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Cosmic Challenge: Quasar 3C 273

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#1 PhilH


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Posted 01 May 2022 - 05:23 AM

Whenever my neighbor (I'll call him "Joe") sees me at one of my telescopes, he'll come over and ask "so, how far can you see with that thing?" Every time! You've also probably met someone like Joe. Well, unless you have a double-digit telescope, your answer should probably be "2.4 billion light years."

Click here to view the article
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#2 Benno


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Posted 09 May 2022 - 11:17 PM

I've seen 273 years ago thru my 8" Cassegrain. I think it's the farthest object you can see in a backyard scope!! Thanks for posting!!

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#3 Eclipsed


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Posted 13 May 2022 - 07:08 AM

I’ve seen it only on an image I took with my 8” SCT and ASI178MC camera. It was definitely a bluish shade. Since I know Phil’s emphasis is on visual and not Astro, I will see if we get a clear enough sky to try it with my aged and not-so-good eyes. It should be a fun challenge!

Edited by Eclipsed, 13 May 2022 - 07:09 AM.

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#4 Sky King

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Posted 13 May 2022 - 07:11 PM

3C 273 is my favorite quasar and I even started a thread on it a while ago. I plan to revisit it with my C11 and maybe boost it with a 2.5x Tele Vue Powermate, hoping to see some jets. Probably wishful thinking about the jets, but doesn't hurt to try. 

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#5 David Knisely

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Posted 18 May 2022 - 04:25 PM

I may have some doubt that most people with modest aperture telescopes will visually see much in the way of color in 3C-273, so using its "color" in the eyepiece to help track it down might not be a great idea.  At around magnitude 12.8 to 13.0, many people would probably need something in the 10 to 14 inch aperture range to notice any easily distinguishable hue at that low level of brightness.  Even then, the color index of 3C-273 is +0.21 which is comparable to a late A-class star like 3rd magnitude Talitha (Iota UMa), or magnitude 2.5 Alpha Cephei, and those stars visually are more white than bluish.  I may have to try to image it sometime to see what my old DSLR shows, but visually (at least to me), 3C-273 appears pretty much colorless. 

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#6 Special Ed

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Posted 18 May 2022 - 08:41 PM



This is a good challenge and also a very informative article about quasars in general and this one in particular.  I observed 3C 273 in April of 2018 using my C14, but I needed a very detailed chart to identify the star field.  As in your article, I starhopped from eta Vir to the NE.  I did not note any color to the quasar.  I made this eyepiece sketch.



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#7 Herchel


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Posted Yesterday, 11:42 AM

Thank you Phil for all the awesome stuff you do for astronomy.. 👍👍🍺
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#8 Dave Mitsky

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Posted Yesterday, 12:54 PM

I was able to log 3C 273 with my 101mm f/5.4 Tele Vue refractor in May of 2005 from Cherry Springs State Park in Potter County, Pennsylvania. I caught glimpses of the brightest quasar at 44x (12.4mm Meade Super Plössl) with averted vision. A distinctive stellar pattern lies slightly to the northeast of the quasar.

Information on and additional finder charts for 3C 273 can be found at the following URLs:




https://www.lsw.uni-...s/1226 023.html


I've observed a number of far fainter and more distant quasars using much larger apertures. 

There are lists of other quasars visible using amateur telescopes at these URLs:





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