Heart Nebula

[MarkS]

Here is part of the Heart Nebula - IC1805.  Taken from Riberac on 27 Aug 2011.

57 x 5min with H-alpha modded Canon EOS350D at ISO 800 on a Tak Epsilon 180ED and using an Astronomik CLS filter.



Larger version (full frame but 2/3 scaled):
http://www.markshelley.co.uk/Astronomy/2011/heart27082011.jpg

In hindsight I'm not sure I got it optimally framed but I'm pretty pleased with it in any case.

Mark

[julian]

Very nice images Mark with fantastic detail as always.

[PhilB]

Lovely image, Mark. I'm left wondering what you might have come back with had the weather behaved!

[The Thing]

Another stunner. When's your coffee table book coming out Mark?   I was showing your website to a non-astro mate of mine last Friday and he was flabbergasted.  

Were you collecting subs from dusk to dawn? 57x600s is a long time. I guess the nights don't get so short even a few degrees south of the UK.

[MarkS]

Were you collecting subs from dusk to dawn? 57x600s is a long time. I guess the nights don't get so short even a few degrees south of the UK.

They were 5min subs i.e. 300sec
Even so, this amounted to around 5.5 hours of data collection in a single all-night session.  The hours of darkness are slightly longer down there in the Summer - it's 6 or 7 deg further South.

[mickw]

Another good one Mark, and again fantastic detail

[JohnP]

Mark - Great again. What I love about your images is the way they always have a 'misty' appearance - I think it must be to do with the way you process the foreground nebulosity... Not sure. Anyway looks great.

John

[Tony G]

Lovely image Mark, but can I ask a question, which maybe a stupid question from me, but one you might be able to answer.
If defraction spikes are usually caused by the vains which hold the mirror, or something which maybe obstructing the path of light, why is it that there are stars with 6 spikes (bottom and RHS) on the large version, but the majority only have 4. Like I said, this maybe a stupid question, but I just don't know the answer?

Tony G

[MarkS]

If defraction spikes are usually caused by the vains which hold the mirror, or something which maybe obstructing the path of light, why is it that there are stars with 6 spikes (bottom and RHS) on the large version, but the majority only have 4. Like I said, this maybe a stupid question, but I just don't know the answer?

Tony,

That's a very sensible question!

Diffraction spikes are caused whenever a straight edge interrupts the cone of light arriving at at area of the CCD.  The spider vanes do this and cause 4 spikes (the diagonal ones).  The orthogonal ones are caused by the camera design - the CCD is placed at the far end of a square "tunnel".  For pixels near the edge of the CCD, the straight edges of the tunnel interrupt the light cone and cause the additional spikes that you see (vertical or horizontal or both).

Hope that makes sense!

Mark

[Carole]

Very smooth Mark, no sign of noise.
Lovely image.

Carole

[Tony G]

Thank You Mark.

Tony G

[Fay]

Superb Mark!!!!


Fay