The Birth of a Star ????

"G=EMC^2 Glazier" wrote in message
...
BV It is bad thinking because if stars are being created continually at
a rate to keep stars in our galaxy at 200 billion we should see some
stars(new ones) come into view from time to time no matter how long the
fusion time takes. Its all relative to time and the number of stars
created. If it takes a billion years to create a star,and a billion
stars are created in that spacetime than we should see one star created
on average each year. Simple math,and realistic thinking. However don't
flame me if this comes under the uncertainty principle. I realize some
stars take longer or shorter depending on their density area of the
nebular,and a space shock wave. Bert


What, then, is the criteria for determining that a star that we see is NOT
in it's "flare up" stage. We see plenty of proto stars in nebulae, and we
see plenty of small dim stars in nebulae. How do you know that not one of
them is in the birthing phase? Could it not be conceivable that many of the
stars we see imbeded in nebulae are becoming brighter, although it takes
more than a human lifetime to observe any significant change?

Hap Griffin

G=EMC^2 Glazier wrote:
David A new star would eventually have to come into view(yes) In the
milky Way there are 200 billion stars that are in view. They did not
all come into view all at once. Each one had a long spacetime of being
compressed by gravity to a temperature,and pressure to create fusion,and
radiate photons. This is still said to be a continual process,and yet
we have never detected a new star coming into view. Could the answer be
that todays nebular is not as dense? That makes sense,our galaxy is
middle age(so I read) No supernova going off in the Milk Way to send
the needed shock wave. David it would take a long time
to create a galaxy with 200 billion stars,but it makes sense we should
see one come into view. The earth is also located in the best viewing
area of star formation in the galaxy. I would like to see one new star
in my life time I don't think that is asking to much with 200 billion
out there already. Bert


Lets try this again. Stars form in clouds of gas and dust. Dust shrouds many
of these regions in particular, preventing us from seeing far in in visible
wavelengths. We have been looking using visible wavelengths and telescopes for
almost 400 years. We have been able to exploit infrared wavelengths since the
space age, putting IR scopes above the IR-obscuring water vapor and carbon
dioxide in our atmosphere. So, for 1/10 of the time we have been looking with
visible light telescopes we have been had access to IR wavelengths.

Now, add to this that IR is used to study a variety of things in the galaxy and
universe. All compete for time with the orbiting IR scopes. The IR scopes also
have finite lifetimes (coolant runs out, for example). Thus the chances of
looking at the right place at the right time when a star finally turns on and
finally gets rid of its dust cocoon are quite slim.

Finally, none of these star producing clouds are very close to us (the Omega
nebula is some 5500 lightyears from us, the Horsehead is some 1600 ly away, the
Orion nebula is some 1500 lightyears away. For a star to appear bright enough
to see with the unaided eye (say 4th magnitude, taking moderate light pollution
into account), and if it was in the Orion nebula, its absolute magnitude would
have to be about -4.3. This is a star over 4000 times more luminous than the
Sun. These stars are rare in formation compared to low mass stars. But, more
to the point, since the requirement was to be able to barely see it, do you
think you would notice when looking at a star filled sky?

What if we really made it noticeable - 1st magnitude. Not a lot of those in the
sky so a new one might stand out. This would be a star with absolute magnitude
of -7.3 corresponding to a luminosity of roughly 67k that of the Sun. These are
even rarer in number than the vast number of stars in our galaxy. And, it would
still have to outshine the gas cloud it is within, generally emission nebula
with dust and gas that can be between us and it (meaning it would really have to
be even more luminous to counteract the loss of light due to the dust, let alone
the distance).

So, what it boils down to is what others have said. Because of the obscuration
by dust in the nebula in which new stars are forming, because of the type of
radiation emitted by these nebula surrounding these new stars not being visible
but infrared, because there are no star forming regions near us, because of the
time it takes to have a pocket of gas collapse and form a star to begin with,
and because no one IR telescope is solely positioned to monitor every heat
source in one of these clouds in hopes that one of them will break free while we
are watching, the probability of seeing any one star turn on is small.

Hi Scott Thank you for putting a lot of time (words) in your post. I
liked the last word the best "small" Small chance has to be very true
for not one new star has come into view not in recorded time. I find
that very interesting. If I had not read it in the astronomy books I
would find it hard to believe. Are there theories on this? I posted
less dense nebular and much fewer supernova explosions. Having less
nebular (clouds) makes space transparent. Do the dust
particles inside nebular make them visible? How hot is the nebular? Are
nebular in lock step with the stars? We do see stars in the nebular,but
I think they might not be inside the cloud,but in back of it. Still
that can tell us something. Are nebular rotating? they must be.
Bert

"G=EMC^2 Glazier" wrote in message
...
BV It is bad thinking because if stars are being created continually at
a rate to keep stars in our galaxy at 200 billion we should see some
stars(new ones) come into view from time to time no matter how long the
fusion time takes. Its all relative to time and the number of stars
created. If it takes a billion years to create a star,and a billion
stars are created in that spacetime than we should see one star created
on average each year. Simple math,and realistic thinking. However don't
flame me if this comes under the uncertainty principle. I realize some
stars take longer or shorter depending on their density area of the
nebular,and a space shock wave. Bert

OK, so you believe my thinking is bad. What is your thinking? Why are we not
'seeing' stars born every day?

BV.

Because he totaly FAILS to understand anything dealing with Astronomy, like the
FACT that many of the birth places for stars are very far away and most of the
time ( 99.9% ) the stars are withing the dust clouds and if we can see them at
all it's only after their stellar winds have blown away the dust, but many of
them are behind the dust clounds ( look at the Eagle Neb.photos) and we only
know they are there because some of their light makes the edges of the cloud
glow. Just think, at one time our own sun was in such a place, but in the 12 or
more orbits of the milkyway we've long moved away from where ever it was the sun
was born in.

Plus he fails to get it into his mind that we have to talk in terms of BILLIONS
of years, and if you look at it on that scale, the chance of an astronomer
looking up some night and seeing the first light from a new star, well I'd not
want to BET on it happening! Got a better chance of seeing a Super Nova.


--
"In this universe the night was falling,the shadows were lengthening
towards an east that would not know another dawn.
But elsewhere the stars were still young and the light of morning
lingered: and along the path he once had followed, man would one day go
again."

Arthur C. Clarke, The City & The Stars

SIAR
www.starlords.org
Bishop's Car Fund
http://www.bishopcarfund.Netfirms.com/
Freelance Writers Shop
http://www.freelancewrittersshop.netfirms.com
Telescope Buyers FAQ
http://home.inreach.com/starlord

"BenignVanilla" wrote in message
...

BV I posted my theory on this. The two main reasons. Mass density of
nebular to low,and no close by supernova explosions. It all comes under
mass density(particles) that gravity has to work with. The universe is
thinning out locally,and expanding on a large scale proportional to the
greater the distance from the Milky Way. All good reasons for star burst
spacetime as just about over in our corner of the universe. Bert

"G=EMC^2 Glazier" wrote in message
...
BV I posted my theory on this. The two main reasons. Mass density of
nebular to low,and no close by supernova explosions. It all comes under
mass density(particles) that gravity has to work with. The universe is
thinning out locally,and expanding on a large scale proportional to the
greater the distance from the Milky Way. All good reasons for star burst
spacetime as just about over in our corner of the universe. Bert


So if the Universe is thinning out locally, wouldn't my post make some
sense? If the Universe is thinning locally, there would be less opportunity
to see a birth? Maybe the births are happening very far away. BTW, Bert, I
hope you recognize I am engaging in a conversation and not arguing right or
wrong. I am honestly conversing here.

BV.

BV I find that refreshing,and a change for the better. Bert