nothing in Simbad for it, looks to be on its own.
1 Like
as faint as they get…
1 Like
I think this is a good opportunity to talk about the unseen in the Universe. I have often thought about @tombickle who studies brown dwarfs if memory serves me right. As an Artist color theory is of great interest to me which became hightened after I discovered my Dad is red green colorblind, he had no idea until he was in his 50’s. most People see 3 primary colors and 1 million hues; trichromatic. red green colorblind folk see about 10,000 and quite a bit of that being brown. red barns look black etc. however there are an unknown few people who see 4 primary colors and at least 100 million hues. Almost all of those tetrachromatic vision people are women whos Dad is colorblind. genetics swings the other direction. Tetrachromes wouldnt really know they were different and could not describe the colors we cannot anymore than I can describe the difference between red and green to someone who cant see it. Tetrachromes see extra bands of the rainbow, tertiary colors in addition to primary 4. there are a hypothetical 6 primary colors in the visible spectrum and potentially even people who may see more than 4 of them. you can visualize this when looking at a double rainbow in between the two is Alexanders Dark Band, the webs will tell you that is simply the shadow of light, but tetrachromes prove it is the visual spectrum most are blind to. Tetrachromes see a more brilliant complete white and if a red barn be black to a colorblind person I know when a black car or black goes by I am just colorblind to what it really looks like. and here is the dilema; our ground telescopes etc scan the heavens for visible spectrum light and in RGB our LED screens also RGB are missing out on an incredible amount of visible light that is showing as black or gray possibly even browns. Where are the 4th primary color stars? we have yellow, blue, red… though faint I see a lot of dark areas that could be artifacts or background radiation in this dwarf/cloud. but what if its just a majority 4th primary color star dwarf and the light is in Alexanders Dark Band?
1 Like
I have actually written University of Iowa Astronomy Professors, Neil Degrasse Tyson and Startalk more than once and others even NASA more than once and I never hear anything back.
1 Like
furthermore if primary color four which I will refer to as Tet or Tetra (maybe we should let a Tetrachrome name it lol) is a longer wavelength which looks like it may be on the rainbow, tet could allow us to see farther away.
1 Like
Hi Joshua,
The wikipedia pages on these topics are interesting! I learned from Tetrachromacy - Wikipedia that the vertebrate common ancestor was a tetrachromat, and then mammals lost two channels, and then primates regained a third channel!
I can tell you a bit about how scientists/astronomers think about color –
the plot below is from Photoreceptor cell - Wikipedia
and shows the sensitivity or activation of the three “normal” human photoreceptors.
So one thing you can see is that the one called “Blue” is actually most sensitive to blue-violet, and then one called “Red” is actually most sensitive to yellow-green!
From the wikipedia page, it sounds like tetrachromaticity is actually pretty complicated, and the fourth channel is in between the “Red” and “Green”!
From the brain’s perspective, there are just these three channels, and based on how strongly those three channels respond, you get a sensation of color.
Of course, the world is way more complex than that! That chart just shows how strongly those three receptors respond to what scientists would call monochromatic light, like from a laser or LED. In the natural world, things almost always have complex spectra. A rainbow is one of the rare times when you actually get light split out into the pure colors!
The project I mostly work on, DESI, uses a spectrograph to collect very detailed information about individual stars and galaxies – for example, here’s a typical star,
so DESI can see, effectively, thousands of “dimensions” of color!
The images shown in the Legacy Surveys sky viewer were mostly observed in only three bands, called “g”, “r” and “z” – three of the six broad channels available with this camera.
You can see that “g” is somewhat similar to the “Blue” cone – 400 to 550 nanometers or 4000 to 5500 Angstroms (yeah, we have two units that differ by a factor of 10 … it’s silly. Astronomy is an old science with a lot of baggage!).
Then the “r” filter is somewhat similar to our “Red” cone. And “z” is off in the near-infrared - invisible to humans.
For the sky viewer, we mapped those three filters: g, r and z, into Blue, Green, Red for computer displays. I can tell you from experience that if you mess up the ordering, things look super weird! Aside from the channel ordering, there are lots of other choices about how to turn data into images – the “dynamic range” of the sky is really large – eg, the cores of galaxies are way brighter than the outskirts, so if you don’t apply a “stretch”, you mostly just see the galaxy cores and a faint impression of the outskirts, rather than the beautiful spiral arms and lovely details that we all enjoy.
For DR10, we added “i” band into the mix – we don’t need it for DESI, but other people use it for other tasks, so there’s a bunch of “archival” observations that we can use – so I had to figure out a way to map those 4 filters into only RGB! To be honest, I’m not totally happy with how it came out.
Why do we use those three bands/filters? Well, they’re pretty good at allowing us to pick out the different kinds of stars and galaxies that we want to observe with DESI. Basically, we use the three-color images to pre-select stars and galaxies that we think are going to be useful for the DESI science (mapping galaxies in 3-d) - then the detailed DESI spectra let you say for sure. For some kinds of objects, it is helpful to add in more farther-infrared information, which we get from the WISE satellite (3.4 and 4.6 microns… yes, yet another unit … 3400-4600 nanometers or 34000-46000 Angstroms!).
For the upcoming DESI-2 experiment, we’re going to use a different set of filters – 5 filters within the “g” band – basically ranging from violet to green – so figuring out how to represent those in RGB is a real challenge!
By the way – my kid is obsessed with the Mantis shrimp, which has many more kinds of color receptors! It’s fascinating (brain-busting!) to try to imaging what their color world is like!
cheers,
dustin
2 Likes
I’m gonna re-read this a few more times along with the Quasar search tool you showed me on the other post. Color theory is such an interesting topic to me. Pink for example is not part of the visible spectrum; it is a trick I realized my Dad was colorblind when he couldnt see the pink sky at sunset, things like deer blood in the forest etc was nigh indistiguishable from moss to him as s kid, but I brushed off that encounter I had as a kid tracking a deer until I was older and it was obvious, but can a person unable to see an optical illusion be said to be blind to it? Yellow light is similarly in between red and green. this Vsauce video talks about how easy it is to lie to the brain. if pink isnt really a color and we see it and we can be tricked into seeing yellow, can we see other colors not on our visible spectrum and are there “illusionary” color stars?https://youtu.be/R3unPcJDbCc?si=U5nbwn1y8k2_LnvL
1 Like
it would be incredible to have Enchroma type glasses that allow us to see like a mantis shrimp. for thousands of years mankind had no technology to correct their vision. red/green colorblind folk have rods and cones too close to one another and Enchroma glasses put a spacer in between them. sometimes red/green CB folk state they can see color better if other colors arent present like red next to green. I can only imagine the arguments that broke out over the years of humanity, calling people colorblind who denied it. We could still evolve to see color better. I think it is interesting also that the military prefers colorblind snipers cause they can see through camoflage and my Dad could pick out deer from across fields while the dazzle of colors made it difficult for me. again CB folk showing resilience from optical illusions. probably why Colorblindness stuck around.
2 Likes
I was clean shaven when I started reading this post 
2 Likes
Were you also colorblind by the end of it?