What is the smallest astronomical body with a name?

Question

I'm just curious. My guess is an asteroid; I don't think something smaller would get a name.

Answer 1

Asteroid

Comets come very close behind Asteroids and in physical size they may be bigger or smaller than any given Asteroid.

Without names, the smallest astronomical "things" are gas molecules and dust. If you look at the various NASA photos of space you will find certain pics of enormous gas clouds and huge dust clouds way out in deep space that have resulted from some of the explosions of stars or possible deep space collisions.

Answer 2

maybe Ceres?....

Answer 3

Meteorites are sometimes given names, for example the Hoba West meteorite (which is in Africa).  It is large, and I'm pretty certain it is not the only one that has been given a name.  

But, in the spirit of your question, the correct answer is asteroids and some of the smaller moons in the solar system (which are asteroidlike in size).

Answer 4

Actually its probably meteoroid.

These are essentially small asteroids

http://en.wikipedia.org/wiki/Meteoroid

Answer 5

Depends what you mean by a "name"

1991 BA

This "name" uniquely identifies an asteroid.  It is 6 m is size (size of a small house).  As the name implies, it was discovered in 1991.  Not the smallest, but we need it, as its size is given as established.

2007 RS1 has an "absolute magnitude" of 30.98

while 1991 BA has an absolute magnitude of 28.667

The absolute magnitude (for asteroids) represents the brightness it would have if it were located 1 au from the sun and 1 au form Earth, with a standard illumination angle.  We can use the ratio of brightness to guess at the ratio of sizes.

30.98 - 28.667 = 2.313 magnitudes = a ratio of 8.4 times

(1991 BA is 8.4 times brighter than 2007 RS1)

Brightness is (very roughly) a function of the area, itself a function of the square of the radius (I know, asteroids this small don't really have a "radius")

square root of 8.4 = 2.9

1991 BA is 2.9 times larger than 2007 RS1

This makes 2007 RS1 roughly 2 metres across (call it 7 feet)

This is the smallest natural astronomical body with an individual designation.

(No, I should say that it is the smallest one "that I know about")

The smallest "named" asteroid I can find is 85585 Mjolnir.  It has an absolute magnitude of 21.43 (almost 800 times brighter than 1991 BA, therefore roughly 28 times bigger) implying a size of 168 metres (550 feet).

Mjolnir is the name of Thor's hammer.  Since the asteroid is a "Near Earth Object", if ever one day Thor gets fed up with us...

----

The singularity in the Big Bang theory is a state of unbound energy density.  The densest level we can "know" about is at the Planck Time.  If the universe is infinite in spatial extent now, then it was already infinite at that time.

A black hole's size is given as the radius of its event horizon.  Since we do not know how the traditional measurements (space and time) really work "inside", we do not know the real aspect of the singularity.  We assume it is a point, but...

Answer 6

The singularity is correct.  This name corresponds to the center of a black hole or the first instant of the big bang.

Answer 7

technically it would have been the singularity....