A recent paper on ArXiv reports a novel idea about the central regions of "our" galaxy.
Remember the hoopla a few years ago about radio-astronomical observations producing an "image" of our central black hole - or rather, an image of the accretion disc around the black hole - long designated by astronomers as "Sagittarius A*" (or SGR-A*)? If you remember the image published then,
one thing should be striking - it's not very symmetrical. If you think about viewing a spinning object, then you'd expect to see something with a "mirror" symmetry plane where we would see the rotation axis (if someone had marked it). If anything, that published image has three bright spots on a fainter ring. And the spots are not even approximately the same brightness.
This paper suggests that the image we see is the result of the light (radio waves) from SGR-A* being "lensed" by another black hole, near (but not quite on) the line of sight between SGR-A* and us.
By various modelling approaches, they then refine this idea to a "best-fit" of a black hole with mass around 1000 times the Sun, orbiting between the distance of the closest-observed star to SGR-A* ("S2" - most imaginative name, ever!), and around 10 times that distance. That's far enough to make a strong interaction with "S2" unlikely within the lifetime of S2 before it's accretion onto SGR-A*.)
The region around SGR-A* is crowded. Within 25 parsecs (~80 light years, the distance to Regulus [in the constellation Leo] or Merak [in the Great Bear]) there is around 4 times more mass in several millions of "normal" stars than in the SGR-A* black hole. Finding a large (not "super massive") black hole in such a concentration of matter shouldn't surprise anyone.
This proposed black hole is larger than anything which has been detected by gravitational waves (yet) ; but not immensely larger - only a factor of 15 or so. (The authors also anticipate the "what about these big black holes spiralling together?" question : quote "and the amplitude of gravitational waves generated by the binary black holes is negligible"
Being so close to SGR-A*, the proposed black hole is likely to be moving rapidly across our line of sight. At the distance of "S2" it's orbital period would be around 26 years (but the "new" black hole is probably further out than than that). Which might be an explanation for some of the variability and "flickering" reported for SGR-A* ever since it's discovery.
As always, more observations are needed. Which, for SGR-A* are frequently being taken, so improving (or ruling out) this explanation should happen fairly quickly. But it's a very interesting, and fun, idea.
Il semble bien que l’intensité de la raie H_alpha augmente sensiblement depuis l’été dernier !
Which my Français-de-chien translates as "It seems that the intensity of the H_alpha line [in the emission spectrum] is considerably stronger now than last summer. Which was specifically one of the things Schaeffer was mentioning as needing close monitoring in his alert of 10 months ago. It hasn't "gone" yet, but that's what would be expected in the run-up to an outburst.
Merci beaucoup à Alain Lecacheux at [PSM observatory], Alain Figer, Al Grycan and Jean Lecacheuxfor the "heads-up!"
Overall, given the rapid and drastic increase in intensity and width of the Hα profile, we strongly anticipate that the T CrB outburst may occur soon.
Spectroscopy on Jan 15, 29 and Feb 07 continue to show rapid increases in the H&aplha; line, in both intensity and width (indicating a larger size of the accretion disc).
In other words, thinga are hotting-up.
Similar changes have been observed in other "cataclysmic variables" in thye run-up to recent outbursts, though none have the historical record of reaching naked-eye visibility that T CrB has. You probably won't need to carry sunglasses all night, unless you're wanting to pose.
I don't see other mention of T CrB in other ATels back to mid-January.
As submitted ; if posted to front page, I'll modify this to reflect the editing. .
Chatter on the "Minor Planets Mailing List" (an email list for people interested in the "small bodies" of the Solar system) indicate that the Tesla Roadster polluting interplanetary space since being dumped there in 2018 has been spotted again. Telescopes in four countries reported the object. From the object's brightness, it appears to remain attached to the Falcon upper stage.
Initially, the object was misidentified as a minor planet, but once there were sufficient observations to establish it's orbit, it's identity as a "rediscovery" of "2018-017A" was established. Since the object is not natural, it is of no further interest to the astronomers and the last batch of data have been assigned to "artificial object 2018-017A, Falcon Heavy Upper stage with the Tesla roadster". Some people here might be interested though.
"Is it coming back?"
Yes, as it does every 1.525 years. This will be it's 4th return.
"Will it hit us?"
No. This time around, it'll be about 0.1 years behind Earth where it crosses Earth's orbit (4 × 1.525 − 6), which would be about 94 million km away. The closest it'll come back is about 240 thousand km away — about 2/3 of the Earth-Moon distance.
I'm not sure if Elon left the keys in the ignition. Recovering it to Earth would be an amusing trick for Bezos. There should be no legal issues since the object was clearly abandoned by it's owner. Set your diaries for 2065-ish.
If it goes onto the front page, it'll probably be edited. Which is why I've got CSS for "Insert" and "Strikeout".
I think I've mentioned FreeFall - a webcomic here previously. … No, maybe not - it's not in my tag list. Well, it's an SF webcomic that has been running for ... decades now? I think found it because got mentioned for having a use of "on the third hand" which is an obvious reference to Niven & Pournelle's "Moties". Is good. You read. (Don't be upset by the hosting site not doing HTTPS:// properly.)
In discussion of the genetics of one of the species involved ("Bowman's Wolves", below), a "rule of thumb" from ecology was mentioned, which I followed up. Someone called "Franklin" had a rule that for short term survival of a species, you need a population of at least 50 individuals, and for longer terms survival, at least 500.
I followed that logical thread, and Read The Friendly Paper. Below are my contemproaneous notes from RTFP (translated from the original PHPBB markup.
cite="MaverickMopete post_id=840776 time=1735693995 user_id=1060" at least 500 Bowman's Wolves [the gene-engineered organism], according to Franklin's 50/500 Rule.
I don't particularly remember going "what?!" on seeing that the first time (whenever that was). Now I'm going "what?!"
The idea of effective population size (my emphasis) being different for short-term and long term survival sounds vaguely right. But it also flies in the face of the experience of every species that has originated (be that sympatrically or allopatrically), and most extension-of-range developments in mobile species. Living during a period of repeated ice age versus rain age conditions, sweeping across the globe and extinguishing one species making space for another to move in ... that's very challenging. Unless the emphasised effective population size comes into play quite strongly. One wolf making it across 500 km of hostile terrain per generation being enough to couple the isolated pack of a few dozen to a larger gene pool of hundreds or thousands means that the effective population size is thousands, not dozens.
Reference : I. R. Franklin, “Evolutionary Changes in Small Populations,” In: M. E. Soulé and B. M. Wilcox, Eds., Conservation Biology: An Evolutionary-Ecological Perspective, Sinauer, Sunderland, 1980, pp. 135-149.
("Ne" is the effective population size, in contrast to the "census size") :
Before developing this argument in detail, we should ask if evolutionary change is what we want. Do we wish to conserve the elephant, or ensure the survival of its elephant-like descendants?
Speciation is discussed in Chapter 9.
(I spotted that connection immediately - but maybe that's my history of trying to inject brains into Creationists using the soggy end of a ripped-out thigh bone.)
We can distinguish between three modes of selection for quantitative traits. These are: (a) stabilizing selection, or selection against extreme values; (b) directional selection, in which one extreme is at an advantage; and (c) disruptive selection, or selection for extreme values, and against intermediates.
(a) was a big problem for Darwin, when the discrete, "atomic" (sense "undividable", not sense "components of molecules") nature of the "particle of inheritance" wasn't understood. Cue a monk in a garden in Brno. Most of the classic examples of evolution-in-action (and particularly artificial selection) operate in mode (b). Everyone who has tried hard to impress a "potential mate" only to see him/ her/ it/ them go off with "pug-ugly" has seen mode (c) in action.
Someone mentioned "uncanny valley" recently. Mode (c) poised to leap into action.
It is well known that populations which have been through a bottleneck or which have been maintained at a small population size do not show as great a response to artificial selection as do large populations.
This is one of the things that makes me dubious about the regular claims of "Mitochondrial Eve" (an unavoidable statistical event) and a human "population bottleneck" at (various times, around Toba (a major volcanic eruption about 70 kyr BP, or pick-a-number around 100 kyr BP) Both of which were certainly after the dispersal of Homo erectus across Asia, and one is almost certainly after Homo sapiens had reached towards Australia. What actually happened most likely wasn't a single, simple event. Which doesn't make for neat headlines. (Note : this paper is approaching it's 45th birthday.)
Skipping some statistics :
Effective number is decreased by increased variation in progeny number and, conversely, Ne, is maximized when all families contribute equally to the next generation.
That's one to put into your "Practical Starship Genetics" guide book. It also, effectively means making not having children illegal and immoral. "You don't own you genome, you borrow it from your grandchildren, and if they don't exist, you don't. Into the recycling tanks!" Hark, I hear the sound of a rotating Heinlein in his grave. No spreading your genes all over the galaxy!
Crow and Morton (1955) calculated from observed distributions of progeny number in a variety of species that the effective size ranged from 0.6 to 0.85 of the census number.
That gels with what I worked out from census data - in any normal year, between 10 and 15 % of women who reach menopause have had no children (and one infers the proportions are probably similar for males ; just not recorded with confidence until recently). That's using British data from a period when homosexuality was a serious criminal offence most of the time, so it's prevalence wasn't meaningfully recorded.
Unequal numbers of the two sexes. (...) A breeding population in which there are 90 effective females but only 10 effective males has a total effective size of 36, not 100.
The grave of Lazarus Heinlein would like to add the following : [rotating noises, subterranean]. Particularly since Heinlein (through Lazarus and other characters) was a great one for lecturing the readers on the genetic consequences of breeding choices.
Fluctuation in population size. If population size varies from generation to generation, the effective number is the harmonic mean:[snip maths] Suppose, for example, that a population which normally maintains an effective size of 1000 drops for one generation to 50. Then, over a ten generation interval, Ne = 345
WW1 was not that severe, but it's generation of "doomed youth" will probably have effects for generations to come. If you put it into an "American Indian etc" or "Australian Aborigine" context of repeated generations with maybe half the population of the previous generation ... yeah, that's going to be visible for generations to come too.
Immigration of unrelated individuals into an inbred population reduces the level of inbreeding dramatically
The "isolated Swedish wolves" example, or my suggestion for distributing 100 Bowman's Embryos through a slowly growing population seeded from 14 Bowman's Wolves.
Ah, this (p6) is where he gets to the "50" part of his rule of thumb. It's to keep the inbreeding coefficient below about 1% per generation. He doesn't cite any sources for his claim that Animal breeders accept inbreeding coefficients as high as a one percent increase per generation. So someone should really check on that. I don't have a, ehemm, dog in this fight, so over to someone who cares more.
Hence, Wright suggests, the splitting of species into isolated subpopulations promotes evolutionary change
What I referred to as "allopatric speciation" above, from a palaeontological point of view.
The "500" figure for his "long term survival" Ne seems pulled pretty much from thin air with a hand-waving justification that a population that size will have reduced rates of genetic drift.
Ah - next page he gives a little more justification for "500" :
Let us ignore for the present the effects of natural selection and consider only the rates of gain and loss by mutation and drift. In very small populations, the loss of variability by sampling will be greater than the gain by mutation, and there will be a net loss of variation. Conversely, in very large populations, mutation will dominate the process, and we expect a steady gain. For each trait there will be a population size at which the rates of gain and loss are equal, and there will be no net change in the existing level of variability.
He then cites some 1976 numbers for the rate of decrease of variability in a Drosophila population to support his "500" number.
It's an argument.
Considering it involves biology (the "plus or minus 10%" science), it's got about the right number of significant digits (one). It might even be "correct". For some taxa in some environments.
Selection and linkage complicate this simple picture enormously, but I will attempt to show that even strong selection does not result in dramatic reductions of additive variance.
Tease!
Hammond (1973) collected some data which illustrate the effect of small founder populations very well. He established populations of Drosophila from one, 10 and 50 pairs, and then measured the response to selection (..) over 10 generations.
(...) realized heritability (a measure of the observed change) in populations established from 10 pairs differs very little from that in populations established from 50 [pairs]. As expected, populations founded from one pair, but not maintained at this level, showed three quarters of the maximum response
The metaphorical situation of a single pregnant human female landing on a raft on the coast of Australia and thereby founding the Aboriginal population - with the addition of, say, one further genome per generation - becomes far more reasonable than some people hold it.
Finally there is the question of whether to maintain a single large population or to split the species into a number of smaller breeding units. Such decisions will be primarily made on political or ecological grounds, but the latter course seems to have distinct genetical advantages. If a species is maintained in a number of small populations, not only is the danger of accidental extinction (for example, by disease) reduced, but an opportunity for local adaptation exists which may increase the chance of ultimate survival. Genetic drift can be countered by allowing occasional migration.
Which would be assisted, in the Jeanverse [the SF universe in which this takes place] , by the relative difficulty of moving between Petri dishes using the DAVE FTL drive. [Dangerous And Very Expensive ; Faster Than Light drive]
Well that was a very worthwhile read. Sorry for monopolising this part of the thread - I find that papers stick in my head better if I make notes on them as I'm going along.
Somehow, I suspect the Mark [author of the comic] has read this paper through several times, and it has deeply influenced his world-building.
And now that I've copied this self-conversation to my own space, I can edit the original to oblivion if requested.
Is there such a thing as a PHPBB to HTML converter? Maybe.No, not really. Oh well, it wasn't too bad.
It's time to update my data on "MOND" activity. First, the what/ why/ when.
A common plaint on the Internet is that "interesting" theories are being "suppressed" by … someone, rarely specified, for reasons eve more rarely specified. The Illuminati have an interest in suppressing techniques for running your gas-guzzler on water ; Donald Trump doesn't want the kompromat tapes that Vladimir holds to become public, whatever.
A while ago I was sufficiently irritated by this to actually look at one of the genuine scientific controversies, which greatly irks the Wingnut Fraternity - how "Big Physics" ignores alternatives to General Relativity because … no clearly-stated reasons, but it doesn't take long before someone points out that Einstein was a "cultural" Jew, and therefore a prime candidate for High Wizzzard of the Illuminati etc. etc. Which irritated me, so I decided to collect some data.
If theories are being actively suppressed, then you certainly wouldn't see papers on them being published out in, uh, public, where any YT-kook can see them (if they knew how to look, or cared to). Since most physics papers get published on "the Arχiv" before they go into their respective journals-of-publication, that's an ideal place to look. (The habit is spreading too: bioarxiv.org for the biological sciences; eartharxiv.org for the Earth sciences, and probably others in fields I'm not so familiar with.
Last year I collated the last few years of research results for a number of terms related to the ever-contentious problem of gravity &emdash; how does it relate to the structure of the universe (a lot of people don't like the counter-intuitive consequences of modern cosmology &emdash; even those who don't have particular invisible sky-fairies they want to proselytise for). That collection had some problems, which I address below, but showed that the "non-standard" theories do get some attention ; just not a lot of attention. It's almost as if the "suppression of independent thought" is profoundly inefficient, and instead not many physicists find the question (or this particular "solution" to it) to be interesting or productive. The level of interest is not greatly increasing or decreasing compared to the general changes in science publication.
Data - the Kook's enemy.
Date
Annual publication numbers for various cosmological theory terms, in Arχiv abstracts over the years.
Date
Search terms
(year-end)
Mordehai Milgrom
MOND
Non-Newtonian Gravity
MOG
dark matter
Brans-Dicke [gravity]
Mordehai Milgrom
MOND
Non-Newtonian Gravity
MOG
dark matter
Brans-Dicke [gravity]
Total 1991-09-01 to 2001-12-31
22
54
54
0
3137
251
2001-12-31
4
38
46
16
538
18
2002-12-31
2
12
13
2
576
18
2003-12-31
1
22
17
2
691
25
2004-12-31
1
12
20
2
752
30
2005-12-31
2
35
22
2
876
34
2006-12-31
2
35
27
4
895
34
2007-12-31
2
49
24
2
1053
24
2008-12-31
3
61
20
3
1199
34
2009-12-31
4
51
23
6
1443
35
2010-12-31
5
50
38
4
1306
54
2011-12-31
4
60
35
5
1475
51
2012-12-31
5
42
23
6
1543
41
2013-12-31
6
56
33
3
1602
45
2014-12-31
3
58
33
8
1700
32
2015-12-31
3
40
33
5
1864
48
2016-12-31
6
51
32
6
1799
53
2017-12-31
2
55
39
17
1889
39
2018-12-31
3
48
35
16
1993
44
2019-12-31
4
55
34
8
2128
54
2020-12-31
3
51
46
19
2149
52
2021-12-31
2
43
47
9
2180
37
2022-12-31
4
63
44
11
2320
37
2023-12-31
4
85
51
24
2369
31
2024-12-31
1
59
34
11
2582
34
Notes
The term “non-Newtonian gravity” has a problem : it collects a lot of material like “non-Newtonian rheology” where gravity gets a mention ( e.g. . non-Newtonian fluids flowing on slopes). Which is perfectly valid science (Oh, I remember having to do my drilling engineering hydraulic pressure calculations on "non-Newtonian" models, on power-law models and at least one other ; every morning at 04:30 for the 06:00 report.) So, on no better grounds than that I’m going to swap that term for “Brans-Dicke gravity”, which is a term I’ve seen before. It actually pre-dates the "MOND" concept.
The Arχiv search engine has numerous complications, and I didn’t note last year’s search terms closely. Generally I'm searching in "Abstracts" (except for Mordehai Milgrom, an "Author") ; I'm searching in the "Physics(all)" space ; other terms are covered by this search link, and substitute dates and search terms as desired. That should make it repeatable over the years. Search URL : “ https://arxiv.org/search/advanced?advanced=&terms-0-operator=AND&terms-0-term=Brans+Dicke&terms-0-field=abstract&classification-physics=y&classification-physics_archives=all&classification-include_cross_list=include&date-year=&date-filter_by=date_range&date-from_date=2018-01-01&date-to_date=2018-12-31&date-date_type=announced_date_first&abstracts=show&size=50&order=-announced_date_first ” Don't forget to strip the enclosing quotes!
The different (probably) search details this year returned 3429 “dark matter" results last year, but this years searching, on the appropriate date range, returns 2369. That’s not good repeatability. So I have to re-do at least the "dark matter" results. The other terms are numberically insignificant, and I can't be bothered to repeat the search manually. Let's see what it's like next year. Having worked out the components of that search URL, I should be able to write it into a script for … wget or cURL. But how to parse the results?
Brans-Dicke theory has a Wiki page, and has been around longer than MOND. It’s interesting that this was trending slightly upwards until 2010~2014, but has been declining since.
I’ve re-done the “dark matter” queries with this year’s search parameters. The numbers are down &emdash; I was probably getting “dark” and “matter” last time, but now should just be getting “dark matter”. Or something like that. If I was doing a formal literature search, I’d probably investigate further.
Arχiv got started in August 1991, so searches from 1991-09-01 should work.
I need to get those gridlines aligned to year-ends - every 4th year or something like that.
Last year I posted a graph of the results. Same again this year, but with some more details on the axes and header.
Results
Again, "dark matter" is far and away the most popular of these different cosmologies. The figures for "non-Newtonian gravity" remain "flat" (bearing in mind that contains a significant amount of "viscosity" related research too). "MOG" (a variety of "MOdified Gravity" theories) continues to attract a little attention. My fairly-blind choice to look at "Brans-Dicke" gravity (I recognised the name, that's pretty much all!) has turned out to be interesting : until about 2010 to 2014 it was generating more publications, but since then the number has dropped, and the trend line shows that with reasonable accuracy. Those paper numbers are higher than I think could reasonably be explained by one retirement from the field ; maybe several. This is in contrast to the continuing modest rise in publication rates on "MOND".
TLDR; version : "suppression" is ineffective. Or non-existent.
I haven't figured out what, or why, but the site somehow acquired code for setting the title (and description) to be an overlay on top of the actual content of the page. Which is bloody annoying. And I still don't know why, but eventually I've managed to get rid of the offending coding. Back to the layout I set up several years ago ("Simple Pale").
Ah-ha! - the "title behind the content" problem only happens when you've got multiple posts on the page. If you're on a single post, the problem goes away. Which is still undesirable, but I think it shows there's a problem with the template, not with my stuff. I only noticed at god-awful o'clock, when I was collecting data for the annual MOND update.
Oh, the problem of the "mail icon" in the footer getting stretched also happens when there are multiple posts on a page, but not with single posts. That looks like the same problem - and it's Blogger's not mine.
Do I still need to re-set the image width? Nope, seems to have gone away. Trying to work out where I previously broke things (the template-appended "email envelope icon" image was stretched across the page, instead of approximately square) is just ... frustrating. I don't know if it's in my code, or in it's interaction with Blogger. somewhere, their code surrounding the "email image icon" re-set the "image width" default that I'd set in a previous code block, so only that one image (in the rest of the template) got altered.
Some footling about because Blogger doesn't allow you to have "HEAD" or "BODY" tags in the post template, but doesn't say so until you try it.
The question asked above sort of answers itself. Of course Supernovae (and other "big bangs") can move anything they impinge upon. How much is maybe a more important question.
Since the ... early 1970s? isotopic data from lunar, then meteorite, samples have shown that the early solar system had been impregnated with nuclei like 26Al, which had a short half-life (7.17*10^5 years), and so a considerable energy release (per unit mass) into the materials they impregnated. Since Al is easily incorporated into silicate minerals, it got all over the place. In the early Solar system, that was a significant source of energy, probably responsible for the (seemingly) easy melting of "small" asteroids, rapid heating of larger bodies. Then it stopped, and normal service (gravitational reorganisation ; colission ; accumulation og heat from the decay of longer-lived isotopes) was resumed. OK ; not "stopped", slowed down and rapidly became insignificant. But this 26Al was a significant source of energy that was present in the early development of the Solar system, and isn't now.
The putative source of this material, and it's associated energy, is a supernova "near" to the early Solar system in it's early days. Consequences include that relatively small bodies (asteroids 4/ Vesta, 16/ Psyche ...) have obviously melted at masses considerably lower than modern Solar system compositions would suggest.
Until the detection of "daughter" isotopes of 26Al in meteorite samples (which daughters were less abundant than in terrestrial camples), this was a pizzle. The discovery of the "daughter" isotopes moved the problem to that of how big, and when, did the supernova erupt, producing the 26Al and injecting it into the pre-Solar nebula? It's very clear that it did, and the short lives of large (supernova-prone) stars makes it un-surprising. So it becomes a standard part of "planetogenesis". An early nearby supernova is accepted as a thing these decades. (If there is a dissenting opinion, I haven't heard it expressed.)
Then come the next questions : what would be the effect of such a supernova on the materials (and their arrangement) in the early Solar system? And also, what would be their effects in later stages of the Solar system? This paper concerns itself primarily with the effects of a strong interstellar wind on particles in the Solar system (which would be a necessity for implanting the above 26Al, though this paper deals with later stages up to and including today.
Essentially, the strong wind applies a "kick" impulse to the orbits of particles. The effect of the kick is strongly related to the size of the particle being considered - a particle of 10cm or larger would be unaffected, while a particle of 1mm diameter would be given sufficient impulse to be destabilised in it's orbit, if not completely ejected from the system. Orbit destabilisation would likely result in the particle accreting onto a larger body, or again, being ejected by a close encounter. The geological record contains enough medium-lifetime nuclei (specifically 60Fe
, half-life 2.6 × 106 years) to estimate a nearby supernova rate of around 2 per 10 million years, meaning that the Solar system is frequently swept clear of it's dusty components. Including Saturn's finer rings - though their regneration from colissions between the larger bodies should regenerate the dusty component on a rapid enough timescale to explain the rings we see.
Ejection from the Oort cloud of a system ndergoing a supernova is, in passing, suggested as a potential origin for bodies like 1I/ `Oumuamua (not that that body is short of origin proposals, from the sensible to the fantastical).
I checked recent results from AAVSO at about 17:30 local time.
Star
JD
Calendar Date
Magnitude
Error
Filter
Observer
T Crb
2460647.06597
2024 Dec. 02.56597
<6.0
0.1
V
HQA
T Crb
2460647.03
2024 Dec. 02.53000
9.8
-
Vis
BRG
T Crb
2460646.96597
2024 Dec. 02.46597
<5.6
-
Vis
TRIB
T Crb
2460646.45344
2024 Dec. 01.95344
11.341
0.0048
B
DEY
Inevitably, we're under 8/8ths cloud cover here.
18:10 (JD 2,460,647.26182) Not managing to get an updated measurement listing. But that's a fifth of a day ago. (0.19 JD), 4 and a bit hours. Is there a problem in the hardware?
My "Astro-COLIBRI" is reporting an "unclassified optical transient", but that's at a Dec of 31.57° N, which is … actually, that is in the right range (25~35) for the constellation. But T Corb is at dec 25.9°, so … I'm going to have to convert between RA systems.
OK,converter written, the optical transient ("AT2024addv") was only 5 degrees off in declination - which is a plausible error, but 36° off in right ascension, which is not a plusiible error. But the AAVSO website hasn't posted any more results as of 19:15. Then Firefox crashed. [SIGH]
Anything on other astronomy news sites? S&T? Nope. Astronomy.Com ? nope. CBAT ? Nope.
Has T CorB "gone"?
It looks like that was just a glitch - some blockage in AAVSO's pipeline just while the brightest magnitude readings had been posted for ages were at the top of the list. Overnight postings eventually went back to the norm of around 10 mag (Vis). Which is what you expect, but in this case we're poised for a rapid rise cataclysmic eruption.
Oh well, I got one bit of necessary stuff built into my worksheets. Now need the reverse function.
