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If Brown Isn't a Color, What Color are Brown Dwarfs?
Written by Fraser Cain
Artist's impression of a brown dwarf. Image credit: NASA/JPL
We've talked about brown dwarfs here on Universe Today for years and
years. These are the "failed stars"; objects with too little mass to
fully ignite nuclear fusion in their cores. Instead of blazing with
red, yellow or the white light of our own stars, they're heated by the
gravitational collapse of material. They're called brown dwarfs, but
you might be surprised to know that they aren't actually brown. In
fact, it's impossible to have brown light. So what color are they?
The term "brown dwarf" was originally coined by Jill Tarter in 1975 to
describe these objects, and there were other suggestions for names,
like planetar and substar. But the name "brown dwarf" stuck. And here's
the problem, as described by Jill Tarter, "it was obvious that we
needed a color to describe these dwarfs that was between red and black.
I proposed brown and Joe (Silk) objected that brown was not a color."
Brown isn't a color?!
Not for astronomers. When they consider the color of a star,
astronomers are talking about the wavelength of the light being
emitted. Stars emit light at various wavelengths, and whatever photons
are mostly being emitted are what we see. Yellow stars emit primarily
yellow photons, red stars emit mostly red photons, etc. But you can't
have a star emit brown photons because the "color" brown is a
de-saturated yellow. And there are no mixtures of photons that can
produce light that looks brown to our eyes. Brown dwarfs can't be brown
because it's impossible to emit brown light. So what color are they?
Dr. Kenneth Brecher is a professor at Boston University and the primary investigator for Project LITE.
This is a research project that uses a variety of experiments to
understand how people see color. I highly recommend you check out the
Project LITE website and take a look at the Flash experiments they have
available. You've probably seen some of these optical illusions in the
past, where spinning wheels of black-and-white can actually create
different colors in our brains. Brecher demonstrated one of these color
wheels for me - it's a CD that can spin like a top. At rest, you see
black-and-white, and then spin up the disk and you can see red, green
and blue. Very cool stuff (totally unconnected from the color of brown
dwarfs).
wn dwarfs).
The color of a brown dwarf
Brecher did a presentation at the American Astronomical Society Meeting
about the actual color of brown dwarfs. He even had a flashlight that
shines a light the color of brown dwarfs. Unfortunately, I didn't catch
a photo of it, but check out Nature's blog, they got one.
It's sort of a dull orange color. But here's the cool part. There's no
way to actually see the color of a brown dwarf unless you're having the
photons strike your eyeballs.
All you color theory folks might want to know the hexidecimal code: EB4B25. And here are the RGB values: R-235, G-75, B-37
So what color would an isolated brown dwarf look like? Dr. Brecher
had a slide in his presentation that shows the color - we've extracted
it and made it bigger. I think it looks kind of reddish orange, but
then color is in the eye of the beholder.
So what color would an isolated brown dwarf look like? Dr. Brecher
had a slide in his presentation that shows the color - we've extracted
it and made it bigger. I think it looks kind of reddish orange, but
then color is in the eye of the beholder.
https://www.universetoday.com/2009/01/06/if-brown-isnt-a-color-what-color-are-brown-dwarfs/#more-23247
Mystery: Brown Pelicans Dying Along California Coast
A disproportionate amount of Brown Pelicans have been dying
along the California coast in recent days. This is especially troubling
since the pelicans have been on the endangered list since 1970. The
birds were nearly decimated before the chemical pesticide DDT was
banned in 1972.
This grim development is being monitored by wildlife conservation and rescue groups including WildRescue, operated by Rebecca Dmytryk.
According to Dmytryk, more than 50 dead adult brown pelicans have been recovered along the California
coast and more than 60 ill or dying pelicans have been rescued inrecent days. She fears those numbers may increase dramatically as more
birds are discovered.
From freeways to backyards
– more and more birds are turning up where they don’t belong,disoriented and dying. The birds are normally found on beaches, wharfs,
and harbors.
Domoic acid, a neurotoxin which has plagued the species in the past
,has been known to cause similarly disorienting behavior. What is so
baffling and troubling to experts about the current turn of events is
that regular testing of coastal waters has not revealed any unusual
amounts of domoic acid. The birds ingest such toxins via the fish they
eat, which have in turn absorbed them from the water.
Since the DDT pesticide ban, Brown Pelicans have improved in number
to the point where they are being considered for delisting from
endangered status. They are, however, still considered endangered and
the current situation is very disturbing to wildlife experts who don’t
yet know the cause of this massive and sudden event. Speculation as to
the cause ranges from a possible chemical spill to exposure to toxins
as a result of water runoff from the California wildfires.
Testing is currently underway to determine what is responsible for
the deaths. Blood samples are being examined carefully in a frantic
effort to unravel the mystery of the dying birds.
The U.S. Fish & Wildlife Service describes the adult brown pelican as a large dark gray-brown water bird
with white around the head and neck. Younger birds are described as
gray-brown above and on the neck, with white underneath.
If you live in California and you find a dead or ailing pelican, please call WildRescue at (866) WILD-911.
Image Credit: ChuckThePhotographer at flickr under a Creative Commons License.
Not aware or heard about the brown dwarfs.
But the Pelicans is a sad state there.
Someone out there are doing something illegal.
Hope that the catch them.Why killed them.
Are they over populated?