Double Quasar

[Mark Wagner]

Hi All,

I'm getting re-certified on the 30" at Fremont Peak next Saturday, and will use it for more or less specialty objects.  Here's one:

I recall years ago at Michelle Stone's Plettstone property, there with probably Alvin Huey and I'd guess Jim Ster, set up with their then co-owned (I thin) 30" Starmaster. I seem to recall we were looking for the Double Quasar in Ursa Major.  I don't recall seeing it.

Close to an easy NGC.

Interested in hearing about observations.  Of course there's info on Wikipedia and not surprisingly the second item here on ADS.

Anyone?

-- 
Mark
"Laissez le bon temps rouler"

[Mark Wagner]

At the bottom of the ADS page above, is a link to observations.  I wonder who's they are.. Jay McNeil? His name is at the bottom, but I don't know if it is for the Canes Venatici quasar or if its the entire page.

Still, others?  Anyway, the report on UMa twin indicates it should be very doable in the 30".

Mark

[Akarsh Simha]

Isn’t McNeil an imager who became famous for the discovery of a new reflection nebula that has since faded out:

https://en.m.wikipedia.org/wiki/McNeil's_Nebula

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[Howard Banich]

I was able to split the Double Quasar with a 20-inch f/5 Obsession several times in the 1990's. It took 600x or so on nights with steady seeing though.

Howard

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[Steve Gottlieb]

I’ve viewed it quite a few times — here’s an incomplete list of observations.  Obviously aperture makes a huge difference as the individual components are only mag ~16.7 and 16.9.  As far as splitting the pair in a 10” (seeing both simultaneously) I seriously doubt it, though someone with excellent vision, seeing and transparency might be able to glimpse it as a single blurry object.

The nearby bright galaxy is NGC 3079.

Steve

82" (5/4/19): at 613x; very clean split with both components easily visible continuously.  The southern "B" image appeared a few tenths of a magnitude brighter.

48" (4/24/25): viewed at 813x and 1084x.  At 6" separation, the pair was widely split at this high power and visible continuously as sharp points. The southern "B" lensed image was clearly brighter.

48" (4/18/15): both mag 16.7/16.9 components easily visible nearly continuously at 697x.  The southern component was clearly slightly brighter, although delta V is only 0.2.  At 6" separation, the pair is relatively widely split. The lensing foreground galaxy 2MASX J10012087+5553496 = YGKOW G1, which has a redshift of z = 0.356 (light-travel time 3.9 Gyr), wasn't seen.

48" (4/6/13): the mag 16.5/16.7 components were cleanly split at 488x, though easier at 610x. The southern "B" component was slightly brighter.

48" (4/15/10): the gravitationally lensed Double Quasar was very easily split in the 48" at 700x.  At this magnification, the two components, separated by 6" were widely split with lots of clean space between the quasar images.  The individual components appeared as perfectly sharp mag 16.5 and 16.7 stars oriented ~N-S, with the slightly brighter "B" component (delta V = 0.25) to the south.

18" (2/14/10): although it was not difficult to starhop over to the position from NGC 3079, the double quasar was glimpsed at 280x as a slightly fuzzy 16th magnitude star with averted vision.  The components seen only as a single glow (perhaps one component or the other).  Located just west of a group of mag 14-15 stars and 1.1' NW of a mag 14.6 star.

17.5" (4/15/99): the field of the gravitationally lensed twin quasars was easily found by quickly starhopping 15' NNW from NGC 3079 to a small asterism of six mag 14-15 stars.  The double quasar is situated 1.0' NW of a mag 14.5 star in the NW corner of the asterism.  At 280x and 380x an extremely faint 16th magnitude nebulous glow was intermittently visible .  Appeared slightly fuzzy but the individual mag 16.7 components, which are separated by just 6", weren't resolved.

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[Akarsh Simha]

My experience with my 18" was similar to Steve's reports with his 17.5" / 18". My experience with the 28" (Jonathan Lawton can corroborate) was much better: I was able to resolve the pair even though it was low in the sky. With the 48-inch, it's a piece of cake. Jimi likes to joke that you could drive a semi-truck between the components!

Regards

Akarsh

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