# Are LMC, SMC approaching the Milky Way ?

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1. Dec 27, 2009

### Widdekind

Are LMC, SMC approaching the Milky Way ??

Are the LMC & SMC approaching towards, or receding from, the MWG ?

According to my calculations, using the data from here, and accounting for a ~220 km / sec velocity of the Sun, towards galactic longitude b=90 degrees, the LMC is moving nearly 40km/sec, towards b=90 degrees, in the rest frame of the MWG, while the SMC is moving nearly +100km/sec in the same said direction.

If the calculations are correct, both the LMC & SMC seem to be moving towards the MWG. But is this correct?

2. Dec 27, 2009

### Astronuc

Staff Emeritus
Re: Are LMC, SMC approaching the Milky Way ??

According to http://www.maa.clell.de/Messier/E/Xtra/NGC/lmc.html
"Both Magellanic Clouds are irregular dwarf galaxies orbiting our Milky Way galaxy, and thus are members of our Local Group of galaxies."

There are closer galaxies - http://www.maa.clell.de/Messier/E/More/cma_dw.html and http://www.maa.clell.de/Messier/E/More/sagdeg.html

Apparently the Andromeda galaxy is moving toward MWG. "The modern values for Galactic rotation and heliocentric radial velocity yield that the Andromeda Galaxy and the Milky Way are approaching each other at about 100 km/sec."
http://www.seds.org/messier/m/m031.html [Broken]

http://www.seds.org/messier/more/local.html [Broken]

Apparently there is new information on the LMC and SMC. They may not be as bound to the MWG as previously thought.
http://www.cfa.harvard.edu/oir/eg/lmc.html
http://arxiv.org/abs/astro-ph/0508457

Last edited by a moderator: May 4, 2017
3. Dec 27, 2009

### Widdekind

Re: Are LMC, SMC approaching the Milky Way ??

Thanks for the response & refs !