epsilon Aurigae B - occulting object

Hi Nikki, We know little about the eclipsing body other than what can be gleaned from timing measurements. Out-of- eclipse, it does not reveal its presences. This is why what happens during all phases of the eclipse are so very important. The contact points, ingress, totality and the morphology during it with the mid-eclipse brightening, and egress. I am working on a web page that will allow data to be entered and compared with the last eclipse. I will announce the link in the near future. Jeff Hopkins Phoenix Observatory Counting Photons phxjeff@hposoft.com

Hi Nikki,If I've understood some of the information I've read recently, I think the idea of a binary system in the centre of the occulting disk is a proposal that can help explain some aspects of the eclipse profile and also why the eclipsing object appears dark and relatively cool despite having a mass around 14 times the Sun's. I think an assumption is made that most of the mass of Epsilon Aurigae B lies not in the disc but in the object at the centre of the disk. If this were a single star, at 10 - 14 solar masses it would be so luminous that it would be obvious. The disk might not even survive under the influence of such a luminous central object (stellar wind, radiation pressure, heating?). Two smaller stars of 5 - 7 solar masses each in a binary system would have a much lower combined luminosity and so fit better with the observations and the stability of the disk. Also, I think the binary model helps explain the suggested "hole" in the centre of the disk as the two stars keep the hole clear of disk material.Hope the above is on the right track!

The disk is the one causing the eclipse. Now, how did it get there, and what is inside that hole that makes epsilon Aurigae brighter during an eclipse? I think that there are interacting stars in the center of the hole, thus making it brighter. Those stars were already orbiting the massive giant. Where did the disk come from?I think that the disk is a dust cloud, and if dust clouds come from exploding stars, then those interacting stars might have caused the dust to form a disk with their gravity, and taking the disk to orbit with them, thus eclipsing epsilon Aurigae.That's just what I think.

The current thinking about the mid-eclipse brightening is that there is an optically thin hole in the center of the eclipsing object and that object is slightly tilted so around mid-eclipse light from the F star shows through the hole.JeffHopkins Phoenix ObservatoryCounting Photonsphxjeff@hposoft.com

Interesting...but what caused the hole?

According to James Kemp,U of Oregon, there may be two B type stars in binary orbit within the hole sweeping out a transparent area.

Wouldn't that make them interacting stars?I'm new to all this.

HiAn alternative explaination for the supposed hole in the disk around the secondary of eps Aur A would be a single star having a planet that clears the dust inside its orbit (similar to Saturn's rings and their shepard moons) causing at least a gap in the dust disk.Or is this theory already out of action ?Is there any evidence that prefers one of the two possible explainations ?What could be observed to prove one of them if the secondary of eps Aur A is not observable ?CSWolfgang

Hi NikkiIts unfortunate to call the secondary component of the eps Aur A eclipsing binary 'eps Aur B' !Adding a latin letter to a star name is reserved for naming seemingly line-of-sight doubles, common proper motion pairs, and wide binaries that actually orbit each other.For the eps Aur "multiple" system, see:- WDS (Washington Visual Double Star Catalog) http://vizier.u-strasbg.fr/viz-bin/VizieR-S?WDS%2005020%2b4349 http://vizier.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=B/wds/wds... http://vizier.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=WDS/catal... CCDM (Catalog of Components of Double & Multiple stars): http://vizier.u-strasbg.fr/viz-bin/VizieR-S?CCDM%20J05020%2b4350A- HIC V1 and V2 (Hipparcos Input Catalogues): http://vizier.u-strasbg.fr/viz-bin/VizieR-6?-source=I/239/h_dm_com,h_dm_... http://vizier.u-strasbg.fr/viz-bin/VizieR-6?-source=I/196/annex1&-out.al... Notes on eps Aur in the Bright Star Catalogue (BSC, names starting with HR for Harvard Revised Number = Bright Star Number): http://vizier.u-strasbg.fr/viz-bin/VizieR-S?HR%201605 http://vizier.u-strasbg.fr/viz-bin/VizieR?-6N&-out.form=H0&//*&-source%3... the name 'eps Aur B' is actually already reserved and used for a 14 mag star located ~ 25 arcsec away from eps Aur A at position angle ~ 225°.CSWolfgang

If a planet is within that hole, then wouldn't it have been dragged by the supergiant already?Or is it because the dust has something to do with it...maybe it has it's own gravitational pull?

Hi Gravidus> Wouldn't that make them interacting stars?Not necessarily. It depends on their mass, size and distance.One usually get an interacting binary:http://en.wikipedia.org/wiki/Interacting_binary_starif one star is at least a bit heavier and therefore develops faster than the other to a giant star.If the distance between the two stars is relative close, the larger one might somewhen fill its Roche lobe:http://en.wikipedia.org/wiki/Roche_lobeand then mater can transfer from one to the other star which makes them then an interacting binary.CSWolfgang

Thank you for the help, but it is still possible, right?