harrym

Big outburst from mag ~16.5 to 11.5 reported a few days ago. Comet is in Draco, well-placed for observation if the sky ever clears up. https://groups.io/g/comets-ml/topic/12p_pons_brooks_in_outburst/100266541

Observed this with the 12" Northumberland refractor. It's already brightened to around magnitude 12! Managed to spot the ten NGC-designated star clouds in M101 too; some were pretty difficult, e.g. NGC 5451 and NGC 5458.

SN 2023bee in NGC 2708 was discovered a couple of weeks ago. I estimated its brightness at magnitude 13.2 last night. It was much easier to see than its 12th magnitude host galaxy. The SN appears to be outside the outermost visible reaches of the galaxy, but deep images show that it has faint tidal tails caused by interactions with some other galaxy (NGC 2709?) and the SN is probably in one of those, though I guess a halo globular is also possible. See the image below from Manfred Mrotzek, posted on David Bishop's site. NGC 2708 is the unmarked galaxy below the SN.

Returning to this thread 5 years on to report that I finally managed to see Andromeda's Parachute as non-stellar with the Northumberland refractor on Thursday night. At 218x it was just visible with averted vision as a faint "star" of magnitude ~15.2. Seeing was good enough that I was able to move up to 762x (an 8mm Delos) - at this magnification the quasar occasionally appeared as a very faint slightly elongated smudge. I was unable to resolve it into separate components, though it's possible that sometimes I only saw one at a time.

Been a while since I've been on here, but I made an observation last night with the 12" Northumberland refractor in Cambridge that I'd like to share. As everyone knows, the usual answer to "how many moons of Jupiter can you see with a telescope" is 4. The 5th brightest moon, Amalthea, is 14th magnitude and orbits even closer in than the Galilean moons so it's totally lost in the glare even with very large scopes. The easiest non-Galilean moon to observe is actually the 6th brightest moon, Himalia, which is around 15th magnitude but orbits so far out that it can get almost a degree away from Jupiter, so glare isn't much of an issue. Now that Jupiter's getting higher in the sky again, I decided to give Himalia a go this year. Jupiter is very close to perihelion which helps. The first challenge is finding out where Himalia actually is: Stellarium gets its position very wrong, and SkySafari is closer but still off by a couple of arcminutes. Occult 4 gets the position correct, as confirmed by checking against JPL Horizons. The next step is to plot the position on a star chart that shows stars fainter than Himalia - SkySafari will do for this purpose, and I used DSS images to confirm there were no missing stars that could masquerade as the faint moon. My first attempt was a few weeks ago, but it was made at the start of morning twilight and that may have put paid to my chances of seeing Himalia. Last night was a better opportunity. Himalia's magnitude was listed at 14.7, which is within the range of the 12" refractor, but the light pollution dome from Cambridge in the east brings the limiting magnitude down a bit on that side of the sky. I used a 28mm eyepiece giving 218x magnification; Himalia was 55' away from Jupiter, or more than two FOV widths. It made a small triangle with stars of magnitude 12.3 and 13.6 which made pinpointing the position easy. Sure enough, with averted vision a faint "star" kept popping in and out of view at the right position. Himalia appeared a little fainter than a star listed as magnitude 14.8 by UCAC4, so maybe the listed magnitude of 14.7 is slightly optimistic. Serendipitously, there was a galaxy in the field of view too: NGC 132, a magnitude 13.7 spiral, which unsurprisingly was a new object for me. For anyone who'd like to try this out themselves: this new moon is a particularly good chance, as Himalia will be getting closer to Jupiter until it's only 19' away on 6 October. Visual observation will require at least a 12" scope unless you're in very dark skies, but imagers should be able to catch it with smaller scopes.

Just saw this quasar again. The conditions weren't nearly as good as last time, but I think it's a bit brighter now than it was in August. Back then it was fainter than the star I marked "14.9?" on my chart which I posted earlier in the thread, and I estimated it was around magnitude 15.2, but this time it was the same brightness as the 14.9? star or maybe even a little brighter - perhaps 14.8. Now's the time to give it a go before it gets fainter again!

Quasars are often variable so it could change brightness, yes. But as it's only recently been discovered we don't know anything about its light curve. It seems to have been recorded as a magnitude 14.9 'star' in some catalog (can't remember which one), whereas combining the magnitudes from the initial paper suggested 14.5, and visually it seemed more like 15.2. As these measurements were all at different times I guess this could be a sign of its variability?

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.

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.

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

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.

Thanks for these! Not sure why the two images are showing different positions, but the first one is correct - it's the 'star' almost centred in the crosshairs.

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!