Observing report 18-02-06 (brief)

My first attempt at posting this landed in uk.sci.weather, so here's
hopeing I get it right this time...


It's been quite a while since I last used a telescope - in fact I think it
was October. My interest tends to wax and wane. That and health/weather/
life getting in the way, has prevented me from observing.

However, the sky was gloriously clear on Saturday evening, the Moon
wasn't a problem and I was healthy and at home.

So, I got Mini Hubble (my Europa 250) out of mothballs and into the
garden. I'd charged the batteries for the mount earlier and, while not
fully charged, they'd do.

I wasn't going for the long haul this time, just a refresher to get
my feet wet again. Started out with M42 of course. In the 32mm e/p (x37.5)
it was a glorious sight. The four main components of the trapezium were
evident, if a little on the small side. Bumped the e/p to a 20mm (x60)
and this gave the best view. The nebula filled the field nicely. Tried
adding a UHC filter but I felt it didn't add much to the view so removed it
again.

I left the 20mm in but re-added the UHC and aimed myself at zeta to see if
I could detect the Flame Nebula. Nope. Tried averted vision, eyes closed
for a period, the usual tricks but I just can't make it out.

Feeling slightly despondant I aimed at M45, but bumped it back down to the
32mm+UHC. The Pleiades are a lovely sight but I just can't make out any
of the nebulosity. It's probably more to do with my mag 4.5 skies than
of the nebulosity. It's probably more to do with my mag 4.5 skies than
any defects on the part of the optics, but even so it was disappointing.
In truth though I've tried and failed on this before, so my hopes weren't
high. M45 remains a lovely sight though.

Decided to give Saturn a whirl. Got her centered in the 32mm, then upped
to my favourite planetary viewing combination - a 20mm coupled to a Televue
x5 Powermate. This gives me a magnification of x300 but leaves me with the
good eye relief of the 20mm.

My view of Saturn was probably the best I've ever had, bar none. It
justified my outside excursion totally. The Cassini Division, normally
somthing I have to struggle to see, was etched like a line of blackest ink
on the rings. Many bands were visible on the planet itself, the shadow of
the planet on the rings was visible, the darker band of the inner ring as it
crossed the planet...it was all there for me to see. I spent about 30 mins
just staring at this sight. Couldn't see the Encke gap but then I wasn't
really trying to.

Having drunk my fill of Saturn (and promising myself to return at the
earliest moment possible) I decided to end the evening with NGC 2392.
This is the Eskimo Nebula, a planetary in Gemini. The first time I tried
to find it it took me an hour. That was two years ago and I hadn't been
back since, so I thought it would be interesting to see how long it
took me this time.

5 minutes.

The combination of knowing roughly where it was, coupled with my knowledge
of what I did wrong the first time (didn't use enough magnification) and,
let's be honest, luck, all played in my favour. A 2x barlowed 20mm ep
gave me the best view.

One thing I've noticed (just as an aside) is that despite the fact that
I have a fairly good range of e/ps (4, 6, 10, 15, 20, 25 and 32 mm) I
tend to fall back on the 32mm and 20mm for my general viewing. Sometimes
I couple them to either a x2 or x5 adaptor. This is simply due to the
fact that the 20mm is a good e/p (even though it's a no-name Plossl)
and the eye relief is good.

Sorry for this rambling and rather unproffessional report.

Jim
--
Find me at http://www.ursaMinorBeta.co.uk
JediGeeks http://www.jedigeeks.com
"Ah, gentle dames, it gars me greet, To think how monie councels sweet,
How monie lengthen'd, sage advices, The Husband frae the wife despises!"

Hi Jim,

Nice report. We were out with the York AS at Sutton Bank on Saturday night
and indeed the sky was fantastic with stunning views of Saturn on show for
the hundreds of people who turned out. We had non stop queues at all our 8
or 9 telescopes from just after 6pm until gone 9pm.

One thing you mentioned Jim about looking for the nebulosity around M45.
Don't use your UHC filter for this because the nebulosity there is a
reflection nebula so the UHC filter will block most of it out.

UHC filters are designed to only let the narrow emission lines of Hydrogen
and Oxygen through, so they really make a huge difference on emission nebula
where most of the light in in these narrow wavelengths. Objects such as
M42, M27, M57, the Flame Nebula, the Eskimo nebula, etc are greatly enhanced
using these filters due to the big increase in contrast you get with a UHC
filter. With the reflection nebula around M45, or M78 for example, you want
a full spectrum, so a narrow band filter such as a UHC or OIII filter is not
useful and will not help.

To be honest I've only been able to visually see the M45 nebulosity once,
and that was under the very dark skies of Kielder Forest in Northumberland,
at one of the Kielder Star Camps, using someone's very nice, long focal
length 5" refractor. The nebulosity around Merope was visible, with hints
around one other star. I've never seen it again depite trying many times
with my own 250mm F4.8 scope, so I've come to the conclusion that very, very
dark skies are essential to observe this nebulosity visually.

Hope you are suitable inspired after Saturday night to get your scope out
more in the future.


Very best wishes and clear, dark skies.


--

Paul B, York, UK.

York Astronomical Society
www.yorkastro.co.uk
Please buy from the YAS web shop and help YAS raise funds





"Jim" wrote in message
...
My first attempt at posting this landed in uk.sci.weather, so here's
hopeing I get it right this time...


It's been quite a while since I last used a telescope - in fact I think it
was October. My interest tends to wax and wane. That and health/weather/
life getting in the way, has prevented me from observing.

However, the sky was gloriously clear on Saturday evening, the Moon
wasn't a problem and I was healthy and at home.

So, I got Mini Hubble (my Europa 250) out of mothballs and into the
garden. I'd charged the batteries for the mount earlier and, while not
fully charged, they'd do.

I wasn't going for the long haul this time, just a refresher to get
my feet wet again. Started out with M42 of course. In the 32mm e/p (x37.5)
it was a glorious sight. The four main components of the trapezium were
evident, if a little on the small side. Bumped the e/p to a 20mm (x60)
and this gave the best view. The nebula filled the field nicely. Tried
adding a UHC filter but I felt it didn't add much to the view so removed
it
again.

I left the 20mm in but re-added the UHC and aimed myself at zeta to see if
I could detect the Flame Nebula. Nope. Tried averted vision, eyes closed
for a period, the usual tricks but I just can't make it out.

Feeling slightly despondant I aimed at M45, but bumped it back down to the
32mm+UHC. The Pleiades are a lovely sight but I just can't make out any
of the nebulosity. It's probably more to do with my mag 4.5 skies than
of the nebulosity. It's probably more to do with my mag 4.5 skies than
any defects on the part of the optics, but even so it was disappointing.
In truth though I've tried and failed on this before, so my hopes weren't
high. M45 remains a lovely sight though.

Decided to give Saturn a whirl. Got her centered in the 32mm, then upped
to my favourite planetary viewing combination - a 20mm coupled to a
Televue
x5 Powermate. This gives me a magnification of x300 but leaves me with the
good eye relief of the 20mm.

My view of Saturn was probably the best I've ever had, bar none. It
justified my outside excursion totally. The Cassini Division, normally
somthing I have to struggle to see, was etched like a line of blackest ink
on the rings. Many bands were visible on the planet itself, the shadow of
the planet on the rings was visible, the darker band of the inner ring as
it
crossed the planet...it was all there for me to see. I spent about 30 mins
just staring at this sight. Couldn't see the Encke gap but then I wasn't
really trying to.

Having drunk my fill of Saturn (and promising myself to return at the
earliest moment possible) I decided to end the evening with NGC 2392.
This is the Eskimo Nebula, a planetary in Gemini. The first time I tried
to find it it took me an hour. That was two years ago and I hadn't been
back since, so I thought it would be interesting to see how long it
took me this time.

5 minutes.

The combination of knowing roughly where it was, coupled with my knowledge
of what I did wrong the first time (didn't use enough magnification) and,
let's be honest, luck, all played in my favour. A 2x barlowed 20mm ep
gave me the best view.

One thing I've noticed (just as an aside) is that despite the fact that
I have a fairly good range of e/ps (4, 6, 10, 15, 20, 25 and 32 mm) I
tend to fall back on the 32mm and 20mm for my general viewing. Sometimes
I couple them to either a x2 or x5 adaptor. This is simply due to the
fact that the 20mm is a good e/p (even though it's a no-name Plossl)
and the eye relief is good.

Sorry for this rambling and rather unproffessional report.

Jim
--
Find me at http://www.ursaMinorBeta.co.uk
JediGeeks http://www.jedigeeks.com
"Ah, gentle dames, it gars me greet, To think how monie councels sweet,
How monie lengthen'd, sage advices, The Husband frae the wife despises!"

In article , Paul Buglass wrote:

One thing you mentioned Jim about looking for the nebulosity around M45.
Don't use your UHC filter for this because the nebulosity there is a
reflection nebula so the UHC filter will block most of it out.

UHC filters are designed to only let the narrow emission lines of Hydrogen
and Oxygen through, so they really make a huge difference on emission nebula
where most of the light in in these narrow wavelengths. Objects such as
M42, M27, M57, the Flame Nebula, the Eskimo nebula, etc are greatly enhanced
using these filters due to the big increase in contrast you get with a UHC
filter. With the reflection nebula around M45, or M78 for example, you want
a full spectrum, so a narrow band filter such as a UHC or OIII filter is not
useful and will not help.

Ah! Thanks for that. I'll give it another go over the w/e (weather etc. allowing)

Mind you, from what you say then it's unlikely but, heck, you never know until
you try.

Very best wishes and clear, dark skies.

And to you.

Jim
--
Find me at http://www.ursaMinorBeta.co.uk
JediGeeks http://www.jedigeeks.com
"Ah, gentle dames, it gars me greet, To think how monie councels sweet,
How monie lengthen'd, sage advices, The Husband frae the wife despises!"