The four Mousquetaires of the summertime

[Bertrand Laville]

Hi All,

The four big nebulae that are M 8, 16, 17, and 20 are very often observed, often sketched, but not often compared, specialy concerning their colours through big apertures.
Here are what I've seen, with or without filters.

Detailed reports are hereunder:
M 8: http://www.deepsky-drawings.com/m-008-t508/dsdlang/en
M 16: http://www.deepsky-drawings.com/m-016-t635/dsdlang/en
M 17: http://www.deepsky-drawings.com/m-017-t635/dsdlang/en
M 20: http://www.deepsky-drawings.com/m-020/dsdlang/en

Clear skies
Bertrand
http://www.deepsky-drawings.com/dsdlang/en/


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[kisspeter]

Beautiful drawings, Bertrand! Do you have descriptions in english? I didn't find them on your website. What I would especially be interested in is M 20. Did you use filters or did you see the bluish color directly (unfiltered)?
A colored drawing of M 20 has been in the back of my mind for a long time. But I've never seen it colored (16" max. so far).

[Bertrand Laville]

Hi Peter,

The Trifid is undoubtely the most color-contrasted Messier object.

Without filter, in spite the object was pretty bright, I didn't noticed any contrast of color: all is in a scale of grey.

When I began to observe the northern part, and, as everybody knows, being a reflection nebula, I used a CLS filter of Astronomik, with a ES 25/100° eyepiece. This filter has the same curve as the DS of Lumicon.
With this filter, all the Trifid, north and south, is blue; but the flower is very weak, in luminance and, of course in color. On the other hand, the northern part is seen with a vivid blue, that I scaled at C135/S30-40 in the usual scale of Paintshop Pro, or Photoshop. This part is prominent with the CLS filter.

When I decided to observe the flower, I used an OIII-12nm Lumicon filter. This device is an old filter of Lumicon, before the bankrupt, and it has a great quality: it lets pass the H alpha. With this filter, the bright stars are vivid and bright red (on the contrary of an other OIII filter of my own, which is an Astronomik filter, and through which, all the stars and nebulae are green).
The most striking of my observation was, as I looked at the flower with an Ethos 21mm and the OIII Lumicon, the flower was seen in red since the first second, whereas the northern part was totally "burnt out", even difficult to observe. I scaled the red at about C7/S30. The object with this filter was "an other" Trifid as the one I looked at a minute before.

All in one, I can't say that I saw the Trifid as drawn in my picture. This one is a mixture of what I saw successively, with to different filters. But such object, with such a contrast of colors, is very rare in the deepsky, at least to my mind.

Clear skies
Bertrand
http://www.deepsky-drawings.com/dsdlang/en/

P.S. My reports are not yet in english, but it is on my to do list !

[kisspeter]

Thanks, Bertrand. It could have been great to see the Trifid with that OIII filter!
My idea was to try a wide blue filter that does not pass OIII at all (+ an H-beta for the lower part). Thus use my eye a bit like a ccd detector. But currently I don't have such a B filter and I have never really tried this concept in practice. Hopefully it will come one day.

I understand you with the english translations. It's not my favourite things to do either.

[obrazell]

If you use the Chrome browser it will automatically translate it into English (or whatever the browsers default language is, so in Peters case possibly Hungarian. or you can cut and paste and use Google translate as a web page and it will do a decent(ish) job for you.

Owen

[kisspeter]

Thanks, Owen. Yes, Google Translate came to my mind after I posted my question. I'm not a regular user.

[Bertrand Laville]

Hello Peter,

You can know select the language you want in my website, and thus, read the notes of observation in english, or better, in hungarian !

[Raul Leon]

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