Labelling Astronomical Objects

The direction of objects in the sky is determined by two angles, declination and right ascension. If we imagine all the objects projected onto the surface of a sphere ("the celestial sphere") then these two angles are analogous to latitude and longitude, which determine position on the Earth's surface. The celestial sphere is divided into constellations ("con-stellations"), which are analogous to countries on the Earth. Constellations contain prominent groupings of stars such as the Great Bear (Ursa Major) or Orion; these stars may have no real dynamical connection with one another, in that their distances from us may differ enormously.

Within constellations, objects are labelled with a Greek letter [alpha, beta...] roughly according to their brightness, and for fainter objects, by a number 1, 2,... . Thus " 61 Cygni" means "Object number 61 in the constellation Cygnus (the swan)". Galaxies, and other objects of non-stellar appearance such as nebulae (gas clouds) within our own galaxy, have a separate nomenclauture: thus the closest galaxy to ours, in the constellation of Andromeda is "M31" -- the 31st object in the old catalogue of Messier -- or, alternatively, "NGC224" -- the 224th object in the New General Catalogue. In the catalogues all these objects are of course precisely located by their "map reference", that is, by their right ascension and declination.

Principles of Cosmology and Gravitation, Appendix A. By M.V. Berry, Institute of Physics Publishing, Bristol and Philadelphia, 1993.

In a nutshell, if you are a user of the popular "Thomas Guides" available, at the very least, here on the west coast of the USA, when you go to find out where Buttonwillow, California, is, you look up in your Thomas Guide the page and grid location -- say, 224 E-5 -- and flip to page 224 and look where the rows and columns E and 5 intersect. Now you know where Buttonwillow is. If you were looking for the Lesser Magellenic Cloud, you'd look in your New General Catalogue to find the right ascension and declination, after which point you could identify the LMC on any photo that has right ascension and declination marked on it. Row, column, intersect on the pretty picture.

Just be glad the next Shell station isn't "one galaxy over".

Monkey On My Back

Hi, my name's Sidra, and I'm newly addicted to spinning yarn.

I'm so new to it I still SUCK ROCKS THROUGH SWIZZLE STICKS, but it's like crack -- one hit and you're toast, standing in the middle of the local crafts store asking people if they can hook you up, man.

It's like this -- you take this fluffy hair that came off a sheep/llama/rabbit/goat and a stick with a weight at one end and then --

LOOK!

twist twist twist

You have a single strand of yarn.

Fluff....yarn. Do it again!

Fluff...yarn. Oh my god, that's a strand of yarn. Do it again!

Fluff...yarn. Wow!

and so on, and so forth. You see?

"Hi, everyone, my name's Sidra, and I'm an addict."

"Hi, Sidra!"

Culture, Ahoy!

I got cultured™ this weekend. (so, now I'm yogurt, is that it?)

My folks came down to visit and we went to the San Diego Museum of Art. We had the good fortune to run into a Renoir [and related styles] exhibition, and each of us fell in love with several different paintings [oddly, often side-by-side] . My dad and I both fell for Renoir's The Letter, and we both loved a couple other portraits. Stupid me, not having a way to take notes at the time. One was Griselda, the other...Mrs. Clark-something.

There was a South Asian art display in one of the smaller upstairs galleries [Shiva, Destroyer of Time], and another much larger Asian art display that we did not see all of -- mostly statuary [Buddhas, Bodhisattvas, primarily] from Thailand, China [I think] and Cambodia, and some beautiful prints from Japan. One of the prints made Janis and myself share a laugh -- tamano-no-mae revealing herself and becoming a fox, which we looked at literally seconds after remarking on Yoshitaka Amano's illustrations in Neil Gaiman's The Dream Hunters.

Overall I had 2 or three favorites in every gallery we stepped into, which was over 15. I like portraiture and still lifes and my favorite artist is probably Jan Vermeer [Johannes Van der Meer], simply for the light [simply! she said, of course for the light!], but I adore Chinese and Japanese art.

One thing that was fascinating was a restored painting of David with the Head of Goliath. It's a very vibrant yet dark painting by Massimo Stanzione that appears to have been partially painted over at a later date to remove the head. The truly intriguing thing about the restored work was the photo series displaying the modified version, an x-ray where the head is visible, and other steps along the way to complete restoration. Very, very neat.

Latest Book Review

The Tending Instinct: How Nurturing is Essential to Who We Are and How We Live,

by Shelley E. Taylor, 2002.

review by moi. Read now.