Very interesting field. At least 30 stars in the 0.6 degree FOV. Beta is the middle star in the long side of a distinctive 4 star asterism in the shape of an "L". Beta and it's companion point to a faint double about 10' to the SSE. A long line of three 10th magnitude stars bridge the gap between Beta and the double. The dim double is TAR 3ab (1851+33.2, Mag 10.9/ 11.4, Sep 13.1", PA 298). 
 

This system is a famous eclipsing variable with a 12.91 day period.  It has two minima (since the two stars are unequal in brightness)- 3.8m and 4.3m separated by a maximum of 3.4m in a 12.925 day period. 

Only 0.24 AU separates the Aa pair, so mass transfer must occur (at about 10^22 grams per second in a river that flows at 180 miles per second, equal to 10^-5 suns per year!).  Eventually, the accumulation of material on the companion may alter its physics to the point where it becomes a nova.  In addition, we now know that the secondary is also slinging off a stream of ejecta that forms an expanding spiral. 

The Aa stars are both oval-shaped owing to their strong gravitational warping of each other.  The dimensions of the larger star may be about 19 solar diameters by 13; for the smaller companion, it is probably about 12 by 9 solar diameters. 

Star A is 10 times the mass of the Sun; star a is 20 solar masses.  Note that the brighter star is the less massive; does Mass/Luminosity always hold?  Some astronomers think that the luminosity of star "a" may be reduced because it is surrounded by a (hypothetical) accretion disk.  The fact that the primary is also an infra-red source makes this a possibility. 

Beta Lyr stars are a fascinating sub-class, also known as W Ser stars.  They are always part of a binary system of two massive stars, one of which has aged faster and is a giant that fills its Roche lobe, meaning there is significant mass transfer taking place. This mass flow from the younger star to the older one results in an accretion disk around the old star. The variabilities in this disk lead to variable light output and if the viewing angle is just right (as it is in Beta Lyr's case), the disk will give the impression that the older star is brighter than it really is. 

The outer edge of the accretion disk can hide the "eating" star and make it look larger and cooler than it really is, making it appear to be a giant instead of the Main Sequence star it really is. 

First measure (1835) by F. W. Struve:  45.8" @ 150. 
The stars show similar proper motions. 

James Kaler's Star Notes: 
So many star names -- Vega, Deneb, Rigel -- ring familiarly to the ear. Sheliak, at the dim end of third magnitude, is not among them. Only because the little star is an integral part of the exquisite constellation Lyra, the Lyre or Harp, of which great Vega is king, does it even have a proper name. The southwestern-most star of the little parallelogram that makes the body of the Harp, and usually referred to as Lyra's Beta star, the name Sheliak derives from an Arabic word that refers to the whole constellation, to the celestial harp itself, which in Greek mythology commemorates the harp of Orpheus. 

Sheliak has an importance all out of proportion to its apparent dimness.  It is not one star, but two, a bright bluish hotter one with a temperature of some 13,000 degrees Kelvin orbiting a dimmer white cooler one (though one still much brighter than the Sun) with a temperature closer to 8000 Kelvin. Doubles of course abound in the sky. Our Sheliak, however, eclipses! The plane of the orbit is pitched so that dur 
Rating:  1 
 

The two mag.9 stars are readily seen and also appeared to have a yellowish tint.Could not find the 13th Mag companion mentioned in Burnham - hardly surprising since some twilight remained. Some of these latter are, it seems, probably only optical.
 
 
 

The primary appeared to be a creamy white colour with the listed companion a
blue colour. It took me a while to determine the position angle of the companion using this scope with a star diagonal, but I got there in the end. I estimated the PA of the companion to be about 150deg. Two other very faint stars could be seen near to the primary also. One at about PA 20deg and the other, needing averted vision, at about PA 320deg. A superb double star through any telescope.

Ambience: After a very clear sunset the sky looked promising with a very pleasant evening. Quite a number of bats were swerving round catching insects. Some of them looked very tiny indeed.  Perhaps this years offspring!  It was nice to see a barn owl pass overhead hunting for food over the gardens and fields. I wonder at how silently thesebirds can fly.
 

Star: Beta Lyrae
Date & Time: 22nd, July, 2001. 21:45 UT
Seeing: 7-8 <1-10 Seeing Scale (10 best)>
Transparency: 8 <0:worst -10:best >
Location of site: Quintueles, Gijón, Spain.  43º 32N, 5º 55W. Altitude: 20 m.
Site classification: Suburban
Sky darkness: 3.0 - 3.5 <Limiting magnitude> 
Temperature: about 16º C
Telescope: Zeiss Telementor
Eyepieces: 35 and 10mm Baader-Planetarium Eudiascopics
Magnification: 24x, 84x
Harschaw Scale: 2 <From 1 to 5. 1 = Great, 5 = poor interest>
 
 

Star: Beta Lyrae
Date & Time: 28th, July, 2001. 21:45 UT
Seeing: 7-8 <1-10 Seeing Scale (10 best)>
Transparency: 8 <0:worst -10:best >
Location of site: Quintueles, Gijón, Spain.  43º 32N, 5º 55W. Altitude: 20 m.
Site classification: Suburban
Sky darkness: 2.5 - 3.0 <Limiting magnitude> 
Temperature: about 18º C
Sky: Moon in crescent. A lot f cloud banks.
Telescope: Zeiss Telementor
Eyepieces: 35mm Baader-Planetarium Eudiascopic
Magnification: 24x
Harschaw Scale: 2 <From 1 to 5. 1 = Great, 5 = poor interest> 

Two more stars are in the field of view, composing a nice escalene triangle. It deserves frecuent visits.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

From my space-walk in Lyra, I go down observing and moving the telescope at 24x and then a bit towards East until finding Beta Lyrae. The split is obviously very easy. 

One of the components is white, while the another one
is orangish. Wonderful double star. Before ending the observing session, I go down again until finding Sulafat (Gamma Lyrae). This combo of telescope and eyepiece is very well suited to find M57, because when Beta and Gamma are in the same field of view, M57 is almost exactly in the eyepiece's center. At 24x M57 isn't visible, but at 84x it is using averted vision.
 
 
 
 
 

After aligning the Zeiss T-mount on Wega and adjusting the Sheilak coordinates, the split is again "entry-level" at 24x. The view is beautiful, with a very bright main component and a secondary clearly more fainter. The
body-position for observing isn't comfortable due to at this time of observation Beta is located at 74 degrees over the horizon

Ambience: This saturday is the zenith of local summer festivities in Qintueles and there is a lot of music coming from different "romerias" (concentrations of bands and people in the country-yard). Also, loud fire-works are perceived now and then. Since I've made previously a Moon imaging session and tomorrow we expect a familiar meeting in order to enjoy a professional "Fabada", I end up the observing session.
 

Description: The measures that I have carried out from the Amgle of Position
and Separation to this double are the follwing:

AP: 148.32º D: 46.11"

Data Catalog WDS.
AR: 18h50m06.00s DE:+33°22'00.0"
STF 39 AB
m: 3.63/ 6.69
1835: 45.7"/149°
1994: 46.3"/148°
Sp:B7Ve+A8p Na
DM:+33 3223
 

Many years ago, I carried out an interesting spectroscopic study of the main component using a Zeiss prismatic pocket spectroscope in conjunction with my 8.5-inch f/5 Newtonian reflector.  I found that the D3 helium line was almost always visible in emission, but the H-alpha line only occasionally.  There did appear to be some correlation with the variability period of the star, which would accord with theory, but the link was a rather weak one.  My investigation only served to confirm what astronomers already knew, which is that the human eye is a hopelessly inadequate detector for serious spectroscopic work!

In common with other members of this group, I could not resist examining the Ring Nebula (M57) while I was in the neighbourhood.  As on many occasions in the past, I found it obvious at all powers from x21, but improving with each increase in magnification up to x140.  This is, as is well known, quite a common effect with planetary nebulae.  Beyond x140, however, there was no further improvement.  I found the best view x84 and x140, at which powers I saw a lovely blue-grey smoke ring.  The central vacuity is not difficult with a/v, but appears smaller (and the surrounding bright annulus correspondingly broader) than in photographs.
 

At 70X the view was even better yielding the same colors and with M57 just on the edge of the field.
 
 
 

Comments: I observed this at low power as a dazzling White( v. mag.3.4-4.4)  star with a mag. 7.8 Bluish companion widely separated to the north. Two fainter companions emerge in the field to the south creating a Y-shaped asterism. Beautiful field and classic double. 

Ambience: My neighbour had such a successful day in the garden, as he helped his wife make preparations for an upcoming open garden exhibition, that he decided on a big burn-off. All through the evening burning timber, that great reminder of Summer camp-fires and the rich–smelling  aroma of  toasted incense, reminiscent of dim churches of long ago, filled the Spring air. The Moon, a yellow boat drifts westwards and my cat is back after a long winter sheltered on my back verandah. As I put away the eyepieces I realise that I have missed the obvious, Vega, a double from our list. My memory badly needs an upgrade! Is there some corner of the Universe  reserved for ancient star-gazers who have lost their marbles?