Cheshire Cat - my first use of a space telescope :)

[Yoddha]

Hello,

Gravitational lensing is predicted by Albert Einstein's general theory of relativity almost a century ago. It took 40 years till it was observed for the first time in 1979. It can be explained with older methods like apple and candle If you put an apple between you and the candle flame you will not see the flame. Moving your point of view up a bit, you can see behind the apple. However, if that apple is very massive it will bend the light and you will see that very same light without moving. So, in other words put something heavy enough in front and you will be able to see some things behind it. Even better, there is some magnification!  

How heavy should this apple be to act as a good lens?   Blackhole scale at least, but it is much easier with heavy galaxies clusters. They are like telescopes in space and we are looking through them Well, in fact there are more requirements in order the scope to be in focus - the lens mass, the distance between us and between the lens and the object are connected. So, not every galaxy cluster could provide a good view for us, most of the time there is nothing in the lens sweet spot or we are looking in the lens from too close or too far

This is not the case with Cheshire Cat - we have well focused imagen produced by the gravitational lens of a galaxy cluster! The "eyes" and the "nose" are huge elliptical galaxies dominating the small cluster SDSS J103842.59+484917.7 which is around 4.6 billion light years from us. Their light recorded in this image was emitted around the time our Sun was forming! The "smile" and the left contour of the face are the lens magnified images of four distant galaxies behind the eyes! Measuring the red-shift (0.966 according to https://iopscience.iop.org/article/10.1088/0004-637X/761/1/1/pdf) of these "images" is considered that background galaxies are around 10.1 billion light years away !!!

So, by double stacking my 250mm telescope with the SDSS J103842.59+484917.7 "space telescope" is possible to see something 10 giga light years away! What a travel in space and time!!!

(The reference image in bottom right is taken with a real space telescope - Hubble...)

Total 31h 45min in 8 nights in 2 years - L(107x900s bin 1x1), RGB(20x300s bin 2x2 each), RC250 @ f/5.5, ASI2600MM, CEM60

Acquisition : APT - Astro Photography Tool, PHD2
Processing: PixInsight, PS

[CCD Imager]

Great to capture something so faint. Your hard work has paid off!

Adrian

[davew]

That's really impressive Ivo and shows great dedication !

Cheers,

Dave.

[Paul M]

That's some image!

Gravitational lensing is the ultimate cosmic scale target for amateurs I think.

I had a go at the Cosmic Horseshoe earlier this year but my results were less spectacular!

[Yoddha]

Many thanks, Adrian!

 

[Yoddha]

Many thanks, Dave!

[Yoddha]

Many thanks, Paul!

The Cosmic Horseshoe looks very interesting. Did you finish the image?

[JonHigh]

That is absolutely awesome to capture that and your great description!! Good to know that even the cosmos has back focusing issues sometimes 😂 

 

 

[Yoddha]

Many thanks, Jon!

After all many complicated things reaches to simple things like apples, candles and focusing 🤣 In fact the biggest gravitational scope problem is the collimation 🤣