Wild Duck

[TrevorW]

http://www.flickr.com/photos/mylotia...2466/lightbox/


Target: Messier 11 in Scutum (Wild Duck Cluster NGC6705)
Camera: QHY 8 OSC
Scope: GSO CF RC200
EFR: f/8
Mount: EQ6 Pro
Exposures: 1hr 5 x 6min and 3 x 10 min captured 8/10/2010 between 9:30 and 10:30pm
Seeing: No moon, no wind, warm night average seeing
Guiding: Orion Starshoot Autoguider using PHD with ED80
Focus: Focus Bahtinov mask
Stacking: DSS no darks and flats
Processing: PS CS3

Right Ascension 18 : 51.1 (h:m)
Declination -06 : 16 (deg:m)
Distance 6.0 (kly)
Visual Brightness 6.3 (mag)
Apparent Dimension 14.0 (arc min)
Discovered 1681 by Gottfried Kirch.
Messier 11 (M11, NGC 6705) is "One of the richest and most compact of the galactic (open) clusters," to say it with Robert Burnham, Jr. M11 contains an estimated 2900 stars, about 500 of which are brighter than mag 14. An observer at the center of M11 would see several hundred first magnitude stars! So rich and dense, it was classified by Trumpler as II,2,r (some newer classifications have it as I,2,r).
The apparent diameter is given with discordant values; E.E. Barnard estimated 35', while the Sky Catalog 2000 gives 14'.
The age of the Wild Duck cluster has been estimated to amount 220 million years, as its brightest and hottest main sequence stars are of spectral type B8 (according to the Sky Atlas 2000), but also double that value (Burnham gives 500 million years). The higher value is supported by the fact that this cluster also contains many yellow and red giants of absolute magnitude around -1.0. G. Meynet's Geneva Team has recently calculated its age at 250 million years. It is receding at 22 km/sec.
M11 was discovered by the German astronomer Gottfried Kirch of the Berlin observatory in 1681. It was apparently first resolved into stars by William Derham about 1733. Charles Messier included it in his catalog on May 30, 1764.

[multiweb (Marc)]

Cool shot Trev - nice field and star colors.

[TrevorW]

Thanks Marc, it seems I"m getting a predominance of blue with the QHY8 OSC Marc, so I cut back on blue saturation a bit on this one.

Ara is more SW than Scutum which is more NW for me. Anything NW to NE is the part of the sky most affected by LP in Perth.

East to SouthW are the best areas for me too capture images but again I'm restricted by the roofline of my house Sth and SW.

[desler]

Crisp Trevor, nicely done!


Darren

[mill (Martin)]

Nice star colors Trevor, those shorter exposures make all the difference in the star colors

[TrevorW]

[QUOTE=desler;643872]Crisp Trevor, nicely done!


Thanks Darren

[TrevorW]

Originally Posted by mill

Nice star colors Trevor, those shorter exposures make all the difference in the star colors

Thanks Marty, Someone else mentioned to me just today about the longer subs and got me thinking whether much is gained by running 10 or 15 minute subs in LP suburban skies.

It may be me, but I think the longer subs induce more gradient which strips colour and some detail when you try and remove it using a PS plug in.

[mill (Martin)]

Longer exposures can be done with the right LP filter.
With these filters you can get just that bit more detail from objects.
With clusters it works different, the longer exposures will over saturate the stars so they will become white.
Shorter exposures will give nice star colors.
This hobby is full of traps and trial and error

[Hagar (Doug)]

Lovely star colours Trevor but I can't help thinking you may have missed the focus a little.

[TrevorW]

Hey you guessed it Doug I didn't refocus between targets like I should