You are currently browsing the tag archive for the ‘brown’ tag.

6299819

Between giant planets and small stars exists a bizarre class of heavenly objects known as brown dwarfs. Brown dwarfs are not massive enough to fuse hydrogen elements together as do main sequence stars like the sun, however brown dwarfs larger than 13 Jovian masses are believed to fuse deuterium atoms and large brown dwarfs (65 Jovian masses and up) are believed to fuse lithium.  Since brown dwarfs can be very much like planets or like stars, there is a specific definition to describe the objects: a brown dwarf must have experienced some sort of nuclear fusion as a result of mass and temperature, however it cannot have fused all of its lithium (or it is considered a star or stellar fragment).  A stellar physicist reading this blog might object that medium and large stars have some lithium present in their outer atmosphere, or that a very young white dwarf could still have some unused lithium present, or even that an old heavy brown dwarf could have fused all of its lithium.  That physicist would be correct: she deserves some cookies and a pat on the head for poking holes in unnecessarily simple definitions.

Various Classifications of Brown Dwarfs

Various Classifications of Brown Dwarfs

Brown dwarfs were theorized to exist in the 1960s, but no astronomer managed to discover one until 1988 when a team of University of California astronomers who were studying white dwarfs found a bizarrely cool red spectral signature for a faint companion to the star GD 165.  Since then many brown dwarfs have been discovered and sorted into the major types M, L, T, and Y.  They occupy a strange ambiguous area at the bottom of the Hertzsprung-Russell diagram—objects which are luminous and massive in comparison to everything else but tiny and dim compared to real stars.

450px-Relative_star_sizes.svg

There are some planets which are known to orbit brown dwarfs and there also brown dwarfs known to orbit true stars.  It is beginning to seem that there a great many brown dwarfs out there: perhaps they are as numerous as true stars (or maybe they are even more common than that).  Since they are hard to detect, scientists do not have a very accurate assay of their frequency in the universe.  The question bears somewhat on our understanding of the universe–since a great deal of matter is  not accounted for.

An artist's conception of a brown dwarf seem from a closely orbiting planet

An artist’s conception of a brown dwarf seem from a closely orbiting planet

My mind keeps returning to the fact that some brown dwarfs have planetary systems.  Imagine these melancholic twilight ice worlds forever orbiting a dim glow which will never blaze into a true sun.   It is a melancholy picture, but not without a certain beauty.

A Brown Dwarf with Planet and Moon (painting by Lynette Cook from fineartamerica.com)

A Brown Dwarf with Planet and Moon (painting by Lynette Cook from fineartamerica.com)

Puce flea on pale puce background

Puce flea on pale puce background

There is a lot of misunderstanding about the color puce.  The American definition is a middle tone brownish purple-pink, however, in France, where the name originated, puce describes a much darker and sterner red-brown.  Other fashion sources occasionally also use the word puce to describe a murky shade of green horror created by mixing orange and blue (although I personally regard such a concept as misguided on many levels).

A Puce Sari

A Puce Sari

The dreadful sounding name has an equally vile origin.  The French word for a flea is “une puce”.  Puce was the term used for the brownish red dried blood stains left on sheets or clothing when a person was badly bitten by fleas:  so puce has its origin in bloodstains.  I suppose we are lucky it isn’t called “crime scene” or “parasite”.  Despite the confusion regarding the nature of the color, it has had periods of real popularity.  Marie Antoinette”s favorite color was said to be puce (although I can’t find any portraits of her wearing it).  The color seems to be favored by the great and powerful–it is also the boss’ favorite color in Dilbert.

French puce suede oxfords (from "Pointer" if you must have them)

French puce suede oxfords (from “Pointer” if you must have them)

The Fulvous Whistling Duck (Dendrocygna bicolor) photo by Bob Hall

Fulvous is a color which is very prevalent in the natural world.  It is a dull mixture of yellow and brown with hints of red.   The name comes from the Latin word “fulvus” which translates as “a dull yellow-brown color with a hint of red” (sometimes etymology is easy).  Since “fulvus” is a Latin word there are a shocking number of animal species which have the color incorporated in their binomial scientific name.   There are also quite a few creatures (particularly birds) known as the fulvous such-and-such in English.  Here is a little gallery of fulvous/fulvus beasties.

Cryptocephalus (Burlinius) fulvus, photographed by Josef Dvořák

 

Pacific Golden Plover (Pluvialis fulva)

 

The common brown lemur (Eulemur fulvus) photo by Emmanuel Van Heygen

 

The Fulvus Roundleaf Bat (Hipposideros fulvus) painting by Gray, 1838

 

The Fulvous Owl (Strix fulvescens)

 

The Fulvous Forest Skimmer (Neurothemis fulvia)

 

Fulvous-breasted Woodpecker (Dendrocopos macei)

 

The tawny grisette (Amanita fulva)

 

The Fulvous Limpet (Iothia fulva)

I haven’t written about colors or about mammals for a while.  In order to brighten up your day with some endearing animal pictures, I have decided to combine the two topics by writing about the color fawn. This color is a pale yellow brown which is named for the delicate coloring of fawns (baby deer).  Actually the fawns of most species of deer have fawn-colored bellies while their backs are a darker brown with delicate white stipples.

A Fawn-colored Alpaca

The color fawn is often used to describe domestic animals such as cows, alpacas, and rabbits, however the animal which is most likely to be fawn is humankind’s best friend, the domestic dog.  Great Danes, chihuahuas, French bulldogs, boxers, and bull mastiffs are all often fawn-colored–as are an immense number of mixed-breed dogs. Some scientists speculate that the ancient wolves which were first domesticated in the depths of the ice age may have had yellowish fawn-colored coats (as do some extant sub-species of smaller southern wolves).

Pug Puppy

Mastiff Puppy

French Bulldog

Anatolian Shepherd

Great Dane

According to the stringent rules of dog-shows fawn dogs must have black muzzles, so yellow labs do not qualify.  However, judging by the photos returned when one image searches fawn dogs, it seems that many dog-fanciers are untroubled by precise use of the term.

The color fawn is also used to describe clothing.  Although today the color is not at the apogee of fashion, there were times when it was.  Since it was particularly appropriate for riding clothes, there are aristocratic eras when the color was regarded as the pinnacle of elegance and so it is not uncommon to come across 18th century portraits of foppish aristocrats wearing a veritable rainbow of fawn.

Portrait of David Garrick (Thomas Gainsborough, 1742, oil on canvas)

A Brown Creeper beautifully photographed by Tom Munson

The other day I was outside enjoying the garden when I noticed that a piece of bark was hopping up and down the fence in a peculiar spiral pattern.  When I looked more closely, I realized that it was not bark at all, but an amazingly camouflaged hunter—the brown creeper (Certhia Americana).  This tiny North American songbird lives in deciduous and conifer forests, wooded meadows, and even in towns with sufficient tree cover (like Brooklyn, apparently!).  Brown creepers range from the southwest United States up to the Canadian provinces…even up to southern Alaska, but I’ve never seen one before (or probably I have, I just never realized it was a bird).  The pattern of its feathers, which looked so random and wood-like was actually quite beautiful and subtle when the bird was seen in the real world.  I have included some professional photos because mine didn’t come out.  The brown creeper also had an endearing little pale belly.

The brown creeper's call (does anyone have a flute or a harpsichord?)

The little bird acted much like a nuthatch (of which I am greatly fond) making short rapid hops up and down the aging wood of the garden fence.  It was clearly looking for tasty insects with its sharp curved beak and I believe it caught quite a few of the pests.  Then in a flash it was gone.  I’m used to the popular songbirds or the northeast, but I have never noticed the brown creeper and I found it rather touching.  Has anyone else seen these around here (or anywhere else)?

Brown Creeper (another amazing photo--this one by John Brierley)

Ye Olde Ferrebeekeeper Archives

November 2021
M T W T F S S
1234567
891011121314
15161718192021
22232425262728
2930