Gamma Virginis and Alpha Herculis

[AlcorAlly]

Last night I spent about an hour looking at Gamma Virginis and Alpha Hercules, also known as Rasalgethi. The seeing was very good, and so was transparency. I used a 4-inch f/9 refractor and a 65mm aperture mask to compare the views. The eyepiece was 4mm TV Delite delivering 230x.

Gamma Virginis
At 4" two perfectly matched light gold stars with overlapping first diffraction rings.

With the 65-millimeter aperture mask, the view was even more pleasing. The Airy disks were very close, with a thin but distinct black gap between them. The stars had very faint, barely visible diffraction rings that overlapped beautifully. Because of the close proximity of the Airy disks and the gently overlapping diffraction rings, I found the view particularly pleasing with the 65-millimeter aperture mask.

Alpha Hercules
The presentation was exciting through the 4-inch refractor. The primary star appeared fiery orange with subtle hints of red, while the secondary was a bright, distinct turquoise blue. The companion had its own very faint diffraction ring.

With the 65-millimeter aperture mask, the view lost some of its intensity. The primary appeared warm white rather than intense orange, and the secondary was much paler. A slight bluish tint remained, but it was very faint. This observation is consistent with my notes from September 2023 when I observed Alpha Hercules with a 3-inch refractor. At that time, I noted it was a beautiful star with a perfect single diffraction ring, a warm white primary, and a secondary with a very subtle turquoise tint.

The composition was very nice at 65mm, with the secondary sitting right on the edge of the first faint diffraction ring of the primary.

Last night's nearly full moon may have impacted the presentation of the colours, but overall, I felt that, unlike Porrima, Rasalgethi really benefited from the extra aperture. The colours were delivered more strongly, making it a dramatic and intense presentation, very beautiful and full of energy.

 

 

Edited May 20 by AlcorAlly
Added W orientation

[SwiMatt]

Love these, @AlcorAlly, keep them coming! And thanks for the descriptions and notes that come with the sketches.

[josefk]

Really nice renderings @AlcorAlly and i enjoyed the notes. 👍

I think i prefer the larger aperture in both cases too though i appreciate the "narrow" split appearance of Gamma Virginis in the 65mm and the secondary component sitting on the diffraction ring of Raselgethi with that same aperture too.

[AlcorAlly]

Thank you @SwiMatt @josefk for your kind and encouraging feedback.

[JeremyS]

Simply splendid 👍🏻

[YogSothoth]

Really good sketches. Can I ask what pencils you use? 

[AlcorAlly]

3 hours ago, YogSothoth said:

Really good sketches. Can I ask what pencils you use? 

Thank you! It’s a Staedtler mechanical pencil, one of these:

 

About 20 years ago I used to have the “original” version which had a nice weight to it. The modern ones aren’t the same but still ok. The sketches are done on white paper, then inverted on iPhone app with a dash of colour applied. 

I’m curious now what pencil you use for the solar sketches  

[YogSothoth]

On 02/06/2024 at 22:51, AlcorAlly said:

Thank you! It’s a Staedtler mechanical pencil, one of these:

 

About 20 years ago I used to have the “original” version which had a nice weight to it. The modern ones aren’t the same but still ok. The sketches are done on white paper, then inverted on iPhone app with a dash of colour applied. 

I’m curious now what pencil you use for the solar sketches  

Ah I see, thanks for that. I was wondering about the colour and thought maybe you were using coloured pencils, but adding colour with the I phone sounds like a good idea. I’ve tried using coloured pencils and it never looks right. 
 

I use a mixture Derwent Graphic and Derwent Precision pencils. The precision pencils are mechanical.