234 replies to this topic

[Tropobob]

I have been loosely following this for years. There was speculation that in would happen in the mid to late 1980s.

 

I just completed a quick look and unfortunately, nothing dramatic has happened tonight.  

 

Being in the south, my observing window will close late August, so I hope it happens before then.

[yuzameh]

It may have the perversity to occur during superior conjunction (well, it's not as if it could happen at inferior conjunction).

 

Anybody mentioned yet how many months that'll be?

 

Fortunately that will occur during Northern Winter, when it is far enough from the Sun to still be visible in the early hours, and the nights will be longer (well, unless you live all near the tropics or equator or summat).  Anyway, it will still be viable unless you have to sleep sometimes.

 

This'll be in November.

 

Because I myself insist it will fuse in November 2025, and most certainly NOT before this September, if this year at all, that's irrelevant.  However, keep looking, because what do I know?

 

HOWEVER, stop quoting authorities such as AAVSO or NASA websites.  The pre September prediction (which was a May 2024 prediction with a window from about Feb 2024 to Sep 2024) all comes from one paper by one scientist that everyone is quoting verbatim as respect the details, and they are all then quoting each other.  That's it.  No evidence above that, and that paper has issues.  You only have to read it to see them, very, very thin hearsay evidence for one potential past outburst for example is described as firm evidence if not proof in the conclusion, that is not science.  Meanwhile the other more solid evidence for the pre-1866 outburst is highly suggestive and feasible but has no independent confirmation at a time when the skies were still being fairly regularly monitored, if only to look for comets, which often don't care about the Zodiac and can appear anywhere in the sky.

 

Another professional who is a far greater expert on stars of this ilk, and how has observed and directly measured and studied many in his career, both photometrically and spectroscopically, and including the case of T CrB, says late next year too, with the modest caveat of that is only applicable if the same cycle count of orbits during the last gap needs to occur between outbursts, for which of course there is no evidence as only two certain and fully confirmed outbursts are known, and thus only one gap.

 

We'll find out finally in 2105-2106, after the great Water Wars of 2085-2099.  Put it in your diary.

[Redbetter]

No nova yet.  53 more nights in the 220 night wide prediction range.  

[stanislas-jean]

Thanks to Soyuz and Hubble for their pics.  Helped to roughly identify TCrB in my attempt.  At 3 mins, equates to 45sub @ 4 second. Any feed back welcomed.   Thanks and clear skies.  Pic totally unedited, png. 

The same exposure time doesnot equal the same results.

2" aperture against 4.5" aperture.

The question is to not overexpose the star in cause in order to allow the measurement of its magniture.

This imply the not overexposition of the brightest and the need of enough light collection for the faintest reference star.

The measurement correction has to be involved with the reference aperture in common use (67mm).

And be aware of the star IC, reason why specific filters are needed.

I have the evscope and we cannot filter easily the light collected.

With the ss50 we can insert the 2" filter into the light hood and take serie of shots, say 3 minimum by color channel,

and then apply the corrections.

Make sure the magnitude scale can envelop the T Crb magnitude: tests has to be undertaken to be sure, focusing of the star perfect with the batinov mask. The pin point has a surface that must be formed on several pixel (the case for such scopes). 

At final no treatment to be applied on the raw picture to keep the linearity.

That's a beginning. Variabilists may add something about this way of capture.

 

Better than expecting the date of bursting with explanations that seems to be wording for horse race.

We are on the period.

Sorry.

 

Nothing more yesterday evening the 20TH july.

Good skies.

Stanislas-Jean

Edited by stanislas-jean, 21 July 2024 - 04:28 AM.

[Redbetter]

No nova again tonight (or last night for that matter.)  Smoke haze cleared, and the Moon is less of an early now, so I've been seeing stars down to 5.5 mag in 18.5 mpsas sky in CrB.  

 

51 nights left in that 220 night window.  If we are lucky, it goes off sometime soon (meaning in that span.)  At least it remains fairly easy to check during that period.

 

The problem is that if it doesn't go off by the end of Schaefer's prediction range, it indicates a flaw in the "dip prediction" model.  In that event, the potential range becomes quite wide.  Schaefer's conclusion of the Dec. 1787 observation of the nova would result in a 78.4 year period.  However, if he is correct about the Autumn 1217 sighting, then the average period is likely greater, 80.9 years.  

 

The 78.4 year period came and went earlier this month.  The most recent cycle (1946) was 79.75 years.  That would put the next event in November 2025.  But if the *average* is instead 80.9 years, we could instead be looking at December 2026/January 2027. 

 

And that is just for what could be the middle of the long term range.  We already have indications that the recent periods can be as short as 78.4 years, if not shorter.  That would be 2.5 years short of the potential longer term period.  Assuming that there is likely to be as much variation on the other side would yield a range out to 83.4 years.  That would be July 2029.   

 

This could take quite a while.

[PeterSurma]

(...)

This could take quite a while.

Absolutely ! I was fine with Schaefer 's prediction. I'll also be fine with a later outburst. (Some other) People simply have become too eager to see something happening, well right now, now, now. Humans and novae, or astronomical objects in general live on very different time scales. We better relax about it. Still it's completely fair to discuss scientific reasons/mechanisms, sure.

 

Anyway the chances of personally seeing the blow-off rise as it goes are minimal. They are below 50% just by the fact that the sun is rising every day. Now the sun is approaching the position in alpha into the winter, so chances decrease even further. CrB will also move from evening to the morning sky, so much more unpleasent to take a checking look then. Then the timescale for the rise as such is so short (just a few hours). Weather, often very cloudy these days. Personal restrictions in observing times. You name it...

 

It's definitely an interesting object and I hope we can finally see it at maximum soon. I even admit that I regularily check CrB for a new bright star in the constellation. But I am prepared to wait until 2025+... ;-)

Edited by PeterSurma, 23 July 2024 - 01:16 PM.

[Redbetter]

Absolutely ! I was fine with Schaefer 's prediction. I'll also be fine with a later outburst. (Some other) People simply have become to eager to see something happening, well right now, now, now. Humans and novae, or astronomical objects in general live on very different time scales. We better relax about it. Still it's completely fair to discuss scientific reasons/mechanisms, sure.

 

Which one?    Since about December of 2022 Schaefer has made a wide range of predictions.  First he said ~2023 (link), then he said "2025.5±1.3" in March 2023 (link).  This was followed by the current prediction of 2024.4±0.3 based on the pre-eruption dip. (So that is a range from 2023 to almost 2027--predictions all made in the course of ~1 year.)

 

Rather than blaming this short term frenzy on the audience wanting things to happen quickly, I have the impression that the messenger has created unrealistic expectations of certainty about the timing based on the dip alone.  He could still be right, but it would have been more prudent to state that this is just a best guess about how the pattern will play out.   

 

It is good to have a graceful way of widening the prediction, if the eruption dip theory falls flat (as my chemist coworkers would say when we were trying to scale things up and things didn't work quite as predicted, "this is why we call it research.")  There is nothing wrong with saying one expects something to happen in the next few months, but it would have been wise to also warn folks that they could be in for a much longer haul.  

Edited by Redbetter, 23 July 2024 - 11:13 PM.

[Ihtegla Sar]

I was hoping the prediction was accurate so I would have a chance to see it. If it goes off between November and March I will have about a one percent chance of seeing it. Pretty much solid clouds for weeks on end during those months for me.

[Redbetter]

Down to 50 nights in the window now--although I can't see very deep tonight with smoke clouds/haze overhead.  I was topping out around 4.2 mag while I had two very clear nights in town that allowed me to see the arc of 5.02, 5.5 and 5.3 mag stars formed by eta CrB, omicron CrB and chi Boo respectively.  The darker of these nights was 18.5 mpsas overhead with the Moon low in the sky.

 

Schaefer has done some good work compiling and evaluating the various sightings.  However, there is one very irritating thing he states in a 2013 publication with regard to the refuted 1842 claim by John Herschel:  "Third, not only did Herschel apparently not see below sixth magnitude, but it is very unlikely for anyone to see to V=7.06 under any conditions."  Wow.  What an absurdly incorrect assumption...which he then goes on to refute by stating, "This is not to say that it is impossible to see to V=7.06 under optimal conditions, as, for example, I have recorded Stephen O'Meara (one of the premier visual observers for the last century) as seeing stars as faint as V=8.2 from the top of Mauna Kea."

 

The above says more about the author's NELM limitations than others, since in Schaefer's limiting magnitude study he said that he found O'Meara going two magnitude deeper when observing through the same gear side-by-side..  Many people see past 7 in truly dark sky.  Some folks can reach 8+ on the best nights.  Most nights at my primary dark site I can exceed 7.0, and rarely I reach ~7.5.   When I was young (but already starting to notice problems with my eyes focusing at infinity) I still reached 8.0 on Mauna Kea.  There are folks with better eyes than mine, particularly now since I have 0.5 diopters of myopia at distance.  Reality is that near threshold one will see some stars, and miss others of the same magnitude--that doesn't make the positives less real.

 

Fortunately for the subject observation, Schaefer was able to get around this problematic assumption because Herschel had made a transfer of this map in correspondence which verified the star, and he had been using opera glasses to go deeper than he normally would have.  Just because some individual doesn't normally record naked eye stars past 6 doesn't mean that others cannot.  

[yuzameh]

Which one?    Since about December of 2022 Schaefer has made a wide range of predictions.  First he said ~2023 (link), then he said "2025.5±1.3" in March 2023 (link).  This was followed by the current prediction of 2024.4±0.3 based on the pre-eruption dip. (So that is a range from 2023 to almost 2027--predictions all made in the course of ~1 year.)

 

Rather than blaming this short term frenzy on the audience wanting things to happen quickly, I have the impression that the messenger has created unrealistic expectations of certainty about the timing based on the dip alone.  He could still be right, but it would have been more prudent to state that this is just a best guess about how the pattern will play out.   

 

It is good to have a graceful way of widening the prediction, if the eruption dip theory falls flat (as my chemist coworkers would say when we were trying to scale things up and things didn't work quite as predicted, "this is why we call it research.")  There is nothing wrong with saying one expects something to happen in the next few months, but it would have been wise to also warn folks that they could be in for a much longer haul.  

Well said Sirrah!!!

 

or

 

Give that man a coconut!  Or several

 

or

 

Give that man a cigar!

 

or

 

Never a truer word spoken in truth!!!!

 

I'd forgotten about his other predictions.

 

I like his "2025.5 +/- 1.3", talk about covering your butt bet!

 

Indeed, I will be as annoyed as a very annoyed thing indeed (don't be a noid, we've got enough noids) if the thing goes flash at a time coincident with his last prediction.

 

Mostly because I want to see his caveat and replacement prediction.

 

It'll be just like the Sunspot Cycle prediciton, which was way off, so far off they repredicted it a little while ago (when it was well under way) and seem to forget about the prior prediction and the noise about "another Maunder Minimum due?" and pretty dead cycle this time.

 

WRONG.

 

And at the moment it still looks like the new prediction of maximum date could be premature by some months.

 

I predict it will happen when it does, if not the day before.  Now all I have to do is publish it.

 

I make no wonder astronomy gets a bad press for duds.  Green comets, T CrB will go boom, C/2023 disintegrate and/or major naked eye comet.

 

Yeah, right.  Looks like the professionals have invented the HYPErdrive.

 

There've been one or two other claims recently too that suffer large areas of wrong, quite evidently, because of sloppy researchj, such that even a thicko like me can see straight through it.
 

[stanislas-jean]

Hi,

The bet are open, push 2 cents in the machine, not more, no value to put more.

 

For the moment, T Crb is still glued at its level, as on yesterday evening the 24th.

It would be interresting to catch views  also in NIR segment for collecting premises of the event.

Good skies

Stanislas-Jean.

 

He! this is a forum for observing...

 

[Redbetter]

Hi,

The bet are open, push 2 cents in the machine, not more, no value to put more.

 

For the moment, T Crb is still glued at its level, as on yesterday evening the 24th.

It would be interresting to catch views  also in NIR segment for collecting premises of the event.

Good skies

Stanislas-Jean.

 

He! this is a forum for observing...

 

resized_T Crb 24.07.24 2min.jpg

Hilarious,  apparently you don't understand the difference between imaging and observing. 

 

Discussion of the mechanics behind the nova and how that might influence the timing is part of planning one's observing...whether or not you understand. 

 

We do discuss elements of what produces the DSO's we observe in this forum.  This is not a place where discussion of the science is actively discouraged.

[Redbetter]

Another actual observing point from tonight (7/26/24 UTC), no nova visible down to. 5.2+ mag. 48 nights left in the prediction, 22% of the range.  

[stanislas-jean]

You pushed your 2 coins in your machine for expecting your 2 coins theory.

It seems that observations involves theory at the issues...

That's better than imaginating surface of the comets...

Good skies.

Stanislas-Jean

 

Again this is a forum for observation results, not the contruary, this is making bla-bla.

You may create your forum for self-listening your writes.

[Redbetter]

You pushed your 2 coins in your machine for expecting your 2 coins theory.

It seems that observations involves theory at the issues...

That's better than imaginating surface of the comets...

Good skies.

Stanislas-Jean

 

Again this is a forum for observation results, not the contruary, this is making bla-bla.

You may create your forum for self-listening your writes.

Can anyone parse this word salad?  Dude, you have no clue what you are talking about. 

[yuzameh]

The below is a false statement and reveals that your images have no zero point calibration.

 

The ellipsoidal variation was first noted in the visual observations  in the BAAVSS dataset by John Isles over half a century ago, so eyeballs can detect it.  Over the period of time you have been observing it you should have seen a one tenth to two tenth magnitude variation.  Thus it is likely you will never notice the first stage of the outburst by simple visual inspection of the images until the thing has brightened half a magnitude at least when the skies are good, may up to one magnitude if they are not.

 

What's zeropoint?  Well, you don't necessarily need to do photometry, but if you look at your images closely you will probably find that the stars in the field, the constant brightness stars, don't all look the same brightness = 'size' from image to image, and the zeropoint needed is the level of the sky background.  You even see this in professional surveys if you look at only the initial fits images before the derived magnitudes are generated after photometric calibration, for no image has the same zeropiont as any other (it can be near, possibly even coincidentally the same, but not deliberately the same).

 

And THAT is why you consider the system's mechanics.  You have failed to note a variation that exists, a borderline non-negligible variation.

 

A naked eye observer giving a negative result pre-outburst is as valid as your images in that context.

 

I am not knocking your images, you are having fun, keep going, but don't get snooty about it and assume far too much based on your images.  It's only recently you've started marking T CrB's position on your images and it is still not immediately obvious from the images themselves what inversions, orientations, whatever your system provides, are, nor where North lies.

 

Summary : if you think the brightness of T CrB has been rock solid over your observing runs you are incorrect, it varies by very roughly two tenths of a mag every 123 ish days (all from memory, 123 ish is max to min, min to max, as the orbital period is 227 ish days.  Actually, I think that may be wrong, by definition ellipsoidal variabel have two maxima and minima per orbit, due to the mechanics of it all, and thus it should really be 62 ish days for max to min, and 123 is days max to max, min to min, and 227 days for two consecutive maxima or minima).

 

For the moment, T Crb is still glued at its level, as on yesterday evening the 24th.

[rjacks]

What has happened to this thread? What's it even about any more?

[stanislas-jean]

AGAIN, the challenge is to capture the burst all along its development (highlighted in posts above).

 

 

We are on the period as said by AAVSO.

We don't care of the forecasts of here and elsewhere said loudly...

Yuzameh, the pictures given here are jpg files...not fits.

This is to mention that the T Crb is still glued.

We have good soft, Siril for one who can exhibit magnitude stars with good references and refrenced procedures,

especially dedicated for the ss50.

Unistellar also has a program for the follow-up, are they wrong?

If something is appearing, we will go on other processus.

CLEAR!

Stanislas-Jean

 

"And THAT is why you consider the system's mechanics.  You have failed to note a variation that exists, a borderline non-negligible variation."

You failed in not reading all the posts...

Edited by stanislas-jean, 27 July 2024 - 05:29 AM.

[Redbetter]

From what I see, the only specific magnitude for an image that the OP stated was 10.5 on 5/5/24, but the magnitude system was not specified so that doesn't mean much.  Visual band was running 10.0 at the time (maybe a little brighter) in AAVSO submitted data, nothing really close to 10.5.  This was near the prior peak, and V band results averaged somewhere in the 10.3+ range during the recent minimum.

 

Rather than being "glued" the nova has been showing its normal variation cycle as yuzameh said.

[JohnH]

T CrB being what it is, accreting material off a nearby star in an elliptical orbit, it would make sense the outburst would occur on the inbound leg of the orbit as it gathers enough material to push it over the edge.

[Dave Mitsky]

I captured this image of T Coronae Borealis on Saturday morning, July 27th.

Attached Thumbnails

• 

[Dave Mitsky]

This image was captured on Saturday night, July 27th.

Attached Thumbnails

• 

[stanislas-jean]

From what I see, the only specific magnitude for an image that the OP stated was 10.5 on 5/5/24, but the magnitude system was not specified so that doesn't mean much.  Visual band was running 10.0 at the time (maybe a little brighter) in AAVSO submitted data, nothing really close to 10.5.  This was near the prior peak, and V band results averaged somewhere in the 10.3+ range during the recent minimum.

 

Rather than being "glued" the nova has been showing its normal variation cycle as yuzameh said.

Generally speaking, the acquisition conditions are rarely given, we have to imagine...

The ss50 has internally a 400-700nm bans pass filter and then sky conditions has to be reported also.

"Glued" means bursting didn't occur yet or nothing indicates that something is on going at once.

When something will occur, the insertion of the green johnson filter will be necessary, and the others B and R.

What happens before the peak doesn't interest, the dip was already done and the fluctuations recalled proudly are reported already by thousands observers.

What is visual band? for photometry.

Good skies.

Stanislas-Jean

[Redbetter]

Still no kaboom.  I estimated the visual magnitude a few minutes ago as 10.2 at 5:20 AM 7/31/24 UTC.  This was at 62x with the AT72EDII in town ~5 NELM, clear in this direction, while edge of smoke haze is stretching from NW to NE.

 

We are at 43 nights remaining in the prediction, 6 weeks.  This is less than 20% remaining of the dip prediction window.

 

Since the only decent estimates we have are of the last two periods, I am going to put my marker in for the most likely eruption date centering somewhere on the average of the two lengths:  the ides of March (3/15/25).  The reality is that with only two points, we have no idea of the actual long term frequency of the nova or how much that might vary.  It could be years from now, or tomorrow night.  

[yuzameh]

For practice purposes people could play with the just announced new nova in Vul, which'd be good practice for the fading part of T CrB, as that will last far longer than the outburst and maximum, and if it emulates the previous known outbursts (not suspected, known) will have a rebrightening hump of some interest after a time period.

 

I give no links, use websearch, but not google, else you'll end up being umpteen pages in before you find anything.  For good astronomy info you need non-google websearches with an adblocker and also the areas of the results with sponsored bits removed with an element hider.  I see this as the only reason I am able to find things that others here at times say they'd like but somehow haven't found it.  Such practices allow the basic search algorithms and weighting algorithms to do their job as they were designed for, without the on the top ads and sponsored muck getting in the way, and it is easier to block those on non-google systems without the thing breaking and not working at all.  I messed up the other day and forgot to undisable a feature I usually have active when looking for some astro stuff on youtube and had forgotten how much log in to your google account nagging normally goes on without the option enabled.

 

Ain't USofA got any anti-coercion laws?