Star: Gamma Virginis, Porrima (Struve 1670)
Date & Time: 6 May 2002
10pm to midnight local
Seeing: 3 <1-10 Seeing Scale (10 best)>
Transparency: very good
Location of site:  Silverdale Wa. USA 47N, 123W
Site classification: Rural
Sky darkness: 5.7-6 <Limiting magnitude> 
Temperature: 30º F
Telescope: Celestron C8
Eyepieces: 
Magnification: 
Eyepiece: Videocamera PC164C, 3x barlow, 28 Pl
Magnification: equal to 333x, 1000x
 

 
Supplement to previous post on companions AE and AF, Actually managed to get them on a prime focus image, but just and not at the same time. Will post a composite picture of both. Component AF measures conciderable different from WDS data of 1909 but AE is close to the 1991 measure. Measurements: AE 258.7 sec, 169.8 deg PA, AF 
428.8 sec, 268.7 deg PA 

My sole purpose tonight was to see what the heck I could do with Porrima using an 80 mm refractor. At ~1" of arc separation, I knew my "success" would be limited due to the 3"ers resolution limit but having a double with such equal components(in magnitude) I figured if I could see any evidence of duplicity, it would reaffirm my belief that this scopes optics are top notch. I was not disappointed. ;^)

I found a definite elongation(so close to direct E-W)of the star using a 7.5mm Tak LE & 2.5x Powermate(213x) Just to double check the validity of this observation, I trained the scope on a couple of other stars, including Spica, and they appeared as perfect pinpoints so I'm convinced I saw what I saw. 

At this power, the yellowish colour(seen at lesser magnification) pretty much disappeared and the best I can describe it is as off white. I spent a good 40 minutes experimenting at different mags and found that, on this particular night, the 213x was optimum.

I know there are a lot of small aperture scope users in our group...I'd love to see how you fare.
 

I could not be certain of anything at either 150X (8mm)or 200X(12mm + barlow), so I barlowed the 8mm, but the seeing would not support the 300X for anything but very brief moments - not long enough to examine the star carefully. I then pulled out my 9mm and barlowed that for 266X. It was here I could see an elongation close to east/west  orientation, but more so, an ese/wnw slant. No color apparent and no hint of a figure-eight could be detected (I was actually surprised to get what I did).

 Prior to Bill's suggestion, I had not considered trying a 3" on this illusive, tight double. While no split was possible, it was enjoyable to at least get a glimpse of it's duplicity.
 

Note: I am afraid that my separation estimate of gamma Virginis is biased by the numerous reports already available, but anyhow it seems reasonable.
 
 
 
 
 
 
 
 

Different focuses doesn't help, so I decide to pump up to the 5mm (240x).  This did the trick.  My eyes were deceiving me at first, as now I had clearly found a double star.  Mostly notched, with fleeting glimpses of dark lane.  Approx PA of 60°.  If seeing were a bit better, this would've been no problem for the 8".  Comparing to my early view of Zeta Cancer (.6"), I would have to estimate that this was only slightly tougher, 
say about .5"  Rate this one a 2.

Ambience: This place is considerably quieter than my old home. Only the faint drone of traffic from a freeway 3/4 a mile away.  A loud rock band is playing at some party in the neighborhood.  Ducks on the pond nearby are making their night time "Qwaaaaa"
noises.  None of this is near as distracting as the old home with it's traffic, sirens, and police helicopters.  Many times more peaceful and relaxing.  Not one gunshot was heard.
 

Star: Gamma Virginis, Porrima (Struve 1670)
Date & Time: April 29th, 2002
00:00-02:00 JST (UTC+09:00)
Seeing: 8 <1-10 Seeing Scale (10 best)>
Location of site: Isahaya, Nagasaki, Japan
130º04' E  32º55' N)
Site classification: City(small) area
Sky darkness: Not dark for moon shine
Conditions: 16th Moon, Croudy, Clear in dawn
Temperature: not cold
Telescope: Celestron NexStar5
f/10 SCT(fl=1300mm)
Eyepieces: Pentax O-7, Celestron PL25
Magnification: 186x, 52x
 

1st diffraction disks are connected each other like binocular's view. And between the airy disks are very close like hair line.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

At 52x not split. Split at 186x.

Easier than two nights ago. It's very steady this night. So I thought it will be about 1.2 or 3 arcsecs in this time with my feeling. Next morning, I was so surprised to read about Porrima that it may be about 1.0 arcsecs! So I think I met the wonderful night by Mr.Hyakutake's favor from Heaven.  Next year, can I and NS5 split it? Trying is very fun!

Ambience: It was a whole cloudy night, but I wanted to attend the small star party at Shimabara for remembering Mr.Hyakutake, the famus Comet hunter, he was born
there and gone away April 17th in Kagoshima.

After some slide show and talking, some clouds began to go away. So we start to see Ikeya-Chang comet thinking about Mr.Hyakutake and his comets.
 
 
 

Star: Gamma Virginis, Porrima (Struve 1670)
Date & Time: Mon May 13, 2002, 23h to 01h UT 
Seeing: 7 <1-10 Seeing Scale (10 best)>
Transparency: 7 <1-10 Seeing Scale (10 best)>
Location of site: Göteborg, Sweden 
57°43' N, 11°58' E 
Site classification: Suburban area with moderate light pollution 
Sky darkness: 4-5 <Limiting magnitude>
Temperature: 10º-13º C 
Moon: None 
Telescope: Russian TAL-1 equatorial reflector 110mm f/7.3 
Eyepieces: 25mm and 12.5mm TAL Super Plossl, 15mm TAL Kellner, 3x TAL 
Barlow 
Magnification: 32x, 54x, 80x, 161x, 240x

Only an 8-shape detected at 161x and 193x.

I remember when I observed this star in the 70's, through a refractor in the observatory of my city. Then was a nice yellow pair.

Ambience: finally a clear night after so much time! The conditions aren't the best but well, I was so eager to explore Virgo. My observation place is close to the forest and I can hear the wind blowing between the trees. 

Now the nights become shorter and shorter, and the sky isn't really dark: it's the Nordic summer night. My observing session was reduced between midnight, and around three o'clock in the morning.
 
 
 
 
 
 

I just start to use a new eyepiece, a 10mm russian Plossl. It provides 80x in my scope, and 240x with the Barlow. At 240x, I confirmed the "8" shape, but not separation of AB components. On the other hand, components E and F which I overlooked before, are superwide and very easy at 32x, surely background stars.
 

9mm ortho(X133) -- I found a pale yellow star with a hint of elongation W-E. This was difficult to see at times but in moments of steady air I could see that this star was not perfectly round.

6mm ortho(X200) -- Confirmed the previous view, but this time a figure of 8 could be seen in odd moments of still air. The view was very unstable at times though.

6mm ortho with X2 barlow(X400)--I had to wait patiently in order to see a sliver of dark sky between the two components. The image was very unstable most of the time. 

6mm ortho with X2 barlow(X400) + apodising screen.-- This gave the best view!! Two distinct stars were seen for most of the time. A wonderful sight.

6mm ortho with X3.35 barlow(X670) + apodising screen.-- Amazingly, the sky supported this magnification, showing two distinct, if unstable images. I could observe both stars for most of the time.

CMG with X3.35 barlow( X322 ) + apodising screen-- I did not expect to get any good measure in PA as the two stars are too close to line up the scale properly. However, using Tom's drift method proved me wrong! An average of 7 transits gave a PA of 250degrees. Using the CMG gave the most pleasing view, with a tiny sliver of dark sky splitting this very close double star.

Ambience: After a nice sunny day, the evening settled into a calm and peaceful time. The telescope had been set up early to cool down ready for some early twilight observing. As the light gradually failed and the nesting birds had gone to roost, the tiny bats started their acrobatic displays.

The only sound was the alarm call of a blackbird disturbed by a cat or some other creature of the night perhaps. As the night progressed, heavy dew started to form on everything with the obvious problems to eyepieces etc.
 

There was no sign of duplicity @80x but definite elongation @145x. Moving up to 230x there was a clear figure of eight with occasional glimpses of
separation. This is normally pretty much the limit that seeing allows but
tonight 290x (13.8mm SWA + Barlow) revealed a clear split with only a slight degree of jumpiness. Barlowing the 12mm astrometric @340x was initially much more jumpy but stabilised after about five minutes to show a well defined dark lane between the two components. Higher magnification @460x still showed detail but at some loss of definition.

Both components appeared white with a faint yellow tinge. They were too
close to allow any measurement of separation in the astrometric but position angle was estimated very roughly at 245 degrees(three readings averaged).

Well worth the time spent and a definite "1".
Rating (1(best) - 5(worst))      : 1

Ambience: A beautifully mild night following on from an overcast day, this was the first clear night for over a week. Once set up at 22:00 there was an agonising 30 minute wait as the previously clear sky clouded over again but once that had passed it was as clear as a bell. Seeing was the best I have ever experienced allowing much higher magnifications (much needed for Gamma Vir) and transparency was also a bit better than average with fewer intrusive lights than normal as most neighbours were already tucked up safely in their beds before Monday brought a return to the daily grind.

This was only the third observing session since the garden landscaping project was finished. Observing now takes place in a paved courtyard planted with a multitude of herbs rather than on soggy grass and the overall ambience is much improved as a result (although I haven't dropped an eyepiece yet). The smell of the curry plants in particular wafts through the night air adding to the overall feeling of relaxation as the first object is acquired.
 

Ambience...Quiet eveing.  The 4 walls on the observatory gives a cozy feeling.  No rock bands this nite, and couldn't hear the ducks above the breeze.  One of the neighbors stepped outside to clear his sinuses, (something he does much to often for my liking....) Otherwise, just me and my thoughts....

I let the tubes cool for quite awhile and started viewing at approx  10:30pm local time (0430 UT). Porrima was about as high in the sky at my latitude as it was going to get.

The good news was that the seeing had settled somewhat. In the LX90, I was able to detect the elongation and split with a 12.5mm Ortho (160x). With a 9mm ortho (222x), it was more apparent and at 266x (7.5mm), the black space between the two similar discs was clear and easily seen. Using a 5mm vixen silvertop, the split was still quite clear, but seeing was introducing quite a bit of dancing and diffraction around the discs.

A moment later, I moved over to the Intes-Micro MN56 5" mak-newt. I 
have not really used this tube much for this type of activity. 

First look with the 9mm (84x) quickly reminded me of the short focal 
length (760mm)- couldn't see anything but nice pinpoint stars. Insert the 2x Ultima Barlow with 9mm (168x)... ahh, now I see elongation and discern what I think are side by side discs, but no space between. The 5 inch tube seems a little steadier as far as the object dancing. Go to 7.5 with barlow (202x)... definitely two discs, nice round airey discs, steadier than in the LX90, but don't see that space in-between - looks like two discs hugging each other. Bounce it up to 304x using the barlowed 5mm. View is nice - but I'm still looking at two discs "touching" each other with barely a hint of space between them. That's as far as I went this time out.

My conclusion - I like the views in the MN56 very much, more than the LX90 as far as the airey discs and the contrast, but the resolution on my tube seems a little stingy - a 5" should have about 1" theoretically. I would have thought the split with Porrima would have been more distinct. Will be fun to try it under a dark sky with steadier seeing conditions.
 

Further info: In my 1957 edition of Norton's, the following footnote appears: "A fine binary with a period of about 180 years. Its orbit is very eccentric. In 1780 its distance was 5".7 (sic)/ It closed up till in 1836 (0".3-0".5 d.), it appeared aingle in all but the Great Dorpat refractor (9 1/2 in. aperture), which elongated the star. The pair then widened, becoming an easy telescopic object, and reaching its widest (6".2) about 1920. Ii is now (1939) slowly closing, and will again appear single, except in large instruments, about the year 2016."