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Bright lensed quasar discovered in Andromeda


harrym

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A quadruple gravitationally lensed quasar has been discovered in Andromeda - see https://arxiv.org/pdf/1705.08359.pdf and https://arxiv.org/pdf/1707.05873.pdf for images and details. It doesn't seem to have a proper designation yet, but it has been nicknamed "Andromeda's Parachute" due to its appearance. The combined visual magnitude is around 14.5, and it passes almost directly overhead, so it should be a relatively simple catch with a 12" scope, but splitting the components will require a much larger aperture.

The most amazing thing about this quasar is its redshift of 2.377, giving a distance of around 11 billion light years (at the time the light was emitted; it's now more like 19 billion). This means that if you manage to observe it, it may well be the most distant object you will ever see.

Now we've just got to hope for some clear skies in the next few months!

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Thats very interesting - thanks for posting the information :smiley:

Currently the most distant object I've managed to observe was the recent blazar CTA 102 which I believe was around 8 billion LY's.  This would top that, if I can see it that is !

It would be close to the limit of my 12" dobsonian from home but being high in the sky will help.

 

 

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Are you having a go at this one tonight Mark ?

A the moment I have a refractor out on double stars but I might put the 12" dob out as Andromeda rises higher. The Moon is also on the way up though, which is not ideal ....

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I'm definitely leaving this one till the Moon's gone - unfortunately that means I might not get a chance to see it with the 12" refractor before I go home on the 20th, and for six weeks after that I'll be stuck with just my 8" dob. So I'll probably have to wait till October.

Also the first image in Mark's post (with the correct crosshair position) seems to have disappeared, so here's one with the right object marked.quasar.png.8105253d09797eff44dd5192eaaba5c9.png

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Just had a quick look around the area with 10" SCT but couldn't see it, moony and misty here so probably why, weather not looking too promising for the weekend in this corner, folk further west and north may fare better.

Dave

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Harry, any chance of getting your hands on Roger Griffins 36" one clear night? :D:D Will say there is a well known saying that includes "snowflake" and "hell" that comes to mind. :laughing4::laughing4:

As it has just been refurbished - I think I heard they had redone the mirror also.

Nice shiny mirror, nice clean observatory, only problem is talking Roger in to it. :eek::eek:

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4 hours ago, ronin said:

Harry, any chance of getting your hands on Roger Griffins 36" one clear night? :D:D Will say there is a well known saying that includes "snowflake" and "hell" that comes to mind. :laughing4::laughing4:

As it has just been refurbished - I think I heard they had redone the mirror also.

Nice shiny mirror, nice clean observatory, only problem is talking Roger in to it. :eek::eek:

Not sure I could manage it myself, especially as I'm not at the IoA, but maybe someone else in the society could persuade him to let a few of us in *crosses fingers*. 36" should be enough aperture to resolve three of the individual quasar images, though the fourth one is pretty faint and would probably need an even bigger scope from the UK! The problem would be deciding what else to observe when you've got tens of thousands of objects to choose from ;)

Edited by harrym
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6 hours ago, mdstuart said:

Actually might have a go tonight. Andromeda is rising in the NE and the moon rises after nautical darkness. Lets see how close I can get.

Mark

How did it go Mark ?

The moons up and bright now but it was pretty dark earlier. I had my 4" frac out though so mag 14.5 was not on the cards !

 

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Ok first stab at this low down in the gunk with a lot of high cloud.

I can find the field of view and I can see the star just below and left of the quasar with direct vision.

I cannot see the quasar but I think that on a better night with the object higher in the sky it should be possible.

Mark

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Nice report Mark - the skies are not bad here tonight but could be a little better - I hope you get it another time :smiley:

I've been able to see a couple of mag 14.7 stars around M57 tonight with my 12" but thats more or less overhead so little atmospheric extinction. Didn't get the central star though. Must be close - probably needs a really, really good night with my scope.

Bloomin clouds coming over from the W now :rolleyes2:

Edited by John
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Hunted around for it until the Moon came up, using SCT @ 2500 f/l so very small FOV, can't make out if I'm in the right spot, got to go out all day until late now so no time to plate solve.

Taken with Atik 314L 

Dave

Capture_000_086.png.d498540d8ce06b19b5c0349b0fdef82c.png

 

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Mark by my reckoning you're seeing down to about mag 14.8 so the fact that the quasar isn't a single point source must be making it harder to see. Might be best not to use such high magnification as the brightest component is only about mag 15.5. We should get some better chances in the autumn when it passes almost directly overhead.

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Got it with the 12" frac last night just before 3am. I used magnifications of 215x (a 28mm Nirvana) and 300x (a 20mm Plossl) and could see it with both, but I don't think 300x made it any easier and the seeing wasn't perfect so I preferred the much larger field of view at 215x. It was a tough one - I could only see it with averted vision, and tapping the telescope tube helped. The image below is a printout of a DSS image of the region with the quasar and some star magnitudes marked. The "14.9?" is because I couldn't find a V magnitude for that star so I used UCAC4's fit model magnitude; after observing it I think it's actually a little brighter than 14.9. The quasar was noticeably fainter than the 14.9? star; I'd place it in the same difficulty bracket as the 15.0, 15.2 and 15.3 stars, which all appeared around the same brightness to me. I eventually got occasional glimpses of the 15.4 star and the two 15.6 stars with averted vision and tube tapping.

Mark, you must have been pretty close to seeing it as you noted the 15.0 star in your sketch.

20170820_115736.thumb.jpg.44699e133314cd0ef26146e8d852dc65.jpg

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