
How to Discover a Galaxy with a Telephoto Lens - bootload
http://nautil.us/issue/32/space/how-to-discover-a-galaxy-with-a-telephoto-lens
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antognini
Ultimately the reason these small telescopes are so useful for finding these
faint, diffuse galaxies is because the surface brightness of an object is
independent of the collecting area. Larger optical telescopes have much better
resolution, so the amount of light detected from a diffuse galaxy is fairly
similar per pixel to a little telescope like Dragonfly. But a little telescope
costs probably about three orders of magnitude less than a big telescope and
you can afford to hammer a particular target night after night, whereas you'd
be lucky to have an hour of time on a large telescope.

There are a number of other great small-telescope projects in different areas
of astronomy. The one closest to my heart is ASAS-SN (pronounced "Assassin")
since it was the idea of the professor across the hall from me when I was at
Ohio State and an officemate of mine was the one who spent much of his
graduate career building it. The idea was to get a little telescope (like
Dragonfly it's pretty much just a telephoto lens with a detector attached) and
then have it look at ~1/3 of the sky every night. That way if a supernova goes
off in a nearby galaxy (or there is some other transient) it's discovered
within a few days. Just this month they published a paper on the discovery of
the brightest supernova ever observed [1]. They currently discover more
supernovae than all other groups combined (including amateur astronomers, who
are a formidable force!).

There's another small-telescope project built to search for exoplanets called
KELT (the Kilodegree Extremely Little Telescope). Since transiting planets are
generally detected around bright stars (at least in apparent magnitude),
telescope size is not so important for their discovery. In fact, having too
big a telescope can be an issue because the host star is so bright that it
saturates the detector. So far they've discovered (I think) somewhere around a
dozen planets, though my favorite is Kelt-4Ab because it's in a triple star
system (and also because I'm on the paper) [2].

[1]:
[https://en.wikipedia.org/wiki/ASASSN-15lh](https://en.wikipedia.org/wiki/ASASSN-15lh)

[2]: [http://arxiv.org/abs/1510.00015](http://arxiv.org/abs/1510.00015)

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seiferteric
I had an idea a while ago for a "telescope as a service" platform. The idea
was to build relatively small telescopes and put them in ideal places (maybe
partner with existing observatories). They would be fully controllable via api
and from a web interface. I was thinking it would be a good educational
resource for educators, you could connect and use a telescope right in your
classroom during the day, on the other side of the world where it is dark.
Researches could buy time and program them to observe the sky as well since as
you said, even small telescopes can be useful for some types of astronomy.

~~~
Outdoorsman
IMO teachers would be very receptive to an opportunity to do just that...if
you're thinking of dev for a subscription service my advice would be to keep
it affordable--education budgets are much smaller than they should be...

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seiferteric
My inclination would be to make it a non-profit.

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Outdoorsman
Have some experience with non-profits...

Some options for seed money:

Partnering--combine your request(s) for funding with other providers, or
beneficiaries (schools).."collaborating" is big just now...

Grants--arduous route with a steep learning curve in terms of writing
effective proposals...

Benefactor-- local moneyed enthusiast who wouldn't mind making the news with a
bit of altruism...

Solo--funding it yourself then selling it...

Good luck!

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acqq
The paper by Dragonfly designers:

[http://arxiv.org/abs/1401.5473](http://arxiv.org/abs/1401.5473)

It's not "just" the off-the shelf lenses and cameras, although the lenses are
really the crucial part and they are very cleverly used, achieving up to then
never achieved low light scattering. At the time it used only 8 lenses, the
telescope had weight of more than 100 kg.

Here's the robotic mount they used then:

[http://www.bisque.com/sc/pages/ParamountMEII.aspx](http://www.bisque.com/sc/pages/ParamountMEII.aspx)

The paper with the first results from the Dragonfly:

[http://iopscience.iop.org/article/10.1088/2041-8205/782/2/L2...](http://iopscience.iop.org/article/10.1088/2041-8205/782/2/L24/meta)

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dharma1
The paper mentions "science grade CCD sensors" \- are these really better than
some of the new ultra low light CMOS cameras from Sony and Canon?

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aggie
The sensors used are Kodak KAF8300, which are a stand-alone sensor that you
hook up to a laptop. They are designed specifically for astronomy, and perform
better in some ways than typical consumer cameras. DSLRs that are marketed as
tuned for astrophotography often have better sensitivity to certain key
wavelengths than their standard counterparts (especially hydrogen-alpha at
656nm), but are missing other benefits of 'science-grade sensors'.

"Astronomical CCD cameras are a whole different world from DSLR cameras. These
are cameras designed exclusively for AP, and most offer active cooling. The
nature of a CCD vs a CMOS sensor in a DSLR results in a camera that is higher
sensitivity, but also higher noise. Many Astro CCD cameras have mono sensors
(no bayer color layer) which means they are used with filter wheels with
different colored filters to capture a natural color image. They can also be
used with various narrow-band filters to capture light outside the visible
spectrum."

from [http://soggyastronomer.com/the-best-dslr-cameras-for-
astroph...](http://soggyastronomer.com/the-best-dslr-cameras-for-
astrophotography/)

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dharma1
Nice. Did a bit of reading on this, looks like high as possible quantum
efficiency (across a broad spectrum) is what is desired.

You are right, most DSLR cameras lose about half of the QE to the rgb filters.

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stcredzero
_They were also frustrated with how cumbersome astronomy had become: Modern
astronomical projects are typically large-scale affairs, requiring a small
fortune, a mountain of paperwork, and plenty of patience. “You have to
envision ways to get $10 million and put a team together, and even then, you
only know if things will come to fruition a decade later,” says Abraham, a
professor at the University of Toronto._

Sounds like big company software development.

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vvanders
Taking two expensive hobbies(photo + astro) and combining them!

Also my jaw dropped a bit when I saw all those white telephotos packed
together, that's a lot of glass!

~~~
ajross
Only one hobby. These folks are professional astronomers.

