Star: Epsilon Hydrae
Date & Time: 07 mar 2002, 22.00
Seeing: 5 <1-10 Seeing Scale (10 best)>
Location of site: Annen, The Netherlands
53ºN, 6ºE
Site classification: Village backyard
Sky darkness: 5 <Limiting magnitude>
Transparency: 8 <1 worst - 10 best>
Temperature: 5º C
Telescope: Intes MK-67
Eyepieces: Ultima 30mm, LV 15mm, 10mm plossl 
Magnification: 60x, 120x, 180x
 

Star: Epsilon Hydrae
Date & Time: 16 mar 2002, 21.00
Seeing: 7 <1-10 Seeing Scale (10 best)>
Location of site: Annen, The Netherlands
53ºN, 6ºE
Site classification: Village backyard
Sky darkness: 3.5 <Limiting magnitude>
Transparency: 3 <1 worst - 10 best>
Temperature: 10º C
Telescope: Celestron C11
Eyepieces: 20mm Plössl
Magnification: 120x 
 
 
 

The next night the seeing was somewhat better and having the MK67 out I tried again on this pair, using the 10mm plossl (180x). But again no split...
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Did I look at the wrong star with the C11 last week? I start to doubt...
But it might well be possible, this is not an easy double with all this bad seeing in our watery Dutch skies. The C11 will be much more sensitive to seeing then the MK-67...
But the ease of split of Epsilon was somewhat amazing. First trying 180x I noticed that the little companion was easily visible at some distance from the deep-yellow, bright primary. Quite a nice view actually.
Going down to 120x the result was the same and the view even better. The small pinpoint secondary was sitting very close to the deep-yellow dot of the primary, but still separated by a narrow belt of dark sky. Wonderful!
60x was to much to ask. I couldn't detect the secondary any more at this magnification.
The nice view of the little pinpoint secondary that close to the deep-yellow primary gives this pair a rating 2.

Ambience:
Spring is here! 
Although the wind was strong and the temperature only a few degrees above 0, the signs and feel of spring are present. Out in the field, when observing Ikeya-Zhang, groups of Lapwings were heard in the meadows, busy sorting out their social relations. Typically a sound of spring dusks. Later in the evening the recently arrived Oystercatchers in the field around our village could be heard. Very noisely present with their loud Te-Peet, Te-peet calls. Little groups of Smew (duck species) were flying by, whistling gently and heading North.
And galaxies are in the sky...
 
 
 

Epsilon posed like a real beautiful model before the C11 this time. The ease of seeing the secondary, its brightness and "enormous" distance from the primary make it hard to beleive that this pair can be so tough in less favourable conditions. A very rewarding view, which is rewarded with a drawing that will help remembering how pretty this model was.

Only primary yellow star is seen at 44x (20mm TV Plossl). Secondary is detected at 73x (12mm TV Radian) in moment of steadiness.  The secondary was just touching the primary at 110x (8mm Radian), pin pricked.  A clean split at 146x, secondary color is also yellow.  Best view at 176x with a wide separation.  Forms almost a square with three dim stars GSC 224:951, GSC 224:715 and GSC 224:363.  Being that Hydra's head is formed by the stars: rho, delta, eta and esilon, could it be that Hydra was sprouting a new head ;-)?

Could not split @80x.

Definite elongation @145x just N of W with occasional brief glimpses of much dimmer secondary. Then, in a moment of still air, clear, definite, separation for about 2 seconds. Primary yellowish white. No colour evident in secondary.

This was difficult (DI 93.6) due to the large magnitude difference, but ultimately very rewarding. Higher magnification didn't really help with this one.
 
 
 

A tough one to crack with a small telescope, well worth the effort if 
you succeed.

13th March 2002.
Through the 200mm reflector at X60 I observed a lovely pale yellow 
star.

Using X200 revealed what appeared to be a pale purple companion (in 
moments of steady air) very close to the yellow primary star.
The 9mm(X133) orthoscopic gave the best view though. As the star 
drifted across the fov I could clearly see the companion during 
moments of steady air. Using X133 the very close companion appeared 
almost pink but occasionally I saw a powder blue colour.

The poor weather split on 15 March for a few hours. The sky was very dark and transparent due to all the rain ,and some snow, that cleaned out the air. Comet Ikeya-Ziang was an easy naked eye object and nice in any small RFT or binocular. I tried my 11x70 binocs, 4 inch RFT and 60mm Meade ETX and they all gave similar views. Hydra was not high enough in the sky during the early evening so time was spent in Orion viewing the sights. Air steadiness was only a 4/10 and signs of clouds advancing on horizon so on to the snake! Time to check out my new video camera from Supercircuits; a PC164C with a lux rating of 0.003, should be 2 magnitudes more than my PC23 with a rating of 0.04 lux. 
 

Notes: Found in the head of the Hydra. This easy to locate star will present a challenge to most scopes under 10" Persistence is the key in anything but the best sky conditions.
 

Ambience: After about 10 days of a low pressure system centered over Spain this last week a high pressure system came in to give us some clear weather. I was able to get out to the village last Wed and Thurs to get in some observing time. Spring has arrived and all the trees are in flower and the countryside is a brillant green with the rain we had. The weather was very mild to observe and the only downside was that some farmer nearby had sold off some of his bigger calves and the cows were bawling the whole night looking for their offspring but that is life on the farm.

I had noted from the Hydra Data that Epsilon has the highest DI rating and that some of the group had trouble splitting this double. The seeing looked favorable and I decided to set up the Meade 7" Mak Cas on the Losmandy GM8 with a 9mm Nagler to give me a magnification of 300X. The Meade Mak Cas has excellent optics and I would compare it somewhere between a 5" to 6" AP refractor. At least I have the right to think that. The longer focal length of 2670mm of the Mak Cas would help to split the double.
 

Reading the observations in the group web page a very big variability in the magnification necessary to split it can be observed. 

On the second night after photographing the comet I-Z I aim to epsilon Hydra. The seeing was like in the previous night among 2"-2".5, I split it almost continually at 83x and perfectly at 123x. Primary yellowish white and no colour in secondary. 

Luis has told me of the existence of an very interesting article in S&T April of 2001 signed by Sissy Haas. According to her comments with their double refractor 5" f10 she is unable to split epsilon Hydra. In this article we can see a formula proposed by the double observer Manuel Cortes from Spain to calculate the necessary minimum opening to separate doubles with an difference of magnitude. In this expression only two parameters are involved (separation and magnitude diference), but in my opinion the experience won in this group demonstrates that the seeing and the optic quality of the instrument are fundamental parameters in the capacity of splitting doubles. Not only the optic quality influences but it is also very probable that the optic design does it. For this reason these "empiric" rules are correct as a first approach because they are adjusted to particular conditions that cannot be extrapolated to all the observers and their telescopes.  In the article there is another rule calculated by Thomas Lewis
(1856-1927) which is evident that it is not adjusted to our average current telescopes.
 

Star: Epsilon Hydrae
Date & Time: 11th, April, 2002
Seeing: 6-7 <1-10 Seeing Scale (10 best)>
Transparency: 7 <1-10 Seeing Scale (10 best)>
Location of site: Auckland, New Zealand. 
Site classification: Suburban Backyard 
Sky darkness: --- <Limiting magnitude>
Telescope: Zeiss APQ 130/1000
Mount: Zeiss Ib mount, setting circles.
Eyepieces: Zeiss 0.965” orthoscopics,
4, 6, 8, 10 and 12.5 mm, H 40, Zeiss 4 ocular turret. 
Zeiss 2X barlow lens.
Magnification: 63x, 80x, 166x, 250x, 333x, 500x
 

Yellow and White/yellow although at 166 X secondary appeared blue at times. Contrast effect maybe???  No sign of third star although my skies are hardly dark.  A nearby race course does not help!!!??.

Very uneven.  Altitude of star when observed approximately 35 degrees.  At 166 X double apparent 50 % of the time.  At 250 X 100 % of the time.  PA quoted seems about right. 

Tonight, using the C-11, and early in the evening (less than an hour after sunset), in skies I would rate as 6 for seeing and 8 for transparency, I split Eps with 339x and a diffraction mask. Knowing now where to spot the companion, I removed the mask and still got it.  Then I dropped to 193x, and finally to 115x, seeing B clearly at all magnifications. I would say tonight though that it looked to be pale orange.  The C star was easily seen, but again, color not determined.

Struve discovered the ABxC pair (at 3.2" in PA 196) in 1830.  In 1912, Bowyer measured it at a PA of 240.  Heintz has an orbit of 890 years.

A is also a spectroscopic binary (9.9047 day period) and an infra-red source.

Schapparelli split A into 4.5 and 5.0 mag stars 0.2" apart in pa 142. Aitken computed a 15.3 year period for the AB pair.

Webb said it was a remarkable system and noted colors of yellow and blue.
 

Ambience: I was beginning to think it would never happen, but I finally got out last 
night. First time since November.
There were a few snags along the way. The DSC cable got snarled in the altitude arm. Unplugged it, got it unsnarled, and did my two-star alignment. 
Started to zero in on M35, my favorite OC, before it got too low in the sky. 
And the numbers on the box just sat there, unchanging.

Note to self: it's a good idea to plug the cable back in after unsnarling it.
About a half-hour later, the box died. I knew it wasn't cold enough . . . it 
kicks out below 30d F. (-1 C) Apparently the battery was low, which surprised 
me as it showed about half charged when I loaded the box up last week. At any rate, I replaced it and everything went well after that.

There's not too much ambience in a suburban townhouse setting, but some time 
after midnight, an owl started up somewhere in the neighborhood. Sort of 
spooky!

Along with the Hydra doubles and a couple of galaxies, I threw in a favorite 
of mine, STF 1659 in Corvus. Robins, baseball and STF 1659. It must be spring!