Author Topic: NGC 56- the lost galaxy  (Read 2730 times)

planetaryscience

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NGC 56- the lost galaxy
« on: November 12, 2013, 04:51:43 pm »
Pretty much everyone here has heard of the NGC catalogue, or the New General Catalogue, a huge catalog of galaxies numbering 7,840. It was compiled over many years, mainly by William Herschel. The catalog is mostly about galaxies and nebulae, but a few are stars, and even a couple are nonexistant as far as we know...

The first galaxy to not actually exist apparently is NGC 56. Here it is:



Nothing there, right? Well, they think it was just a flare from a nearby star, but I have a reason, however thin and not well-thought-out, still reason to believe there is something there, and Herschel's lost object may be found again. Before I say what I think it is, however, could you provide your opinion on the matter, and possible locations/reasons it could be?
I like to find asteroids and galaxy mergers- but all galaxies are still fine to me.

Edd

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Re: NGC 56- the lost galaxy
« Reply #1 on: November 12, 2013, 06:03:57 pm »
Candidate for an Unobject of the Day?
When I look up at the night sky and think about the billions of stars out there, I think to myself: I'm amazing. - Peter Serafinowicz

AlexandredOr

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Re: NGC 56- the lost galaxy
« Reply #2 on: November 12, 2013, 08:47:57 pm »
One of the weird things of the NGC ??
There are many others oddities, see the "Strange astronomical things" in Weird and wonderful board.
Alexandre

Baby star opening its eyes on the Universe.

graham d

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Re: NGC 56- the lost galaxy
« Reply #3 on: November 12, 2013, 09:00:28 pm »
It's certainly not uncommon to lose things. Most things are quite trivial and such a loss is no big deal. As many a woman will chortle- it was there all the time sitting in front of you. Nevertheless, I was startled. It is the first time I've heard of the loss of a galaxy, as in it was once there and has now disappeared. Of course some things aren't there if you don't look at them eg. the Moon. That's a  very large object, bigger than a fish infact but absolutely dwarfed by comparison with a galaxy. Perhaps it wasn't a big galaxy but far enough away that someone wasn't actually looking at it for a while. It's not just us; there have to be other aliens out there too. Collectively there's a finite chance that everyone wasn't looking when it was spirited away. I presume no message was left or an iou or something visible or abstract like " thanks for all the fish". A flare is highly improbable, infact infinately improbable so it could well be a well known quantum effect whereby it was swallowed by a worm hole. There's no shortage of galaxies- we find new ones every day and 1011 days is a hell of a lot of days to come. Number 56 is strangely a small number so this loss might be more common than a one off event. There are seven billion folk on the planet and I doubt there are more than a few hundred who actively look every night at galaxies. For instance who was looking at 310 say last night?

planetaryscience

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Re: NGC 56- the lost galaxy
« Reply #4 on: November 12, 2013, 10:45:57 pm »
Candidate for an Unobject of the Day?

Nice, but seriously that's a good idea!  8)

It's certainly not uncommon to lose things. Most things are quite trivial and such a loss is no big deal. As many a woman will chortle- it was there all the time sitting in front of you. Nevertheless, I was startled. It is the first time I've heard of the loss of a galaxy, as in it was once there and has now disappeared. Of course some things aren't there if you don't look at them eg. the Moon. That's a  very large object, bigger than a fish infact but absolutely dwarfed by comparison with a galaxy. Perhaps it wasn't a big galaxy but far enough away that someone wasn't actually looking at it for a while. It's not just us; there have to be other aliens out there too. Collectively there's a finite chance that everyone wasn't looking when it was spirited away. I presume no message was left or an iou or something visible or abstract like " thanks for all the fish". A flare is highly improbable, infact infinately improbable so it could well be a well known quantum effect whereby it was swallowed by a worm hole. There's no shortage of galaxies- we find new ones every day and 1011 days is a hell of a lot of days to come. Number 56 is strangely a small number so this loss might be more common than a one off event. There are seven billion folk on the planet and I doubt there are more than a few hundred who actively look every night at galaxies. For instance who was looking at 310 say last night?

Well, there are several lost NGC galaxies of which they can't seem to find a specific galaxy it was centered on, but as far as I know, NGC 53 is the first and most searched-for among them. Also, something odd about NGC 53 is that when discovered it was described as "extremely faint, extremely large, difficult." to compare what "extremely faint" would mean, he could identify late-15th magnitude galaxies just fine. To compare what "extremely large" would mean, well look

NGC 50:



NGC 52 at same zoom level:


NGC 54:



NGC 56 at same zoom level as NGC 50, 52, 54:



Nothing there, right? Well, why don't we zoom out a bit



Oh, look! A galaxy! It appears pretty faint though.
Look:

Seems a bit small for "extremely large", and at magnitude 15.3, it is not exactly "extremely faint," so it probably isn't it. What about the neighborhood around it, though?


A big galaxy to the lower left! What is it?

PGC 1,107, Wikisky claims.



Also, 'extremely large' as Herschel says!
The magnitude of the center is 16.9, a bit too faint to be considered "extremely faint", but of course that may be a bit off. This galaxy may be NGC 56, and according to NED, its distance from us is 52,000,000 light years, a lot like the other galaxies in the NGC catalog, even to be considered part of our local cluster. This means that it's possible that the galaxy used to be brighter, and possibly a lot brighter at the time of Herschel because it's so close, and even a small change in distance amounts up to the galaxy moving 858,816,000,000 away, or about 0.090776923 light years. :-/ Anyways, could this be Herschel's lost galaxy?
I like to find asteroids and galaxy mergers- but all galaxies are still fine to me.

graham d

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Re: NGC 56- the lost galaxy
« Reply #5 on: November 16, 2013, 10:00:39 am »
 Andrew over on "Dispatches from Turtle Island" http://dispatchesfromturtleisland.blogspot.co.uk/2013/11/a-lost-and-found-galaxy.html has recently cited this thread.
Perhaps William drank too much Hermitage that night? Who knows?

In a more serious frame of mind we need to consider what we mean by our local place in the universe. Galaxies occur in groups, clusters and superclusters separated by space. If one googles these key words and searches images there are a plethora of examples that reveal the universe's structure. http://commons.wikimedia.org/wiki/File:Local_galaxy_filaments.gif or view galaxy filaments.
 A more technical discussion lecture 25 is here http://ircamera.as.arizona.edu/astr_250/Lectures/Lec_25sml.htm

What are galactic filaments or walls or sheets etc? Well they are morphological descriptions of what we observe- all those countless google images. I mentioned some while ago that I could see many triple junctions out there, similar to what one sees in a can of oil as it slowly warms up or global plate triple junctions as we see here on Earth. Of course I am biased, those on Earth have a failed arm, otherwise the Earth's volume would increase without limit. Again, the global plates are essentially two dimensional structures whereas in the celestial vault the galactic motions of filaments take place in a three dimensional space. At increasing distance we still see filaments but the basic units we observe or galaxies become increasingly structureless "irregular blobs" which if in close association suggests that they are merging. As we go to increasing distance we see earlier epochs(times) in the history of the universe.
Is the universe isotropic and or homogeneous and do we live at a priveleged time and position? These encompass what are referred back to as a simple cosmological principle and the Copernican viewpoint. Within the local group of our own galaxy were one to look around from the locale within a large globular or spherical starcluster within a galaxy the night sky would appear totally different than we we to change locale to the barycentre of our local group or let us say midway between Andromeda and the Milky Way. One wouldn't see any stars in the night sky and with my eyesight I might see a faint haze that would represent the core of Andromeda, about fourfold brighter than from our Earthly vantage point. Again, on the other side of the sky our Milky Way would display only a slight haze. Without a telescope to enhance our vision we wouldn't even debate the priciples central to astronomy.

Our local group is confined to a size or diameter of several million light years. Out at 52 million light years NGC 1107 probably belongs to the Virgo cluster. Is it gravitationally bound to that rather than our own local group? It doesn't really matter in that our local group is certainly bound to bigger fish. Galaxies or rather clusters of them do recede in an expanding space, the Hubble expansion and it appears incontrovertible. I see no reason to challenge that statement, that space is expanding as per lecture 25 and similar presentations.

Cosmic density or the critical density= 3*Ho2/8*Pi*G is actually a limit. There's a straightforward derivation. One has to balance gravitational potential and kinetic energies of the total energy of the system. As one goes to greater radial distance things look more symmetric, ideal spheres with volume 4/3 *Pi*R3 and mass this factor fold cosmic critical density. The system has kinetic energy and this is related to 1/2 Ho2* R2. The kinetic energy also includes angular momentum that needs to be released, ultimately as heat to the voids which I do not address. No matter how irregular galaxies and ancient blobs may be, ie. I mean hugely distorted from a spherical form we need a proof to demonstrate at what R that irregular blob might collapse, a consequence of sufficient mass to be either gravitationally bound or not ie. sufficient kinetic energy to fly away to infinity. These blobs are what you observe. In this case by they represent filaments of galaxies rather than ancestral galaxy blobs that are globular or irregular, that appear to be merging. The Abell supercluster is relatively close by. By that I mean one can see an association that is irregular and elongate. It is not ideally spherical. Nevertheless draw a circle that encompasses the longest axis. The gravitational potential on the surface of this sphere is idealised as uniform and lower than what would be measured were one to measure the potential at various points along an irregular shape in proximity to the elongated blobs of galaxies.

What we observe, what I observe infact as filaments appear to be strings or ropes of galaxies with triple junctions. Of course I am biased about triple junctions, there are often four or five and in fact occasionally one observes what looks very spherical , a triple spherical cow of a junction that is representative of that famous formula for critical density with the numerical factor 3/(8*Pi). Ultimately, it comes from the first few lines of the derivation with factor 4/3* Pi *R3. 8*Pi* G is a famous factor. It is fallacious in that it doesn't approximate what we actually observe. There's no problem with Ho- it is empirical fact

Yet what we observe are filaments, however you so define them they are not the 4/3 Pi volume sort. As ropes or strings they are R* (Pi*R/n)2 volumes where R/n is the ratio of idealised R to rope radius. Now they are not long single ropes, they don't look like single ropes. Many are biforcated and are so becaused I am actually biased about triple junctions. You may see four junctions or more or even object that these aren't rope stuctures at all because they can be described as sheets or walls. Well! calculate the gravitational potentials along these sheets; you do need to address volume and eventually derive a critical density for homogenised mass . You will find  critical densities that lies between the 3Ho2/8*Pi*G , as a limit for for the universally accepted derivation that assumes spherical cows all on up, and irregular turtle densities all on down, to the limit of Y triple junctions or

critical density based upon filaments of Pi2/6 *Ho2/G

An actual averaged out cosmic density is between these limits but it doesn't exist, there's no privileged average density.

What does it mean? One could devote a whole chapter to an alternative derivation of critical density ? with numerical factors 3/8*Pi versus Pi2/6 . Consider a sphere of galaxies where R becomes big enough to encompass... but hardly big enough to encompass the whole universe. The critical density homogenises the distribution of matter, it's idealised and extrapolated wholescale to well beyond z=2. We see out to say z=10 and to an earlier phase where irregular blobs become apparent, "obviously merging". I make no assumptions here, I describe what I see rather than infer a merging or evaporation. It's a filamentous structure of galaxies we observe along with great voids. Neglecting angular momentum which will dissipate eventually, if I inscribe a sphere around any irregular glob with the major axis incorporated therein; if there is sufficient mass within rather than inferred critical density it will collapse all the way to a black hole. The density depends upon the geometry idealised. The blobs have kinetic energy, sufficient of course to prevent collapse.

The idealised density imagines a volume big enough to describe homogenised matter and isotropic. It is expanding, the system has an entropy and it is increasing. The filamentous organistion of matter as galactic units actually has a higher entropy and as expansion occurs it will also increases but it always higher than the idealised spherical system at any time. Unlike the chemical systems in thermodynamics , agglomeration of matter gravitationally packs entropy ultimately into black holes. A filamentous structure of galaxies at its simplest appears a more likely, a more probable configuration in the evolution of structure. It works in a bath of oil , here on Earth with plate tectonics although how useful these analogies really are I do not know. Yet the newly derived critical density is huge! It's more by a factor of ten from the idealised sherical cow calculation. It depends upon how many triple junctions there are; some may prefer interconnecting membranes or more rigorous mathematical treatments. Then again it varies from region to region. Imagine if you were an observer in a large void? Well with a big enough telescope an external observer would eventually realise major scientific progress unless they were aquatics or in a save haven totally albeit shrouded in clouds of whatever- ammonia! 3/8*Pi is famous for physicists but so also is Pi2/6 to a chemist and mathematician, infact so also a physicist. I quote it as a limit for biforcated strings, for idealised triple junction filaments. The universe appears less isotropic and less homogenous than assumed. That's a vague association and so also so are these astronomical principles. The older I get the more privileged I feel, another triumph for Pi2/6 applications. Don't take my word for it, check it yourself.






 
« Last Edit: November 16, 2013, 12:36:20 pm by graham d »

graham d

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Re: NGC 56- the lost galaxy
« Reply #6 on: November 16, 2013, 04:58:09 pm »
Oops I made at least one gaff. I did mention years ago the intention to report, obviously in haste, how an idea can be crystalised as it happens. Obviously, one should put it in the drawer and muse the following days. But that's not how it happens much of the time and I promised to discuss things, flaws, warts and all.  The factor is 6/Pi2, so it's 5.1 fold the critical density based upon the idealised spherical symmetry. Also we are talking about the three simple parameters as the bedrock of matter, or rather mass energy density , rho critical, Ho , (Ht is derived not measured) and Ho is empirically determined to maybe ~7% accuracy or better if you accept the high precision claims, about 71 km/second per every megaparsec ( 3.26 million light years) one travels. Big G I accept as a constant despite doubts. So out at ~52 million light years approaching Virgo we have stepped away some 52/3.36 or let's say 15 increments of 71km/second , circa 1000km/second which is circa greater than any local velocities within galaxies and the data plots, unlike those for Hubble, do start to fall upon the linear v=H*R plot. It's a remarkably simple relation infact. At the cluster level the galactic groups do move away, but not isotropically, but vectored along filaments. The voids are essentially empty. Perhaps there are lost stars there?

For Einstein empty space was empty. He was attempting to unify gravity and that part of the weak force that is electromagnetism. Take out all the matter and I guess the radiation or photons and it was nothing. Now matter and space for him were closely related, matter's effect on space and space's geometry on matter, Wheeler's famous ditty. Remove matter and radiation and we are left with nothing, not just empty but the void or "vessel" itself. The particle physicist and the condensed matter ones wouldn't accept that with good reason. Instead as an embarassment, the vacuum energy is a colossally huge density of virtual particles. The Higgs field remember now fills that empty vessel and other hidden fields too. It doesn't amount to much but the real mass energy is at least photons and restmass neutrinos of ca. 1 electron of mass equivalent occupying each cubic metre of the void as well, but it is tiny compared to the accepted critical density. The accepted critical density numerical factor 3/8*Pi is obtained by comminuting all known matter stuff and averaging it out into those huge volume voids that are supposed to be empty, as well as within filaments where it underestimates actual density. This is all well known and obvious. We go out to large enough radius and irrespective of distribution we can sum all mass and localise it at a centre as per Newton. We calculate the potential energy of our test particle or galaxy moving at this surface and the critical density is as predicted for the 3/8*Pi factor. Yet if we could measure it the potential energy is much lower along the filament surfaces and it's along these filaments that we measure Ho. There's nothing in the voids apart from the supposed fact that they expand, space is relative, time is relative and so also according to Einstein, spacetime is relative. The alternative is increasingly longer wavelength and lower energy relic photons and rapidly diluting relic restmass neutrinos inhabit the voids. No new matter is envisaged as created in the voids or anywhere as it is inconveniently related to a defunct theory. Should those photons and neutrinos not prove to be relic but new mass energy in a non superluminal void, a lot of folk will be long on embarassment.

Instead we have recessional velocities that are superluminal at low z in the progression back to huge z (~1100). The void or Einstein's nothingness can attain superluminal velocities but matter stuff in it obviously cannot. Eventually, everything dilutes to nothing. Not so- dark energy comes to the rescue and replaces the currently accepted critical density mass energy by itself. Eventually is a long time ahead, far far greater than our current timescale of 14 Giga year. Hence, we are privileged to exist within this first timeslice of ~1010 year rather than at times within the >1024 timeslices of equal periods yet to come. Why 1024 timeslices? There's a new non Susy SO(10) model just out that predicts proton instability in the new improved range >1034years justifying future HEP expenditure! We are easing ourselves, and it's still fashionable to publish  so within accredited journals, into disciplines that are close to metaphysics and anthropism. Enough said today.
« Last Edit: November 16, 2013, 05:11:06 pm by graham d »