Colorful Globular


Roland Christen
 

https://www.astrobin.com/cnsikb/0/

Shot on Monday night on the Mach2 mount. Not the best transparency and heavy light pollution as well as smoke from western fires, but I did manage to capture some very faint stars. Tracking was done with Dec Arc model active and nudge guiding.

Rolando

--
Roland Christen
Astro-Physics


Jeff B
 

Ok Roland so after all of the excuses and qualifications from your post, I was expecting something less than stellar (HAH!).

WRONG!!

Good Lord man,  that has got to be the best image of M13 I've ever seen.  Period.  I LOVE the colors.  I LOVE the core!

Well done Sensi Rolando!

Jeff

On Wed, Sep 1, 2021 at 5:34 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:

Shot on Monday night on the Mach2 mount. Not the best transparency and heavy light pollution as well as smoke from western fires, but I did manage to capture some very faint stars. Tracking was done with Dec Arc model active and nudge guiding.

Rolando

--
Roland Christen
Astro-Physics


Mark Striebeck
 

I have to ask: what are those red halos?


On Wed, Sep 1, 2021 at 6:58 PM Jeff B <mnebula946@...> wrote:
Ok Roland so after all of the excuses and qualifications from your post, I was expecting something less than stellar (HAH!).

WRONG!!

Good Lord man,  that has got to be the best image of M13 I've ever seen.  Period.  I LOVE the colors.  I LOVE the core!

Well done Sensi Rolando!

Jeff

On Wed, Sep 1, 2021 at 5:34 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:

Shot on Monday night on the Mach2 mount. Not the best transparency and heavy light pollution as well as smoke from western fires, but I did manage to capture some very faint stars. Tracking was done with Dec Arc model active and nudge guiding.

Rolando

--
Roland Christen
Astro-Physics


Roland Christen
 


what are those red halos?
When you have a first magnitude (red) star in the image and it saturates in just a 1 second exposure, then imagine how much light comes into that position in a 20 minute exposure. Not only from the intense core of the star, but from the 1st, 2nd, 3rd, etc. diffraction rings that surround the core and spread light out theoretically to infinity, but also from all the moist air above, as well as the smoke from the western wild fires that also spread the light in a bright halo around any bright object. Go out some night when the moon is full and place your pinky over the moon and see how much glow you see surrounding our satellite. This kind of glow happens around all bright objects, stars, planets, even the sun.

In this case, the core of the star saturates and creates a white spot in the middle, but the halo is not saturated, so becomes red since the blue and green light is at a lesser intensity. It's a fundamental fact of any RGB image taken with an electronic sensor that has a limited well depth.

Rolando

-----Original Message-----
From: Mark Striebeck <mark.striebeck@...>
To: main@ap-gto.groups.io
Cc: main@ap-ug.groups.io <main@ap-ug.groups.io>
Sent: Wed, Sep 1, 2021 10:01 pm
Subject: Re: [ap-gto] Colorful Globular

I have to ask: what are those red halos?

On Wed, Sep 1, 2021 at 6:58 PM Jeff B <mnebula946@...> wrote:
Ok Roland so after all of the excuses and qualifications from your post, I was expecting something less than stellar (HAH!).

WRONG!!

Good Lord man,  that has got to be the best image of M13 I've ever seen.  Period.  I LOVE the colors.  I LOVE the core!

Well done Sensi Rolando!

Jeff

On Wed, Sep 1, 2021 at 5:34 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:

Shot on Monday night on the Mach2 mount. Not the best transparency and heavy light pollution as well as smoke from western fires, but I did manage to capture some very faint stars. Tracking was done with Dec Arc model active and nudge guiding.

Rolando

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


WMarton@...
 

What telescope was this shot using?  I have never heard of an AP 10 inch F6.3 Maksutov Astrograph.

Bill


Roland Christen
 

I've built a number of Mak-Cass astrographs and this is just another version that I've been using for test purposes.

Rolando

-----Original Message-----
From: WMarton via groups.io <WMarton@...>
To: main@ap-gto.groups.io
Sent: Thu, Sep 2, 2021 2:52 pm
Subject: Re: [ap-gto] Colorful Globular

What telescope was this shot using?  I have never heard of an AP 10 inch F6.3 Maksutov Astrograph.

Bill

--
Roland Christen
Astro-Physics


WMarton@...
 

Roland,

Thanks for your reply, I just found your in-depth description of the Mak astrograph on the other Forum.  Interesting scope.  I would love to see some photos of some of your prototypes and other scopes that never came to market.  I live in the Washington, DC area and it is always a treat to see the AP 206 EDF at Company Seven up close and personal.

Bill