Friday, 19 May 2017

Large and Small Magellanic Clouds - Real Size?

LkCa 15, Diameter if 1 light day away · Large and Small Magellanic Clouds - Real Size?

Some wiki will be cited:

The Large Magellanic Cloud (LMC) is a satellite galaxy of the Milky Way.[5] At a distance of 50 kiloparsecs (≈163,000 light-years),[2][6][7][8] the LMC is the third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (~ 16 kpc) and the putative Canis Major Dwarf Galaxy (~ 12.9 kpc, though its status as a galaxy is under dispute) lying closer to the center of the Milky Way. The LMC has a diameter of about 14,000 light-years (4.3 kpc) and a mass of approximately 10 billion Sun masses (1010 solar masses), making it roughly 1/100 as massive as the Milky Way.[3] The LMC is the fourth-largest galaxy in the Local Group, after the Andromeda Galaxy (M31), the Milky Way, and the Triangulum Galaxy (M33).

Distance 163,000 LY - 1 LD
Diameter 14,000 LY - ?

LY = 31557600 light-seconds = 365.25 light-days

Real Diameter:
14000*31557600/59535750=7420.8588957055214724 LS
=123.68098159509202454 LM
=2.06134969325153374233 LH
=14.8713415036863862262 AU (see below)


Small Magellanic Cloud, then:

The Small Magellanic Cloud (SMC), or Nebucula Minor, is a dwarf galaxy near the Milky Way.[4] It is classified as a dwarf irregular galaxy. It has a diameter of about 7,000 light-years,[3] contains several hundred million stars,[5] and has a total mass of approximately 7 billion times the mass of the Sun.[6] The SMC contains a central bar structure and it is speculated that it was once a barred spiral galaxy that was disrupted by the Milky Way to become somewhat irregular.[7] At a distance of about 200,000 light-years, it is one of the Milky Way's nearest neighbors. It is also one of the most distant objects that can be seen with the naked eye.

Distance 200,000 LY - 1 LD
Diameter 7000 LY - ?


Real Diameter
7000*31557600/73050000=3024 LS
3024/499.004=6.0600716627522024 AU

Let's quote the two other galazies mentioned as well, shall we? Here:

The Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph), also known as the Sagittarius Dwarf Elliptical Galaxy (Sgr dE or Sag DEG), is an elliptical loop-shaped satellite galaxy of the Milky Way. It consists of four globular clusters, the main cluster having been discovered in 1994. Sgr dSph is roughly 10,000 light-years in diameter, and is currently about 70,000 light-years from Earth, travelling in a polar orbit (i.e. an orbit passing over the Milky Way’s galactic poles) at a distance of about 50,000 light-years from the core of the Milky Way (about 1/3 the distance of the Large Magellanic Cloud). In its looping, spiraling path, it has passed through the plane of the Milky Way several times in the past.

Distance 70,000 LY - 1 LD
Diameter 10,000 LY - ?


Real Diameter
10000*31557600/5567500=56681.814099685675797 LS
56681.814099685675797/499.004=113.589899278734590899 AU

The Canis Major Dwarf Galaxy is classified as an irregular galaxy and is now thought to be the closest neighbouring galaxy to the Earth's location in the Milky Way, being located about 25,000 light-years away from the Solar System[2] and 42,000 light-years from the Galactic Center. It has a roughly elliptical shape and is thought to contain as many stars as the Sagittarius Dwarf Elliptical Galaxy, the previous contender for closest galaxy to our location in the Milky Way.

Doesn't say how many LY diameter, so cannot be used for showing any real size.

So, Large Magellanic Cloud, c. 15 AU, Small Magellanic Cloud c. 6 AU, Sagittarius Dwarf Spheroidal Galaxy rather larger, with 114 AU!

And Canis Major Dwarf Galaxy, I don't know.

Hans Georg Lundahl
Nanterre UL
Pope St. Celestine V

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