Meteor Between Clouds (APOD 2009 Nov 20)

[orin stepanek]

http://apod.nasa.gov/apod/ap091120.html

Awesome picture; kind of reminds me of a laser beam! 8) Are the LMC and the SMC protected from being swallowed by the Milky Way by being in orbit? When Andromeda comes calling will it probably disrupt things so that all will become part of the merger? Oh well; I won't be here anyway.

[neufer]

http://apod.nasa.gov/apod/ap091120.html

Are the LMC and the SMC protected from being swallowed by the Milky Way by being in orbit?

When Andromeda comes calling will it probably disrupt things so that all will become part of the merger?

Oh well; I won't be here anyway.

Neither will the Magellanic Clouds (like rats leaving a sinking ship):
[code]Declination Redshift
-----------------------------------------------
+41° 16′ 9″ −301 ± 1 km/s M31
-72° 49′ 43″ +158 ± 4 km/s SMC
-69° 45′ 22″ +278 ± 3 km/s LMC[/code]

<<From a viewpoint in the LMC, the Milky Way would be a spectacular sight. The galaxy's total apparent magnitude would be -2.0—over 14 times brighter than the LMC appears to us on Earth—and it would span about 36° across the sky, which is the width of over 70 full moons. Furthermore, because of the LMC's high galactic latitude, an observer there would get an oblique view of the entire galaxy, free from the interference of interstellar dust which makes studying in the Milky Way's plane difficult from Earth. The Small Magellanic Cloud would be about magnitude 0.6, substantially brighter than the LMC appears to us.>>

[orin stepanek]

According to Wikipedia:

While the LMC is often considered an irregular type galaxy (the NASA Extragalactic Database lists the Hubble sequence type as Irr/SB(s)m), the LMC contains a very prominent bar in its center, suggesting that it may have previously been a barred spiral galaxy. The LMC's irregular appearance is possibly the result of tidal interactions with both the Milky Way, and the Small Magellanic Cloud (SMC).

Sounds like the SMC and LMC already interacted with the Milky Way. So When Andromeda comes calling; there might be one big happy family. After such a merger could there probably be other satellite galaxies that are residue from all the churning that takes place. 8)

Orin

[Chris Peterson]

Quoting Wikipedia: <<From a viewpoint in the LMC, the Milky Way would be a spectacular sight. The galaxy's total apparent magnitude would be -2.0—over 14 times brighter than the LMC appears to us on Earth—and it would span about 36° across the sky, which is the width of over 70 full moons. Furthermore, because of the LMC's high galactic latitude, an observer there would get an oblique view of the entire galaxy, free from the interference of interstellar dust which makes studying in the Milky Way's plane difficult from Earth. The Small Magellanic Cloud would be about magnitude 0.6, substantially brighter than the LMC appears to us.>>

That's misleading, though. The magnitude of extended sources is calculated by integrating the intensity over the area. Some of the brightest magnitude extended objects in our sky are also amongst the visually dimmest. From the LMC, the Milky Way would resemble the Milky Way from our own viewpoint. It would not be any brighter- in fact, it would be about the same brightness as the LMC is to us... just larger.

[Case]

From the LMC, the Milky Way would resemble the Milky Way from our own viewpoint. It would not be any brighter- in fact, it would be about the same brightness as the LMC is to us... just larger.

Except that our view of the Milky Way is severely dimmed by dark dust lanes. From the LMC, one would look 'down' upon our galaxy with less obscuring dust (much like our view of M31) and also see the quite bright center much better.

[Chris Peterson]

Except that our view of the Milky Way is severely dimmed by dark dust lanes. From the LMC, one would look 'down' upon our galaxy with less obscuring dust (much like our view of M31) and also see the quite bright center much better.

Our view isn't really blocked. There are dust lanes, of course, and we see those giving structure to the Milky Way. But we see many bright zones that are not occluded by dust. I think that the Milky Way from the LMC would be less impressive than it is from our own sky. After all, M31 isn't all that impressive to the naked eye, despite being seven or eight times larger than the Moon, and exposing its core to our sight.

[orin stepanek]

Large Magellanic Cloud
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Large Magellanic Cloud

The Large Magellanic Cloud
Observation data (J2000 epoch)
Constellation Mensa/Dorado
Right ascension 05h 23m 34.5s[1]
Declination -69° 45′ 22″[1]
Redshift 278 ± 3 km/s[1]
Distance 157 kly (48.5 kpc)[2]
Type SB(s)m[1]
Apparent dimensions (V) 10.75° × 9.17°[1]
Apparent magnitude (V) 0.9[1]
Other designations
LMC, ESO 56- G 115, PGC 17223[1]
See also: Galaxy, List of galaxies
The Large Magellanic Cloud (LMC) is a nearby irregular galaxy, once thought to be a satellite of our own.[3][4] At a distance of slightly less than 50 kiloparsecs (≈160,000 light-years), the LMC is the third closest galaxy to the Milky Way, with the Sagittarius Dwarf Spheroidal (~ 16 kiloparsecs) and Canis Major Dwarf Galaxy (~ 12.9 kiloparsecs) lying closer to the center of the Milky Way. It has a mass equivalent to approximately 10 billion times the mass of our Sun (1010 solar masses), making it roughly 1/10 as massive as the Milky Way, and a diameter of about 14,000 light-years.[5] The LMC is the fourth largest galaxy in the Local Group, the first, second and third largest places being taken by Andromeda Galaxy (M31), our own Milky Way Galaxy, and the Triangulum Galaxy (M33), respectively.

I was really surprised to find out that the LMC was as large as it is. 1/10 the mass of the Milky Way is pretty impressive to me. Fourth largest in the local group; no slouch by any means! 8)

Orin