halo around vega

[kris h]

I was using my binos last night looking at what i think is vega

so i went on stellarium and its got a double star next not that far away from the big dipper i dont know if it was my eyes or my binos

but it looked like it had a halo around it

or do i need to book a eye test

kris h

[EA2007]

eyetest

or condensation

or out of focus

or not Vega

or other

take any of the above and divide by intelligence! : )

[LukeSkywatcher]

I'd say the lenses of your bins had misted up.

[Chris H]

Either that or there was some thin high cloud creating a halo.

[brianb]

thin high cloud creating a halo.

A very frequent occurrence!

[barkis]

Info. From here.

http://chview.nova.org/solcom/stars/vega.htm

Ron.

Two Dust Disks?

In 1983, an orbiting satellite called IRAS discovered far more infrared radiation -- which has waves longer than red light -- coming from the Vega than expected for small interstellar dust grains found around young, early-type stars (<A href="http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1984Natur.307..441H&db_key=AST&high=38e0b7728716086">Harvey et al, 1984). The radiation is coming from a huge circular shell of dust surrounds the star extending outwards to 140 AU in radius, much like those that encompass Fomalhaut, Beta Pictoris, and Denebola (van der Bliek et al, 1994). The disk is thought to be made of icy dust particles that have been warmed by the star which, according toHolweger et al (1999), tends to develop after most of the surrounding nebulae of gas has been absorbed or expelled from the developing star.

(Of course this is far removed from Earths atmosphere, or Instrument induced Halo's around bright stellar objects.)

Ron.

[acey]

So there's the answer: IRAS vision!

[LukeSkywatcher]

Either that or there was some thin high cloud creating a halo.

I forgot that. Yeah Vega is bright enough as to have a halo around it caused by high thin cloud. Not many stars are bright enough to show this.

[brantuk]

Are we sure it isn't something to do with that ^£$%%^ volcano? lol

[LukeSkywatcher]

Are we sure it isn't something to do with that ^£$%%^ volcano? lol

Pretty sure not. I heard an expert on tv the other night saying that the concentration of the ash cloud above the UK and Ireland is about the same a a single grain of salt in a full bath of water.

Basically......................NOTHING TO WORRY ABOUT.

[acey]

Basically......................NOTHING TO WORRY ABOUT.

Volume of bath = 0.05 cubic metres

Diameter of Boeing 737 engine fan = 1.5m

Total cross-sectional area of air intake: 3.5 square metres.

Suppose a 737 flies through 100 miles of air with ash at the concentration of one grain per bath-tub.

Volume of air passing through engines: 563,500 cubic metres

Number of grains passing through engines: 11.27 million (5.6 million per engine).

I'd be worried!

[LukeSkywatcher]

Thanks for that acey.

Now i am worried.