ASTRO: Barnard 335

Barnard 335/LDN 663 is a small, very dense dark nebula on the eastern
edge of the Milky Way in Aquila. It is considered to be a Bok globule.
These are usually seen in emission nebula as dark dense regions where
star formation is likely occurring. They can however occur wherever a
dense molecular cloud is found. Many of Barnard's smaller dark nebulae
are Bok globules. Bok globules are cold. One paper measures B335's
temperature as 10 Kelvin which is near absolute zero so very cold
indeed. Cold gas and dust like this is needed for star formation. If
warmer the dust and gas has too much energy to condense to form stars.
I found several distance estimates ranging from 250 to 420 parsecs (800
to 1400 light-years). You are free to flip a three sided coin on this
one. I tend toward the larger distance as the estimates were slightly
clustered to the high end of this range.

Reddish dust can be seen in areas east of B 335. Though a surprisingly
large area of the field appears rather dust free judging by the star colors.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net

Rick,

with it's warm reddish colour this dust cloud looks much cozier than it is
;-)

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

Barnard 335/LDN 663 is a small, very dense dark nebula on the eastern
edge of the Milky Way in Aquila. It is considered to be a Bok globule.
These are usually seen in emission nebula as dark dense regions where
star formation is likely occurring. They can however occur wherever a
dense molecular cloud is found. Many of Barnard's smaller dark nebulae
are Bok globules. Bok globules are cold. One paper measures B335's
temperature as 10 Kelvin which is near absolute zero so very cold
indeed. Cold gas and dust like this is needed for star formation. If
warmer the dust and gas has too much energy to condense to form stars.
I found several distance estimates ranging from 250 to 420 parsecs (800
to 1400 light-years). You are free to flip a three sided coin on this
one. I tend toward the larger distance as the estimates were slightly
clustered to the high end of this range.

Reddish dust can be seen in areas east of B 335. Though a surprisingly
large area of the field appears rather dust free judging by the star colors.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net

-10K is a bit on the chilly side! Bring out the long underwear if going
there.

Rick

On 3/10/2014 4:26 PM, Stefan Lilge wrote:
Rick,

with it's warm reddish colour this dust cloud looks much cozier than it
is ;-)

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

Barnard 335/LDN 663 is a small, very dense dark nebula on the eastern
edge of the Milky Way in Aquila. It is considered to be a Bok globule.
These are usually seen in emission nebula as dark dense regions where
star formation is likely occurring. They can however occur wherever a
dense molecular cloud is found. Many of Barnard's smaller dark nebulae
are Bok globules. Bok globules are cold. One paper measures B335's
temperature as 10 Kelvin which is near absolute zero so very cold
indeed. Cold gas and dust like this is needed for star formation. If
warmer the dust and gas has too much energy to condense to form stars.
I found several distance estimates ranging from 250 to 420 parsecs (800
to 1400 light-years). You are free to flip a three sided coin on this
one. I tend toward the larger distance as the estimates were slightly
clustered to the high end of this range.

Reddish dust can be seen in areas east of B 335. Though a surprisingly
large area of the field appears rather dust free judging by the star
colors.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick


--
Prefix is correct. Domain is arvig dot net