Bad Astronomy and Universe Today Forum - Astronomy http://www.bautforum.com/ en Fri, 20 Nov 2009 21:44:08 GMT vBulletin 60 http://www.bautforum.com/images/misc/rss.jpg Bad Astronomy and Universe Today Forum - Astronomy http://www.bautforum.com/ Dinner for Centaurus A http://www.bautforum.com/astronomy/96949-dinner-centaurus.html Fri, 20 Nov 2009 16:43:01 GMT Just came across this image and article on the ESO site today. ESO - Dinner for Centaurus A (http://www.eso.org/gallery/v/ESOPIA/Galaxies/phot-44a-09-fullres.tif.html) ESO - Watching a Cannibal Galaxy Dine (http://www.eso.org/public/outreach/press-rel/pr-2009/pr-44-09.html) Eric Just came across this image and article on the ESO site today.

ESO - Dinner for Centaurus A

ESO - Watching a Cannibal Galaxy Dine

Eric ]]> Astronomy EricFD http://www.bautforum.com/astronomy/96949-dinner-centaurus.html Dark Flow and Dark energy considered the same coin http://www.bautforum.com/astronomy/96927-dark-flow-dark-energy-considered-same-coin.html Fri, 20 Nov 2009 02:32:08 GMT Hi all,

I'd be interested to know if anyone has thoughts on whether Dark Energy and Dark Flow are actually the same Universal Force.

Thank you.

Bebe:) ]]> Astronomy bebe7 http://www.bautforum.com/astronomy/96927-dark-flow-dark-energy-considered-same-coin.html <![CDATA[National Science Foundation's Supernova Remnants page/gallery]]> http://www.bautforum.com/astronomy/96919-national-science-foundations-supernova-remnants-page-gallery.html Fri, 20 Nov 2009 00:53:03 GMT The Gemini South Multi-Object Spectrograph (GMOS) recently captured a dramatic image of a vast cloud complex named DEM L316, located in the Large Magellanic Cloud, a nearby galaxy. The peanut-shaped nebula appears to be a single object, but the latest research indicates that it is really comprised of two distinct gas and dust clouds formed by different types of supernova explosions. http://www.nsf.gov/news/mmg/mmg_disp.cfm?med_id=65929 Enjoy team Bebe:) The Gemini South Multi-Object Spectrograph (GMOS) recently captured a dramatic image of a vast cloud complex named DEM L316, located in the Large Magellanic Cloud, a nearby galaxy. The peanut-shaped nebula appears to be a single object, but the latest research indicates that it is really comprised of two distinct gas and dust clouds formed by different types of supernova explosions.

http://www.nsf.gov/news/mmg/mmg_disp.cfm?med_id=65929

Enjoy team

Bebe:) ]]> Astronomy bebe7 http://www.bautforum.com/astronomy/96919-national-science-foundations-supernova-remnants-page-gallery.html Blast of Giant Atom Created Our Universe! http://www.bautforum.com/astronomy/96917-blast-giant-atom-created-our-universe.html Fri, 20 Nov 2009 00:35:33 GMT I thought this would be of interest to BAUT members, but wasn't sure where to put it, so here it is!

An article from the December 1932 issue of Popular Science magazine, describing the new theory from Lemaitre about our universe! This article was published only 3 years after Hubble discovered the redshift-distance relationship.

I found it interesting how little the theory has changed in some ways, and how much it has changed in others.

http://blog.modernmechanix.com/2007/...-our-universe/

The link has scanned pages and a transcript.

Quote:
OUT of a single, bursting atom came all the suns and planets of our universe!

That is the sensational theory advanced by the famous Abbe G. Lemaitre, Belgian mathematician. It has aroused the interest of astronomers throughout the world because, startling as the hypothesis is, it explains many observed and puzzling facts.
]]> Astronomy speedfreek http://www.bautforum.com/astronomy/96917-blast-giant-atom-created-our-universe.html uncertainties in stellar population syntheses http://www.bautforum.com/astronomy/96846-uncertainties-stellar-population-syntheses.html Wed, 18 Nov 2009 19:19:10 GMT Conroy and Gunn, at Princeton, list some of the trickiness of making models of stellar synthesis in galaxy formation. Some galaxies are simultaneously too red and too blue by a bit. SEE:http://arxiv.org/PS_cache/arxiv/pdf/0911/0911.3151v1.pdf Conroy and Gunn, at Princeton, list some of the trickiness of making models of stellar synthesis in galaxy formation. Some galaxies are simultaneously too red and too blue by a bit. SEE:http://arxiv.org/PS_cache/arxiv/pdf/...911.3151v1.pdf ]]> Astronomy trinitree88 http://www.bautforum.com/astronomy/96846-uncertainties-stellar-population-syntheses.html Possible Fireball Over Utah 11-18-09 http://www.bautforum.com/astronomy/96806-possible-fireball-over-utah-11-18-09-a.html Wed, 18 Nov 2009 08:03:52 GMT At about 00:15 on Nov 18, 2009 (GMT-7), I saw a bright flash out the North East window of the hotel where I work. I assumed it was lightning, or possibly a blown transformer. Conditions are clear and slightly hazy. About 10 minutes later, a woman that used to work here called to ask if I had seen the flash. She then told that her husband was working outside and saw what he described as a bright orange moon looking thing with a tail moving across the sky. Shortly after that I had someone check in who also saw it while outside. She said it was bright orange then turned a bright blue. It came over Salt Lake City (approx 40N 111.75 W) from the north and moved nearly due south. It should be noted that some people get very turned around in our lobby, so that might not be an accurate direction. I asked if she heard anything and she said she did not. Any information on this would be really nifty. At about 00:15 on Nov 18, 2009 (GMT-7), I saw a bright flash out the North East window of the hotel where I work. I assumed it was lightning, or possibly a blown transformer. Conditions are clear and slightly hazy.

About 10 minutes later, a woman that used to work here called to ask if I had seen the flash. She then told that her husband was working outside and saw what he described as a bright orange moon looking thing with a tail moving across the sky.

Shortly after that I had someone check in who also saw it while outside. She said it was bright orange then turned a bright blue. It came over Salt Lake City (approx 40N 111.75 W) from the north and moved nearly due south. It should be noted that some people get very turned around in our lobby, so that might not be an accurate direction. I asked if she heard anything and she said she did not.

Any information on this would be really nifty. ]]> Astronomy Tog_ http://www.bautforum.com/astronomy/96806-possible-fireball-over-utah-11-18-09-a.html Solar System Dynamics Small Bodies (JPL(Java)) http://www.bautforum.com/astronomy/96799-solar-system-dynamics-small-bodies-jpl-java.html Wed, 18 Nov 2009 01:23:51 GMT You guys should enjoy this, it will show the oribital dynamics within the SS http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2000OO67;orb=1;view=Far Enjoy You guys should enjoy this, it will show the oribital dynamics within the SS

http://ssd.jpl.nasa.gov/sbdb.cgi?sst...orb=1;view=Far

Enjoy ]]> Astronomy bebe7 http://www.bautforum.com/astronomy/96799-solar-system-dynamics-small-bodies-jpl-java.html Kaptain Krunch crunches some numbers http://www.bautforum.com/astronomy/96797-kaptain-krunch-crunches-some-numbers.html Wed, 18 Nov 2009 00:04:44 GMT For those of you who do lots of statistical crunching of numbers, or those of you who may have to in the future, how the stats show things is explained in detail with some very relevant WMAP examples. SEE:http://arxiv.org/PS_cache/arxiv/pdf/0911/0911.3105v1.pdf For those of you who do lots of statistical crunching of numbers, or those of you who may have to in the future, how the stats show things is explained in detail with some very relevant WMAP examples. SEE:http://arxiv.org/PS_cache/arxiv/pdf/...911.3105v1.pdf ]]> Astronomy trinitree88 http://www.bautforum.com/astronomy/96797-kaptain-krunch-crunches-some-numbers.html Spiral structure http://www.bautforum.com/astronomy/96780-spiral-structure.html Tue, 17 Nov 2009 17:16:07 GMT What do people make of
http://en.wikipedia.org/wiki/Spiral_...igned_rosettes
?

Links to papers
http://arxiv.org/pdf/0901.3503
http://arxiv.org/pdf/0911.1594

I'm hesitant about it, and thought I'd ask around for more opinions. ]]> Astronomy edde http://www.bautforum.com/astronomy/96780-spiral-structure.html Forest park in Scotland given Dark Sky honour http://www.bautforum.com/astronomy/96712-forest-park-scotland-given-dark-sky-honour.html Mon, 16 Nov 2009 09:09:28 GMT From BBC News Online

Quote:
Galloway Forest Park has been officially unveiled as the first Dark Sky Park in the UK.

The award, announced by the International Dark Sky Association, confirmed Galloway as one of the best places for stargazing in the world.

Lighting experts were brought in to ensure the skies above the forest park were pitch black at night.

The organisers of Galloway's bid said they hoped the award would boost tourism in south west Scotland.
A great first for the UK

However as always they get some minister from the government to comment on this good news and we get this wonderful gem

Quote:
Environment Minister Roseanna Cunningham said the worldwide interest in the Dark Skies initiative would put the forest park "firmly in the spotlight".
:rolleyes: ]]> Astronomy Sticks http://www.bautforum.com/astronomy/96712-forest-park-scotland-given-dark-sky-honour.html gravitational wave theory needs help http://www.bautforum.com/astronomy/96662-gravitational-wave-theory-needs-help.html Sun, 15 Nov 2009 16:24:29 GMT There are different ways of modeling gravitational waves, and depending upon how you expect them to behave, different ways of trying to detect them. Our current best money is spent on laser interferometers....giant versions of the Michelson device used to search for the "luminiferous ether" many moons ago, which ultimately led to the discovery of Special Relativity by Einstein.
Nevertheless groups try different experimental set-ups. One of the first was Joe Weber's bar type detector at U. Maryland. Piezoelectric sensors recorded distortions of a large suspended aluminum cylinder. Contemporary LIGO's should be more sensitive by far, enabling the detection of coalescing massive objects, and asymmetrical supernovae light years distant. However we don't see them yet, and theorists need some help trying to unravel the complex mathematics showing that a Weber type wave is actually a superposition of several Mathieu type waves. The proof is left as an exercise for the student. Homework, and probably a lot of gratitude from the authors. SEE:http://arxiv.org/PS_cache/arxiv/pdf/...911.2295v1.pdf ]]> Astronomy trinitree88 http://www.bautforum.com/astronomy/96662-gravitational-wave-theory-needs-help.html Did I see a Supernova http://www.bautforum.com/astronomy/96657-did-i-see-supernova.html Sun, 15 Nov 2009 13:54:01 GMT In march 2004 on clear and moonless night I remember looking out the window at work. It was around 2am in the morning. This is in Australia. I saw this star in the sky and it suddenly became very bright to almost the intensity of the brightness of a full moon. It only lasted for about few seconds, and the star was gone. Could it of been a supernova? In march 2004 on clear and moonless night I remember looking out the window at work. It was around 2am in the morning. This is in Australia.

I saw this star in the sky and it suddenly became very bright to almost the intensity of the brightness of a full moon. It only lasted for about few seconds, and the star was gone.


Could it of been a supernova? ]]> Astronomy Ammonia http://www.bautforum.com/astronomy/96657-did-i-see-supernova.html Out, Out, Cold Spot... http://www.bautforum.com/astronomy/96618-out-out-cold-spot.html Sat, 14 Nov 2009 17:18:18 GMT The authors, Granett, Szapudi,and Neyrinck, investigate the possibility that the Cold Spot ....SEE:http://en.wikipedia.org/wiki/CMB_cold_spot...in the WMAP data is due to a supervoid of low density. Although there appears to be a few low density areas at low z, they are not contiguous. At higher z, nothing appears to be a low density supervoid. SEE:http://arxiv.org/PS_cache/arxiv/pdf/0911/0911.2223v1.pdf see:http://www.solstation.com/x-objects/greatvoi.htm pete The authors, Granett, Szapudi,and Neyrinck, investigate the possibility that the Cold Spot ....SEE:http://en.wikipedia.org/wiki/CMB_cold_spot...in the WMAP data is due to a supervoid of low density. Although there appears to be a few low density areas at low z, they are not contiguous. At higher z, nothing appears to be a low density supervoid. SEE:http://arxiv.org/PS_cache/arxiv/pdf/...911.2223v1.pdf

see:http://www.solstation.com/x-objects/greatvoi.htm
pete ]]> Astronomy trinitree88 http://www.bautforum.com/astronomy/96618-out-out-cold-spot.html Origin of Solar Magnetic Field http://www.bautforum.com/astronomy/96555-origin-solar-magnetic-field.html Fri, 13 Nov 2009 14:51:26 GMT It is suggested that the thread Solar Cycle 24 be reserved for comments concerning how solar cycle 24 is progressing and related changes to the solar heliosphere.

This thread is for comments concerning what creates and changes the solar magnetic field.

In the cycle 24 thread I noted that Jack Zirker in his book Journey from the Center of the Sun, stated that solar magnetic cycle may be generated in the tachocline. i.e. Sunspots are created and rise out of the tachocline.

It appears the mainstream theory is in agreement with Jack Zicker's comments, however, there is a 2009 paper that tries to resurrect a convection zone mechanism to create the sunspots.



http://homepages.uni-tuebingen.de/ma...cospar2004.pdf


Quote:
The origin of the solar magnetic field remains a stubborn challenge of astrophysics. At the solar surface the magnetic field assumes a complex, hierarchical structure in space and time. Systematic features such as the solar cycle and the buttery diagram point to the existence of a deep-rooted large-scale predominantly toroidal magnetic field. In this review of solar dynamo theory new developments in our understanding of processes relevant for the solar dynamo are discussed. In recent years there has been significant progress with regard to tachocline physics, magnetic helicity conservation, the alpha effect, magnetic pumping, and the storage and amplification of the magnetic field. Remaining uncertainties about the nature of the deep-seated magnetic field and the alpha effect have thus far prevented the formulation of a coherent model for the solar dynamo.

Quote:
(iii) Finally, the tachocline is the best location for an oscillatory solar dynamo which is generally believed to be responsible for the solar magnetic cycle for the following Reasons: (1) Its radial and latitudinal differential rotation has the ability to produce a toroidal field by shearing a pre-existing poloidal field. (2) The α-effect, the essential mechanism for producing poloidal field from toroidal field, is usually located in the CZ but the tachocline can also produce a strong α-effect by magnetic buoyancy instability (Ferriz-Mas et al., 1994) and/or by the unstable shallow-water modes (Dikpati& Gilman, 2000a). (3) Because the tachocline (or part of it) may also be located in the slight sub-adiabatic overshoot layer, the toroidal fields can be stored for an extended period of time, and therefore can be amplified and acted on by the α-effect before they escape to the surface through buoyant rise or be disrupted completely by convective shredding.


http://arxiv.org/PS_cache/astro-ph/p.../0011367v1.pdf


Quote:
2.1 Observational and theoretical considerations

In a region roughly at the boundary of the radiative interior and the convection zone, in this paper referred to as the magnetic layer, a strong toroidal magnetic field is stored. Direct measurements of the parameters of the magnetic layer are not available, but the indirect evidence for its presence is strong and consistent. Firstly, sunspots exhibit systematic properties that point to the existence of a large-scale toroidal magnetic field that is sufficiently strong to resist being shredded by convective motions. Such a magnetic field cannot be generated within the convection zone, because it would be highly buoyant and rise to the surface too quickly to allow amplification by differential rotation (Parker, 1975). In a thin layer below the convection zone the magnetic field can be stored long enough to allow amplification up to field strengths of about 10 T. Secondly, magnetic pumping provides a mechanism by which weak magnetic fields are advected downward throughout the convection zone until they reach the top of the radiative core (Ossendrijver et al., 2002; Ziegler & Rudiger, 2003). Thirdly, the solar tachocline is also situated near the base of the convection zone, and provides a mechanism to convert a weak poloidal magnetic field into a strong toroidal magnetic field. Fourthly, computations of toroidal magnetic ux tubes rising from a stably stratified region below the convection zone towards the solar surface are able to reproduce different systematic properties of sunspots using only one free parameter, the magnetic field strength, which has to be of the order 10 T (Caligari et al., 1995).

http://arxiv.org/PS_cache/astro-ph/p.../0610703v1.pdf


Quote:
In the currently accepted scenario, the large scale solar magnetic cycle (LSSMC) is governed by a dynamo action that is the responsible for the transformation of a positively oriented poloidal magnetic field in a negatively oriented toroidal field, and the subsequent transformation of this one in another poloidal field but with the opposed polarity, and so on, until completing the cycle. The first stage of the process is the well known effect: the poloidal field lines are dragged (“frozen in”), and amplified by the differential rotation of the fluid. From early results of the helioseismology, there has been a common agreement that this process takes place in the tachocline, a thin layer (≤ 5% of the solar radii) located at the base of the solar convection zone (∼ 0.7R⊙) where the transition from a uniformly rotating regime of the radiative core to a differentially rotating regime in the convective envelope occurs. The strong radial shear (∂/∂r) that exists in this region suggests that acts mainly in the tachocline instead of in the entire convection zone.
Quote:
Ken Schatten [Solar Physics, 255, 3-38, 2009] explores the possibility of sunspots being a surface phenomenon [being the coalescence of smaller magnetic features as observations seem to indicate] and that the solar dynamo is shallow rather than operating at the tachocline, based on his Cellular Automata model of solar activity.
Quote:
Since helioseismic measurements have indicated the presence of a tachocline, i.e., an interface between a uniform and a differential rotation layer, it has been a common believe that the dynamo action takes place in this thin layer with substantial radial and latitudinal shear. Within the tachocline, a poloidal magnetic field is stretched by the solar rotation, such that a belt of strong toroidal magnetic field is formed around the solar equator (the Ω effect). Theoretical arguments suggest that this field is not homogeneous but mainly concentred in magnetic flux tubes surrounded for less magnetized plasma. In the Babcock-Leighton scenario, the strong magnetic pressure can make these flux tubes rise to the surface by the action of magnetic buoyancy to form bipolar active magnetic regions (BMR’s) in the surface. There, the poloidal field is possibly regenerated by the rise, twist and later decay of the BMR’s. Meridional circulation plays an important role in the decay and advection of this poloidal field, and seems to be the most important parameter for setting the period of the cycle (Dikpati & Charbonneau (1999)).

Quote:
The solar tachocline contains a rich variety of physics, and contributes in many ways to the workings of the solar dynamo. It includes complex quasi-equilibrium states supported by the near balances of gas and magnetic pressure gradients, gravity, magnetic curvature stresses, Coriolis and other forces. The dynamics include overshooting convection, waves of several types, hydrodynamic and MHD instabilities on several spatial and temporal scales, several types of boundary layers and dynamo action. The dynamo processes present include the in situ generation of poloidal fields by global MHD and/or magnetic buoyancy instabilities; the advection of these poloidal fields by meridional circulation; the generation of toroidal fields from shearing by the differential rotation; and storage of these fields and their subsequent eruption into the convection zone. The tachocline probably also plays a significant role in creating magnetic patterns that are seen in the photosphere. This talk will of necessity focus on a subset of these topics, including particularly global MHD instabilities and whether we can see evidence of them in surface magnetic data, meridional circulation and the boundary layers that limit it, possible jets in the tachocline, and certain solar dynamo questions. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
]]> Astronomy William http://www.bautforum.com/astronomy/96555-origin-solar-magnetic-field.html <![CDATA[NSF's New Class of Supernova]]> http://www.bautforum.com/astronomy/96522-nsfs-new-class-supernova.html Thu, 12 Nov 2009 21:01:38 GMT Enjoy team...quite intriguing.


http://www.nsf.gov/news/news_summ.js...mc_id=USNSF_51 ]]> Astronomy bebe7 http://www.bautforum.com/astronomy/96522-nsfs-new-class-supernova.html