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The Mekon
20-09-2017, 05:03 PM
Last night I turned my new CFF 132mm to NGC 6193 in Ara.

The brightest star in this cluster/nebulosity is H 4876 and 21 years ago I noted this a close double with a 9th mag companion. I was using my Astro-Physics F8 130EDT at the time and the conditions must have been pretty good for me to observe this companion as the separation is around 1.5" and there is a 3 mag difference between primary and secondary. Despite a number of attempts to split this system again, I had failed to do so and was wondering if I had fudged the observation 21 years ago.
Last night I set the CFF to NGC 6193 and with a magnification of 183x clearly split the major star in this group, doubling up with a barlow to check and it was even better! This star has two other companions one about 10" west and another 13" SE. The hard part is observing the close companion to the North.

Would appreciate any other reports

John

Tinderboxsky
21-09-2017, 02:23 PM
Interesting tale with a satisfying outcome.
I do not have a record for this in my log, so I’ll add it to my target list. I will have to be patient waiting for the right night!

The Mekon
21-09-2017, 07:15 PM
Thanks Steve, I am disappointed there is not more action in the observing section of IIS. Too many equipment junkies!

On a following note, nearby to NGC 6193 is what I consider perhaps the best triple double in the sky - it is not easy to view, but not hard to find. This is a topic for another thread though.

Tinderboxsky
22-09-2017, 11:48 AM
Yes, it is disappointing there is not more observing activity posted. I guess I am guilty of this too as I only post a very small fraction of my observations. I am a keen and active visual observer interested in a broad cross section of targets and observable events. I have a particular interest in observable transient events but only manage to see just under 50% of the events I am interested in - the events are time specific and the clouds are blissfully unaware of my needs. then, time gets away from me and I wonder who would be interested any way. Interest in the night sky these days is dominated by astro imaging and as you say there are alway plenty of equipment junkies in the back ground.

By the way, your reference to H 4876 has me slightly confused. I browsed Sky Safari last night to find the double star and it’s position within NGC 6193 to give me a feel for the target and the surrounding star field. Sky Safari lists the brightest star in NGC 6193 as HR6187 and does not give H 4876 as an alternative catalogue number. Visual magnitudes are listed at 5.57 and 8.39 with a separation of 1.7” at 9.0 degree. So It would have to be the same double star. I have not had a chance to reference other charts.

Do post about your nearby favourite triple when you have a free moment!

The Mekon
24-09-2017, 05:36 PM
Thanks for checking on this Steve.

You are correct in that the star in NGC 6193 is also listed as HR 6187. Not sure but this may be one designation for the whole system.
My reference to H 4876 comes originally from Burnhams which I used on the original observation 21 years ago. In fact I now use
http://stelledoppie.goaction.it/index2.php?section=1 to check out doubles and looked it up under this number (4876) and it came up with the 6193 system, particularly labelling AD and AE components under this designation. I did not see the D component with the 132mm, but can see it easily with the 18", but then again this scope does not show the close B component!

All up this is a delightful system to study, with three stars around 10" or less separation from the primary, + the close component at 1.7"

John

bigjoe
24-01-2018, 10:14 PM
Missed your report John..
Theres hardly any references to this multiple star in N6193... h 4876..I need to check it out early morn ..as soon as I have some seeing here in Sydney..do a report....and in the same sized triplet Apo too.

bigjoe.

The Mekon
25-01-2018, 05:52 PM
Joe, yes you will have to rise early to get this one. I would advise waiting till later in the year. From May onwards will be a good time. I will counsel you to be patient with your new Apo. Some nights you may think "what is wrong with my scope" - it is invariably the seeing. Get the right night and the magic will happen as it can with a fine Apo refractor. You will find the secret is that in these conditions you do not need huge magnifications for the scope to work.

bigjoe
25-01-2018, 07:20 PM
.

I know what your saying John..
Indeed these can even take some time to cool down....and good seeing is where these shine.

Like you I have other scopes as well on standby ..may even get another Apochromat about 90mm in next 6 months as a grab and go..

bigjoe.

Tropo-Bob
26-01-2018, 08:52 AM
John, NGC 6193 is on of my favourite clusters and unfortunately has never rated a mention till now.

I am also curious to know more about the triple that U have mentioned.

bigjoe
26-01-2018, 03:15 PM
.
Myself also..

Sounds like as John mentioned ..we may have to wait for a few months , or get up early to observe..I myself cant wait for a crack at it among others...thats if the weather clears.

bigjoe

The Mekon
27-01-2018, 09:24 AM
Bigjoe, Bob, Thanks for the replies. I am going to post a separate thread on this "triple double" in the Observational and Visual section of this topic heading. See you there!