2MASX J16394598+4609058 in Sweden next week

[Hakann]

I will go for a star party in Sweden and the club there has a 60 cm ( 23.62” ) f/6 at 40 mm thick ( rather thin at ratio 15;1 ) made in France by Cardoen.
Sky can be pretty good and maybe at best around SQM-21.5, but as this time of year the moister is a issue.
But the telescope is in a dome way above ground, but sky will still probably has moister.
The area is not that great on the Bortle scale and nearby cities do pollute.
One of the galaxy's I’m after in Hercules is the 2MASX J16394598+4609058 I saw at OSP in Howards 28” ( or say I briefly saw it )
I will use Ethos EP and say 8 mm that give 450X and a 1.3 mm pupil.
-Will it be a chance to see this galaxy and Hercules is at a decent position now.
The telescope track good and mirror was new coated last year.

[Jimi Lowrey]

Good Luck Hank! FYI from the OGC Superluminous Spiral paper it gives a diameter of 134KPC for this galaxy.

[Hakann]

I will come back on it.

A question ;
What magX per inch do this faint dim galaxy’s that often debate here on DSF need in 'general' ?
To come to live at the best if decent or great steady sky and dark ( say LaPalma/Canariers high alt and near SQM-22 )
So far I know, ex 150X in a 10" is equal as 360X in a 24" vs brightness, but higher magnifications also take out some of the brightness that might be needed as well, or ?
( Timo from Sweden is in west Australia now and I read he use 150X on his 10" on faint dim galaxy's, and that is 15X/inch )

I ask ‘overall’, or in general off faint fuzzies observing, as I might plan a low obstruction 30” at f/4.
That scope require a ‘special’ focuser.
Here is the idea as Delos or Ethos 6/8 mm has the same design and Ethos 3.7/4.7 mm has the same design and will intrude some if using a 3.5” diagonal that get a a obstruction at 11%.

8.0 mm = 380X. (12X/inch )
6.0 mm = 507X. (17X/inch )
4.7 mm = 647X. (21X/inch )
3.7 mm = 822X. (27X/inch )

[Jimi Lowrey]

From my experience a 1.5 to 2mm exit pupil is best for faint fuzzes.

[Hakann]

Ok,
For that combo on pupil 1.5-2 mm ;

8.0 mm = 380X. (12X/inch ) = 2.0 mm pupil.
6.0 mm = 507X. (17X/inch ) = 1.5 mm pupil.

[Hakann]

The star party had its first night in rain, but night to Sunday after the moon went down it was pretty clear, but as this time of year is almost in moister so sky is seldom ok here.
My knowledge as a ‘former’ drag racer I knew only time is weather is ok is here ( spring or fall ) is when cold winds blowing from the north down south.
( summer here vs astronomy/deep-sky is cancelled at 62 degrees )

This 60 cm telescope is in a dome so moister did not grab the optics, but the guys outside it had to close down fast as a ‘dew festival’ ;-)
It was a hair over SQM-21 but sky had full of moister in it, but straight up it was pretty ok so we could observe for say 2-3 hours.
The dome is big inside but as a f/6 with a huge ladder and 5-10 people and get it to point ok ( go-to and tracking ) time goes fast and one will not see so many objects.
The 3 BLY galaxy was a close down affair direct here but we was in Abell 72, Superman galaxy etc.

I went to see a Pyrex 30" blank on the way back home, and it is a machined from Rigolato in Italy to f/4 and 40 mm edge so 34 kg and a 19;1 factor.
M-L Optic’s can do it and told me he had done several 22;1 at 36” before.
I asked a optician from Australia but he would not do this size at the 19;1 factor.
The Sweden polisher but can try, but he had do one before but edge was hard ( f/4 but 2” thick edge )

My idea here is a optic’s that can do the 15-20X per inch as if I shut for 1.5-2 mm pupil as a small obstruction ( 11% ) faint fuzzes ( only ) telescope at LaPalma by using the TV Delites EP less a coma corrector.
( Sweden is nothing for a ‘bigger’ telescope at all, and I would not use/get a cheap 10” Dob for this sky, at least not for the astronomy I like to do )