Shocked and stunned !

[John]

I'm slightly nervous about posting this but I'm amongst friends so here goes.

I've been using my Tak 100 refractor to observe double stars this evening but I noticed that the sky transparency was quite good so I've also been challenging the scope and myself to see how many galaxies I can spot.

I thought I was doing well in finding 11 in Leo, and quite a few in Coma Berenices, Virgo and Canes Venatici. The brighter ones were looking really quite contrasty for a small aperture scope.

I was going to have a look at the Markarian's Chain of galaxies on the Virgo / Coma B border but my scope wandered downwards a little into the bowl of Virgo and I saw a familiar starfield in the low power field of view  I was using. This was the field within which the galaxy IC 3322A is situated which is currently hosting a bright supernova, SN 2021hiz. I know this star field quite well having observed the supernova 3 times over the past few nights with my 12 inch dobsonian. North and south are reversed in the refractor of course but there is a distinctive line of 4 magnitude 8-ish stars to one side of the location of IC 3322A which is quite distinctive either way up !

Without any expectation at all I thought I would have a try at seeing the magnitude 12 stars close to the position of the galaxy and supernova. IC 3322A is barely, if at all, visible with my 12 inch scope so I knew that it would not be any sign of it with the 100mm refractor and that was the case of course. I did though manage to see a star which I know to be magnitude 12 and that was visible with direct vision at 38x magnification. So I upped the magnification to 90x and kept observing.

As my eye became fully dark adapted (this took about 30 minutes at the eyepiece) I started to pick out a magnitude 12.8 / 13.0 star which, with a brighter star, forms a triangle with the supernova. This star was seen intermittently but held for a few seconds when it did appear. I started to dare to think that I might actually be in with half a chance of detecting the supernova which is currently listed at magnitude 13.3. I increased the magnification again to 150x and again, as my eye became fully dark adapted and my mind got "into the zone" as it were, the magnitude 12.8 star glimmered and, not far from it and forming a triangle with the brighter star, another faint point of light was definitely glimmering as well. SN 2021hiz !

I was really not expecting this to be visible so I popped back inside to check the position charts for the SN, flipped one around to simulate the refractor view and then went back out to the scope. I needed another 20-30 minutes to get dark adapted again but the result, once I was, remained the same - I'm sure that I was seeing the supernova.

I have repeated the exercise again and replicated the result again, just to be sure.

Obviously having observed this supernova with a larger scope previously helped and the star charts I have for it are spot on. What I can't quite get my head around is how my 100mm refractor has shown me a point source target of magnitude 13.3

The limiting magnitude for a 100mm scope under a dark sky is generally given as 12.8 or 13.0. Maybe the SN has brightened a touch since the 13.3 figure was recorded (admittedly a day or two ago now). The magnitude 12.8 star did look comparable in brightness with the supernova this evening.

Anyway, as you can probably tell, I'm very excited to have seen this with my 100mm scope. Having repeated the sighting 3 times over the past 90 minutes I'm pretty confident that I have not imagined this very faint glimmer of light and I did gradually build up to being able to pick out these on the limit points of light through careful dark adaptation.

I will keep a very interested eye on other folks observations of this supernova to see if they detect a further brightening as well.

The rest of my session this evening was very enjoyable starting with the crescent moon and tiny mars but seeing supernova SN 2021hiz with my 100mm refractor has rather stolen the show !!!!!

I just hope anyone reading this does not think that I've gone a bit mad !

I've flipped and cropped an original excellent sketch made by @davhei a couple of days ago (I hope he does not mind). The green circle shows approximately the field I was getting at 150x:

Edited April 16, 2021 by John

[Stu]

Amazing John! Very well done, that’s a great piece of observing. I just checked on Bartel’s visibility calculator and it says a four inch can get down to mag 13.3 under mag 21 skies. With good dark adaptation, it looks to have been just about possible, which you have  proved tonight 👍👍👍

[Littleguy80]

Well done, John. Superb scope paired with excellent observing skills. Just goes to show what can be done! Very impressed. 

Edited April 16, 2021 by Littleguy80

[John]

2 minutes ago, Stu said:

.. it says a four inch can get down to mag 13.3 under mag 21 skies. With good dark adaptation.....

Thanks Stu and it's a bit of a relief to read that - most of the ones that I tried said mag 12.8-13.0.

I do wonder if the SN is around 13.0 rather than 13.3 though ?

The transparency was good tonight though - I saw 11 galaxies in Leo without much difficulty.

 

 

 

[Chris]

Well done John! It really must be the case if you triple checked. We've had a couple of nights recently of excellent seeing, and you've definitely made the most of that, congratulations!

[Sunshine]

Really enjoyed reading that, I know exactly what you are talking about because on nights of good seeing I find myself amazed when looking into a star field and the most

exquisitely faint stars begin to come into view. One, then another, and another seemingly fainter and fainter. Many times I have wondered about just how many I could see if

I allowed myself more time with a particular star field, I think giving our eyes the chance to see is the only way to truly reach the limits of our telescopes. 

[Saganite]

Excellent observing John ,really superb !

[jetstream]

Excellent John, definitely possible with high transparency and a scope with truly high transmission.

[mdstuart]

Well done John. As you know I am amazed how deep you get with your 12 inch. 

This again shows how much can be achieved with good optics by an experienced observer.

So the Horsehead in a 4 inch?

Mark

[mikeDnight]

That was a brilliant read John, as I felt I was with you all the way. Seriously great stuff! 👍

[Mark at Beaufort]

John this is an excellent report and a brilliant achievement. You only need to read Steve O'Meara's books to know what can be seen with a quality frac and an experienced observer.

 

[davhei]

Excellent report and it makes me glad to hear the sketch was useful. Well done!

Edited April 17, 2021 by davhei

[JeremyS]

Great result John. One factor is how much light is concentrated in the Airy disc. As we know, certain refractors have a great reputation for doing that. 👍🏻

[dweller25]

Good do John 👍

[Muc]

Wonderful read, that feeling of being shocked at the eyepiece is one of the best!

[Nik271]

Well done! It is encouraging that even 4 inch scopes can show so much! I'm sure a lot depends on the observer too. I have heard that in excellent conditions some people can see dimmer stars than mag 6, which is probably down to individual eye sensitivity and experience. One of my ambitions is to see the brighter moons of Uranus, at around mag 14 I thought this may be beyond the limit of my 180mm Mak. Now I am not so sure, should give it a serious try in the autumn!

[John]

3 hours ago, mdstuart said:

Well done John. As you know I am amazed how deep you get with your 12 inch. 

This again shows how much can be achieved with good optics by an experienced observer.

So the Horsehead in a 4 inch?

Mark

Thanks Mark - I think @mikeDnight has glimpsed the Horsehead with a 100mm 

[John]

1 hour ago, davhei said:

Excellent report and it makes me glad to hear the sketch was useful. Well done!

Your sketch has provided me (and others I think) with some excellent observing over the past few sessions

 

[John]

31 minutes ago, Nik271 said:

.... One of my ambitions is to see the brighter moons of Uranus, at around mag 14 I thought this may be beyond the limit of my 180mm Mak. Now I am not so sure, should give it a serious try in the autumn!

Well worth a few tries I think

I've spotted Titania and Oberon with my 12 inch dob but not, as yet, with a smaller aperture.

[Luke]

Well done, John! That was a great read and impressive result.  I think if I had to have only one frac, it might be my 100mm. A really nice balance of weight to aperture. If we get another clear night in the next few days, I'm tempted to dual mount my 100 and 85 for a general looksy.

Edited April 17, 2021 by Luke

[scarp15]

A credible observation John, particularly concerning your informed objective approach. The transparency across much of the UK has been I think exceptional this past week. When at a dark site a couple of nights ago and I took a series of magnitude readings after midnight and was astonished, actually thinking that my Sky Quality Meter was faulty, jumping from 21.55 to 21.62 and later higher 21.67 (last time there I think it hit 21.3). This likely enabled possibilities to reach a little deeper when scrutinizing particular freshhold targets (based on aperture) such as this. 

[wookie1965]

John fantastic observation you must have some great sky's according to "Clear Ouside" I am bortle 6 sky's to be honest I don't even know what that means except its not very good. 

Despite looking with up to a 8" reflector from home I have never seen M51 or the Leo Trio never mind trying anything 13mag. 

I suppose it helps to have a experienced eye although I have been doing this since 2012 you would think I had honed my skills better now. 

Congratulations on seeing the SN I have not even been able to confirm the one in Cassiopeia which I think is mag 8 so you have done extremely well and I am so jealous. 

Hats off to you sir. 

Best wishes 

Paul 

[laudropb]

Wow John. That really is remarkable observing. I tried for this SN with a SW ED 120 and my 8 inch Dob , but as expected with no luck. I must have another go. I keep telling myself I don’t need one of these Taks, but I am weakening.

[SuburbanMak]

Congratulations! 
That really is a testament to the value of experience combined with method & persistence. 

Fantastic read thank you & an inspiration for us smaller aperture guys!  

Now, the theoretical limit of my Mak 127 is 13.1.... 

[mikeDnight]

2 hours ago, John said:

Thanks Mark - I think @mikeDnight has glimpsed the Horsehead with a 100mm 

Glimpsed being the operative word John. It was on the absolute limit of discernibility, and was to date the most difficult target I've ever seen through a 100mm scope. Like you I'd spent quite some time allowing myself to become truly dark adapted, while being careful to keep Anlitak out of the field of view. It took a while before the nebulosity of IC434 began to reveal itself, after which, the black nebula seemed to become more obvious than the bright. What I presumed to be the Horse Head was very tiny and could only be seen with averted vision, hence my uncertainty about its exact positioning. It gave me quite a thrill though!

 

Edited April 17, 2021 by mikeDnight