without filter in my bortle 3 or 4 skies around midnight, I noticed that the Flame Nebula was visible with direct vision in my 16”. I took that as a sign to try for IC 434 and the Horsehead.

I screwed on my new to me H-Beta filter and lo and behold could immediately see the gaseous cloud. I now understand why others have referred to it as a dagger.

Spending a bit more time with averted vision, a black notch perpendicular to the dagger and going about half through became very apparent. I took note of closest stars and validated in Interstellarum at the scope and Stellarium once I got back inside.

I had some focusing issues with 1.25” eyepieces so only used my 30mm for 60x and 12.5mm for 144x). 144x was too dim with a 2.8 exit pupil so I mostly observed at 60x for 6.7 exit pupil. Next time I’ll try my 40mm for a supersized exit pupil as suggested by Jon Isaacs on CN and will try my 25, 18 and 15 just in case.

This literally made my night as I hadn’t seen it before.

[mental4astro (Alexander)]

Matt,

Congrats on your first view of the Horsehead!

With your 16" & under Bortel 3/4 skies, the Horsehead should be visible without needing a filter. The Horsehead's reputation as being a difficult object is way over rated as being able to see it is far more a measure of the quality of transparency and the lack of people being able to recognise good transparency vs everything else. That it can be seen in a 4" aperture speaks volumes to this being the case.

From my Club's Bortle 4 site & my 17.5" dob, I have had nights when seeing the dark pillar was very easy with no filter & with amazing detail with a filter. I also had nights when it took all my experience & using filters to make out a featureless blob. And i also had nights when it remained totally invisible no matter what I did. Same site, same scope, different qualities of transparency.

What is surprising about this dark pillar is how large it really is. Far larger than the dark pillars just below Trumpler 14 in Eta Carina, but of course far less stark.

Being able to see the Flame neb is not good enough to determine if transparency is good enough - it is way too bright by comparison. Instead I use the Horsehead itself to tell me exactly how good transparency is. I use the Flame as a landmark, sure, but not much else. And I use the Horsehead's visibility from then on to sort out my final set of targets exactly because I now know just how good transparency really is. Not much use trying to spy out angle's-breath galaxy arms when conditions are not up to it. And it isn't just the Horsehead that I use to determine transparency, but a swathe of celestial features both telescopic & naked eye. No matter how dark the sky may be, if transparency isn't up to scratch you will only be setting yourself up for a night of frustration if you don't recognise this most fundamental aspect of amateur astronomy. And no bit of kit will tell you this either. Your own eyes are best.

The take from all of this is to encourage you to come to recognise transparency conditions. Work out which nights are best for the really faint stuff and nights for objects that are better suited to less than perfect. Chase down the Horsehead more times & learn what the sky is telling you by then looking away from the eyepiece & up at the sky itself and what you can now see of naked eye DSO's. You will be surprised at the differences once you recognise good over everything else.

Alex.

[Matthieu (Matt)]

Thanks Alex, I very much appreciate you sharing what you’ve learnt over the years.

I only became aware of transparency after reading some of your comments about the homonculus in carina. I’m getting better at gauging it based on what I can observe. It’s really interesting how objects that were difficult when I first got the dob are becoming much easier. I think I’m still in the initial phase of quick learning where observations skills progress fast. It’s been very satisfying ��

Also I finely got to the point where I can reliably collimate the scope to good enough (still some light flaring though) but will confirm that at the Gipssland star party in March. So I can now focus a bit more on my observations skills.

Thanks again

PS: sounds like I should spend some time with Trumpler 14 too

[EpickCrom (Joe)]

Originally Posted by Matthieu

I had a great time last night with the Horsehead Nebula.

As I was panning through Orion without filter in my bortle 3 or 4 skies around midnight, I noticed that the Flame Nebula was visible with direct vision in my 16”. I took that as a sign to try for IC 434 and the Horsehead.

I screwed on my new to me H-Beta filter and lo and behold could immediately see the gaseous cloud. I now understand why others have referred to it as a dagger.

Spending a bit more time with averted vision, a black notch perpendicular to the dagger and going about half through became very apparent. I took note of closest stars and validated in Interstellarum at the scope and Stellarium once I got back inside.

I had some focusing issues with 1.25” eyepieces so only used my 30mm for 60x and 12.5mm for 144x). 144x was too dim with a 2.8 exit pupil so I mostly observed at 60x for 6.7 exit pupil. Next time I’ll try my 40mm for a supersized exit pupil as suggested by Jon Isaacs on CN and will try my 25, 18 and 15 just in case.

This literally made my night as I hadn’t seen it before.

Hi Matt.

Congratulations on nabbing the Horsehead! Must have been awesome to see it with your own eyes. I'm yet to attempt an observation of it, My backyard is way too light polluted to even see the Flame. I will try for it on my next dark sky trip.

You are very lucky indeed to have such a nice dark and transparent sky from home

Keep Observing
Joe