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Pages: 1 Astrodj sage Reged: 08/24/11 Loc: Missouri Mu Her       #5268234 - 06/12/12 03:00 PM Edit   Reply   Quote Quick Reply   Anyone observed Mu Herculis lately? It is well placed for an attempt to split the B/C components right now. The A/BC pair is easy at 30+", Mags 3.4 and 10, and a pretty double for starters. The B/C pair however should be pretty challenging at about 1"? separation, Mags 10 and 11. I never tried for this one yet so I will be curious to see if I can do it. Seeing is a problem for my locale. Anyone had any luck with B/C? What aperture and magnification were used? Any estimate on the separation? Thanks, and steady skies! Post Extras:       VanJan sage Reged: 07/09/08 Re: Mu Her [Re: Astrodj]       #5273899 - 06/16/12 03:00 AM Edit   Reply   Quote Quick Reply   Observed this star early this morning with my 90mm F/10 refractor. With the BC pair at 1.0", 256d P.A. (2012), I had no hope of resolving it with this instrument. At 100X, the A-BC pair was reddish-yellow, pale blue. At 230X, the secondary looked "fuzzy", but nothing so focused as to provide even a guess at the P.A. My new pet name for the Mu Herculis system is "L-squared". In a low-power field, look slightly N and NW of Mu, and the reason for my pet appellation will be apparent. Best of luck and steady skies for the BC split. Post Extras:       C_Moon Pooh-Bah Reged: 10/23/09 Loc: Virginia Re: Mu Her [Re: VanJan]       #5274538 - 06/16/12 04:00 PM Edit   Reply   Quote Quick Reply   This one has been frustrating me lately as well, even with an 8". The glow of the bright A component adds to the difficulty. The B/C pair appeared fuzzy to me as well, but I have not yet got that satisfying view of separated components. I'm looking forward to a night of good seeing when I can crank up the mag! Post Extras:       RAKing Postmaster Reged: 12/28/07 Loc: West of the D.C. Nebula Re: Mu Her [Re: Astrodj]       #5278371 - 06/19/12 07:56 AM Edit   Reply   Quote Quick Reply   I try for Mu Herc every year, with a variety of scopes and have never split B-C. We have a lot of humidity along with the overhead Jet stream here in Northern Virginia, so it's a rare night when I get steady seeing in the summer. Still I try................ Maybe this year will be the one. Hope springs eternal... and all that. Ron Post Extras:       Astrodj sage Reged: 08/24/11 Loc: Missouri Re: Mu Her [Re: RAKing]       #5278661 - 06/19/12 11:31 AM Edit   Reply   Quote Quick Reply   Well, I gave it a shot last night with my XT10. Transparency was great. I could make out all 7 stars in Corona Borealis from my red/white zone. Usually I get only 6 on a good night. Seeing was good to very good, Porrima was a steady split at 150x. Mu Her was still a few hours from zenith when I first turned to it. I was still at 150x at this point, which I knew wouldn't be enough but I wanted to see how it looked at that magnification first. The red dwarf pair looked like a single star, but sharp. I had hope. The glare from the primary was going to be a problem though, even 30" away. I was using a 20mm Ultrascopic with a TV 2.5x Barlow for 150x. I switched to a 6mm orthostar for a 200X view. Not much of a field of view in that old eyepiece with a manual dob so I had to look and focus quick, over and over. No double, try as I might. Next I popped in a 4mm Nihon Sieko ortho for a look at 300x. No way this was going to work, the seeing wasn't good enough to achieve sharp focus for one thing. The field of view was so tight I spent more time adjusting the scope than viewing. Try again later, I decided, when it is closer to it's zenith. So I hopped around looking at some favorites for a while, then at around midnight I tried again. The widest apparent field eyepiece I own is a Meade 4000 13.8mm SWA. With the TV Barlow I get 217X with the dob, and the longest viewing time before re-centering, so I tried that. I got mixed results. At first there was just one faint companion. After a few minutes I began to notice what seemed to be the C star, amazingly close to the B star, popping in and out, a little fainter than the other. The 3rd, fainter star seemed to be almost (but not quite) in a straight line with the A/B wide pair. I do not know if this is in fact the orientation of B/C in reference to A or not. I was able to observe this for about 30 minutes with the apparent 3rd star popping in and out. I say "apparent", because it was only visible about 20% of the time. When both B and C were visible, I thought I could see both stars split with a hair of dark space between, with direct vision even. So...I think I got this one, but I've been wrong before. Anyone know the current P.A. of these 3 stars? Post Extras:       Astrodj sage Reged: 08/24/11 Loc: Missouri Re: Mu Her [Re: Astrodj]       #5278678 - 06/19/12 11:39 AM Edit   Reply   Quote Quick Reply   Oh wow, I just noticed VanJan's post included the PA of b/c. Sorry, it has been a few days since I read your post. Thanks! I forgot to look at it with low power!! Post Extras:       Astrodj sage Reged: 08/24/11 Loc: Missouri Re: Mu Her [Re: Astrodj]       #5279578 - 06/19/12 08:38 PM Edit   Reply   Quote Quick Reply   I just looked up the WDS data for A/B and B/C. Most recent data is 2010. P.A. for A/B was 240d in 1781, 249d in 2010. P.A. for B/C was 245d in 2010. VanJan above says 256d in 2012. With a 43 year period an 11 degree position angle change in two years sounds reasonable. If all that is correct, I think I did split it as my observations seem to match the data pretty well. It turns out the A/B, B/C pairs are almost in a straight line, although the B/C "line" is pretty short! Post Extras:       VanJan sage Reged: 07/09/08 Re: Mu Her [Re: Astrodj]       #5280030 - 06/20/12 01:53 AM Edit   Reply   Quote Quick Reply   Post Extras:       David Knisely Postmaster Reged: 04/19/04 Loc: southeastern Nebraska Re: Mu Her [Re: Astrodj]       #5283284 - 06/22/12 03:46 AM Edit   Reply   Quote Quick Reply   Quote: Anyone observed Mu Herculis lately? It is well placed for an attempt to split the B/C components right now. The A/BC pair is easy at 30+", Mags 3.4 and 10, and a pretty double for starters. The B/C pair however should be pretty challenging at about 1"? separation, Mags 10 and 11. I never tried for this one yet so I will be curious to see if I can do it. Seeing is a problem for my locale. Anyone had any luck with B/C? What aperture and magnification were used? Any estimate on the separation? Thanks, and steady skies! I tried it in my 14 inch f/4.6 Newtonian a couple of nights ago, but the winds made high power observations difficult. The A and B pair were very easy and widely separated (about 1" arc seeing or maybe a little better), but even at 384x, I could not clearly detect much in the way of duplicity in the B component. It was weakly reddish in color and showed a diffraction disk at times, but other than maybe hints of an elongation, I didn't see the C component. I may try this one again later, but for now, I guess I still haven't seen Mu-C. Clear skies to you. Post Extras:       David Knisely Postmaster Reged: 04/19/04 Loc: southeastern Nebraska Re: Mu Her [Re: David Knisely]       #5316993 - 07/14/12 04:31 AM Edit   Reply   Quote Quick Reply   I got the C component tonight at 384x in my 14 inch f/4.6 Newtonian. It was sitting just outside the B component's first diffraction ring, so the separation seems to be slightly smaller than an arc second. In addition, the C component is definitely fainter than the B component, making C much harder to see. It was also on the side of the B component that was away from the A component. Clear skies to you. Post Extras:       Astrodj sage Reged: 08/24/11 Loc: Missouri Re: Mu Her [Re: David Knisely]       #5319698 - 07/16/12 12:49 AM Edit   Reply   Quote Quick Reply   Quote: In addition, the C component is definitely fainter than the B component, making C much harder to see. It was also on the side of the B component that was away from the A component. David, this correlates with what I observed. I am somewhat suspect that I was able to split it at 217x in a 10". But, I did have a keen eyed youngster who also saw what I saw and described it without my prompting. And your description fits well with what I saw. The C star was just a tad off of being in a straight line, and opposite from the A star. I will have to repeat this to be satisfied that I really did it though.. Congrats on your split though! Post Extras:       Cotts Just Wondering Reged: 10/10/05 Loc: Toronto, Ontario Re: Mu Her [Re: Astrodj]       #5320624 - 07/16/12 03:41 PM Edit   Reply   Quote Quick Reply   I will be taking a look at this challenging system this week while I'm at the David Levy Adirondack Astronomy Retreat. I will use my 16" and, just for the heck of it, I'll put 400x on the 6" AP too. Dave Post Extras:       Cotts Just Wondering Reged: 10/10/05 Loc: Toronto, Ontario Re: Mu Her [Re: Cotts]       #5324776 - 07/19/12 10:46 AM Edit   Reply   Quote Quick Reply   I got a difficult but clean split of this in my 16" @ 400x. The BC pair have a separation of 0.994" and a PA of 256.0 this year (6th Catalog of Orbits, WDS). Since the PA of the A-BC pair is 249 the three stars would appear to be in a virtually straight line as stated upthread. I saw them this way in moments of good seeing. Interesting info from the 6th catalog of orbits - you'd better split this one soon as it is closing rapidly. Here are the ephemerides for the BC pair currently showing: Year.....PA..............Sep..... 2011....250.2.........1.065" 2012....256.0.........0.994" 2013....262.8.........0.900" 2014....271.4.........0.794" 2015....282.6.........0.687" Interesting fact #2. The 'Discoverer Code" for the BC pair is " AC 7 ". The discoverer of this pair turns out to be none other than Alvan Clark, the legendary lens-man!!! Dave Post Extras:       Astrodj sage Reged: 08/24/11 Loc: Missouri Re: Mu Her [Re: Cotts]       #5328682 - 07/21/12 06:30 PM Edit   Reply   Quote Quick Reply   Quote: I got a difficult but clean split of this in my 16" @ 400x. The BC pair have a separation of 0.994" and a PA of 256.0 this year (6th Catalog of Orbits, WDS). Since the PA of the A-BC pair is 249 the three stars would appear to be in a virtually straight line as stated upthread. I saw them this way in moments of good seeing. Interesting info from the 6th catalog of orbits - you'd better split this one soon as it is closing rapidly. Here are the ephemerides for the BC pair currently showing: Year.....PA..............Sep..... 2011....250.2.........1.065" 2012....256.0.........0.994" 2013....262.8.........0.900" 2014....271.4.........0.794" 2015....282.6.........0.687" Interesting fact #2. The 'Discoverer Code" for the BC pair is " AC 7 ". The discoverer of this pair turns out to be none other than Alvan Clark, the legendary lens-man!!! Dave Nicely done! Thanks for the 6th catalog data, it is indeed closing up quickly. And I did not know Alvin Clark was the discoverer. Very interesting. Did you really try the 6" AP? For the record, I repeated my earlier observation in the XT10 with a split of this double last night. I was able to see a clean split at 217x, and at 300x. It was much easier to see the split at 217x than it was at 300x. The moments of better seeing were too fleeting at the higher magnification. But, at 217x it was a pretty sharp view and I did not have trouble seeing it. Before trying this double, I would have bet money it would need at least 300x to see a clean split, and therefore I was skeptical of having done it at 217x. But I have no doubts now. I know I got this one. Post Extras:       dpwoos Pooh-Bah Reged: 10/18/06 Re: Mu Her [Re: Astrodj]       #5330732 - 07/23/12 01:21 AM Edit   Reply   Quote Quick Reply   Here in Vermont, our (homemade) 10" f/6 has no problem splitting mu at 250x (TMB 6mm Planetary does the job nicely), and at 312x they are well separated (4.8mm Nagler). I really enjoy this target, and have shown it to a lot of folks in our club. Even in mediocre seeing it is not too hard to detect the B-C orientation (a number of club members have been able to do this), though a clean split requires at least good seeing. I think the reason why it is not as difficult as one might think is that B-C are nearly the same magnitude. Post Extras:       Pages: 1

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