The Horsehead Challenge for 2015/16

[estwing]

Clarkpm4242..the mob was on the verge of going last month but we pulled because of the forecast

[Mr Flibble]

This was my number one target for last winter but I failed. I've worked out the exact location and I use a 25mm tv plossl and Hb filter but its not happened yet.

I assume that not only is a dark sky needed but also good transparency as well. Seems to be the case with these really faint nebulae.

[scarp15]

This was my number one target for last winter but I failed. I've worked out the exact location and I use a 25mm tv plossl and Hb filter but its not happened yet.

I assume that not only is a dark sky needed but also good transparency as well. Seems to be the case with these really faint nebulae.

Probably best to tackle it after you have hit on a few other faint and challenging objects, gaining full dark adaption and visual responses are finely tuned. 

[John]

Probably best to tackle it after you have hit on a few other faint and challenging objects, gaining full dark adaption and visual responses are finely tuned. 

This seems good advice to me. I've noticed that my visual accuity for detecting faint objects improves during the course of a decent session on such objects. After a while I seem to be very sensitive to any sort of light that might dent my dark adaptation. Even a dim red torch or illuminated reticule finder seems glaring when I've got myself "in the zone" as it were.

[mikeDnight]

I've never seen the horse head though I once managed to see the flame nebula through my FS128 but it took a lot of effort, possibly because of the bright field star. The site and night were not particularly good, however the horse head was not visible to me at that time.

Now though I have a secret weapon - a black blanket - that surrounds my head and eyepiece, shielding me from any stray light and enabling complete dark adaption. Although the scope I now use is of a smaller aperture, it is hellish good, and I've seen some fantastic sights through it. With persistence and patience and my black blanket im going to give the horse head another go this winter. I just need a transparent moonless night.

Mike

[John]

Thanks for that tip Mike

I have tried observing under a dark cloth (a towel actually) and it does help. 

[Moonshane]

I think I might have to try this myself. Neighbour insecurity lights are becoming a pest.

[cuivenion]

I think I might have to try this myself. Neighbour insecurity lights are becoming a pest.

That's why I'm trying out goto and video astro, half the stars in the sky disappear when the floodlight comes on. Going to have to get to a dark site again sometime soon when the skies clear.

[YKSE]

Just did some check

The size of HH is 8'x4', this happens to be size of M1! Having a look at M1 with HH eyepice first might be of some help for looking for right size.

[John]

Just did some check

The size of HH is 8'x4', this happens to be size of M1! Having a look at M1 with HH eyepice first might be of some help for looking for right size.

Interesting. I thought the HH would be larger than I was expecting so some visits to M1 will be part of the preparation

[Dave In Vermont]

I think I'll start a new challange at some point: Photographically record the HH with the most rudimentary and ill-suited jumble of equipment possible!

I'd be willing to bet that the results will surprise (and possibly shock) people.

I'm not kidding -

Dave

[John]

I'm fairly sure that the HH can be imaged pretty easily. Not in great detail (which is somewhat more difficult) but at least recognisably as a dark notch against IC 434.

It's seeing it with my eyes that I'm interested in.

[alan potts]

I will be joining you in that quest with a large tool which I feel will do the job but once that is done I may well try it with the 12 inch. As I said the other day I also want to try for Trapizium G and H which I am sure will be just as difficult.

I feel if anything lets you down it will be the sky condition you have, it will not equipment or lack of effort from you.

Alan

[bish]

I may give it a go - but it would mean investing in another filter.  I have seen it through a good 10" scope (with H-beta filter) from Kielder , but couldn't see the horse shape, just a notch.  The flame is fairly easy on a good night from my parent's garden (10" with UHC), so I may try it from there with my 10".  It's a shame that the H-Beta is a bit limited in it's use as I need to justify buying one (or do I ??).

[estwing]

Don't think you need a filter for this...its transparency and dark skies but the HB is going to help a heck of a lot

[bish]

Don't think you need a filter for this...its transparency and dark skies but the HB is going to help a heck of a lot

I'll try without the filter then. I have a UHC which may help. It would be good to have a go without having to buy extra kit.  I think because the HB seems to always get mentioned with the HH I assumed it was a must have for the HH. Just have to wait for the weather to now!

[Paul73]

There are lots of reports of viewing the HH with a UHC. I'm guessing that this is like a really really faint version of the Veil. The UHC moves it from the invisible to the visible. But, with a decent OIII.....

Paul

[John]

I really like Jeremy Perez's description of observing the Horsehead:

"....it's like trying to see a little bit of nothing with a little bit of less than nothing resting over it....."

[YKSE]

There are lots of reports of viewing the HH with a UHC. I'm guessing that this is like a really really faint version of the Veil. The UHC moves it from the invisible to the visible. But, with a decent OIII.....

Paul

My way of understanding how thess filters work is by looking at their characteristics.

The main light spectrums for these filters are 486nm (H-beta), 496nm(OIII) and 501nm(OIII).

Hb filter: high transmission for 486nm, blocks the OIII lines(496nm and 501nm) totally.

OIII filter: high transmission for OIII lines, blocks the 486nm totally

UHC filter: high transmission for all H-beta and OIII lines, blocks spectrums outside these area.

The logical consequence of this is

1. Nebulas with strong light spectrum in 486nm, will benefit most with Hb filter, UHC works too with lesser contrast, while OIII will totally kill the nebulas, HH and Cocoon are examples.

2. Nebulas with strong light spectrums in 496nm and 501nm, will benefit most with OIII filter, UHC works too with lesser contrast, while Hb will totally kill the nebulas. The Veil is a good example.

3. Nebulas with strong light spectrums in both H-beta and OIII lines, UHC will show most extended nebulosity, while OIII and Hb will show very different partial nebulosity.

4. Nebulas without strong light spectrums in these area, none of these filters can be of any help.

[Stu]

More interesting stuff here, apologies if this has been posted before.

http://freescruz.com/~4cygni/haggisizing/astro/HH-sense.htm

[swamp thing]

Good luck to all hunting the nags head this year.

My tip:

I found the close double at the back of the horses neck of highest importance when locating it. These two stars make a positive point from where the back of the neck  starts.

Have fun

[Stu]

Is there any particular level of sky brightness above which its not worth trying?

[Mark at Beaufort]

I found the close double at the back of the horses neck of highest importance when locating it. These two stars make a positive point from where the back of the neck  starts.

Have fun

Steve I agree. If you draw a line from Alnitak through the 7.5 mag star SAO 132451 to a 10.9 star which is 14' away - this star is almost on the back  of the Neck of HH

[Stu]

This?

[John]

All very interesting ....... still blooming cloudy though

I got a glimpse of Orion briefly through a gap in the clouds lat last night. I guess that lasted around 30 seconds !