Hack Chat Transcript, Part 1

A event log for Habitable Exoplanets Hack Chat

Twinkle, twinkle little star

dan-maloneyDan Maloney 01/15/2020 at 21:030 Comments

OK everyone, let's get started. Welcome to the first Hack Chat of 2020! We had a long holiday hiatus there, but we're ready to go again, and I'm happy to have Alberto Caballero from the Habitable Exoplanets Hunting Project here today. He's going to tell us all about a citizen science effort to find nearby planets that might support life.

Joshua Johnson12:01 PM

Alberto, can you tell us a little about your background and how you got interested in this?

TheExoplanetsChannel12:02 PM
Sure. Basically I have been an amateur astronomer for around 5 years.

TheExoplanetsChannel12:03 PM
But I became interested in the detection of exoplanets just a couple of years ago.

TheExoplanetsChannel12:05 PM
Initially, I bought a tele-photo lens and an astronomical camera to learn transit photometry, that is, the detection of exoplanets by searching for changes in the brightness of stars

TheExoplanetsChannel12:05 PM
But at some point I realized that my equipment wasn't enough to search for potentially habitable exoplanets

It seems like something you'd need millions of dollars of equipment for. How can amateur instruments actually be useful for something like that?

TheExoplanetsChannel12:07 PM
Exactly. Many people, even amateur astronomers, still believe that it's not possible to detect exoplanets with amateur equipment.

TheExoplanetsChannel12:08 PM
I would say it depends on what type of exoplanet we want to detect. Anybody with a small tele-photo lens, a DSLR camera and an astronomical mount can detect gas giants, which are the biggest exoplanets.

TheExoplanetsChannel12:10 PM
The idea is to attach the camera to the lens, gather data (the light coming from the star) and search for changes in the brightness of the star

TheExoplanetsChannel12:10 PM
When exoplanet 'passes' between us and the star, the software will register that change in brighteness.

TheExoplanetsChannel12:10 PM
Of course a computer is also needed to process the data.

That just blows my mind that off-the-shelf gear is sensitive enough to watch a star a hundred light years away go slightly dimmer when a planet passes in front of it.

anfractuosity12:11 PM
very intriguing! my astronomy isn't great, but would that also detect things like pulsars etc.?

anfractuosity12:13 PM
also are you processing video in realtime?

TheExoplanetsChannel12:13 PM
Well, I would say pulsar are more difficult to detect with amateur equipment.

anfractuosity12:13 PM

anfractuosity12:13 PM
i'm curious what software you're using

TheExoplanetsChannel12:14 PM
I wouldn't say it's impossible thoughl

TheExoplanetsChannel12:15 PM
I don't usually process images in realtime.

TheExoplanetsChannel12:15 PM
I usually spend the night taking images, and then I process all the data the next day.

TheExoplanetsChannel12:15 PM
Yes, I like to use AstroImageJ for processing.

TheExoplanetsChannel12:16 PM
It's a free program and very easy to use

anfractuosity12:16 PM
cool, i've not heard of that program, will have a look. So do you use something like an intervalometer (sp?) that takes a single photo at a certain interval?

TheExoplanetsChannel12:17 PM
Btw with respect to the last question , I would say that pulsars could be detected with amateur radio telescopes.

TheExoplanetsChannel12:18 PM
Well, I set the imagining intervals in the software settings.

anfractuosity12:18 PM
ah gotcha, do you use a special firmware then i guess (i've got a canon dslr, but it can't do that by default)

TheExoplanetsChannel12:19 PM
To image, I use a software different than the program I use to process the data.

TheExoplanetsChannel12:19 PM
As far as I'm concerned, no special firmware.

anfractuosity12:20 PM
ah but you mentioned software, is the camera attached to a laptop then?

TheExoplanetsChannel12:20 PM
Yes, I also plug the camera into the laptop

TheExoplanetsChannel12:21 PM
I have an astronomical camera called ZWO ASI 120 MM

anfractuosity12:21 PM
ahh gotcha

TheExoplanetsChannel12:21 PM
If I had a DSLR, no laptop would be needed

TheExoplanetsChannel12:21 PM
but yes, despite more difficult, it's also possible to detect exoplanets with dslr cameras

TheExoplanetsChannel12:22 PM
rocky exoplanets are a whole different world

TheExoplanetsChannel12:22 PM
that's why I decided to create the habitable exoplanet hunting project


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Remarkably affordable. I suppose the telescope is the expensive bit though

anfractuosity12:23 PM
cheers, i was just having a browse of that site, i imagine they're a lot better than a dslr for this, and also presumably don't have a shutter that breaks

anfractuosity12:23 PM
like a dslr

TheExoplanetsChannel12:25 PM
Yes, well the camera I had, the ZWO asi 120 MM wouldn't be enough to detect rocky exoplanets, or at least it would be difficult

TheExoplanetsChannel12:25 PM
to detect or discover rocky exoplanets, I would recommend cameras with a bitrate of at least 14 bits

anfractuosity12:26 PM
sorry, whats a rocky exoplanet, how does that differ?

TheExoplanetsChannel12:26 PM
Yes, they are better than dslrs, especially the mono-chrome cameras

TheExoplanetsChannel12:27 PM
a rocky exoplanet would be a planet with a very thin or almost inexistant atmosphere, they are much smaller than gas giants, and, therefore, more difficult to detect

anfractuosity12:28 PM

TheExoplanetsChannel12:28 PM
the type of star is also important. The bigger the star, the more difficult will be to detect a transit, and the smaller the star, the easier

TheExoplanetsChannel12:29 PM
For those who never detected an exoplanet, I recommend starting with HD 189733 b

TheExoplanetsChannel12:29 PM
it's the easiest one to detect in the northern hemisphere

anfractuosity12:29 PM
do you have any videos per chance, of the brighness of a star changing in a way that indicates an exoplanet?

TheExoplanetsChannel12:29 PM
and it's a very strange exoplanet because there it rains glass sideways

morgan joined  the room.12:30 PM

So have you found any previously unknown exoplanets yet?

TheExoplanetsChannel12:30 PM
Yes, here is a video I made explaining step by step how to detect and potentially discover exoplanets:

I heard a 17-year-old found one on his first day of a NASA internship recently

But I think he was crunching data, not doing the actual observations. IIRC the data was from TESS

morgan12:32 PM
whoa, that camera seems very affordable, is it stand-alone or an attachment to another device?

TheExoplanetsChannel12:32 PM
I'm afraid we haven't found any exoplanet yet. We have observed 2 stars so far: GJ 436 and GJ 1214. Right now we are observing GJ 3470. This campaign will finish the 15th of march.

morgan12:32 PM
oh I think I see, it's an attachment to a telescope. I have some of those

TheExoplanetsChannel12:33 PM
That last discovery was indeed great.

Can you talk a little about the network you've put together?

TheExoplanetsChannel12:33 PM
Exactly, what we are doing is to gather our own data.

TheExoplanetsChannel12:34 PM
The problem with those type of cameras is that they are , in general, not stand-alone. They need a laptop.

morgan12:35 PM
also have one of those

TheExoplanetsChannel12:36 PM
Yes. Basically we are 33 observatories from around the world, the 5 continents. All of them are observing the same star, but they observe it at different times. This way, we try cover the star 24/7.

Joshua Johnson12:37 PM
Have you observed any other stellar objects besides exoplanets?

TheExoplanetsChannel12:37 PM
Most of them are amateur observatories, and most of these observatories have previous experience in confirme exoplanet candidates from Kepler and TESS.

TheExoplanetsChannel12:38 PM
There are also 3 universities involved in the project.

anfractuosity12:38 PM
I'm just wondering, since stars twinkle when viewed from earth, i assume that's not an issue which affects your data?

TheExoplanetsChannel12:38 PM
Not really, we only focus on stars. Actually, we only observe each star for a specific amount of time.

TheExoplanetsChannel12:39 PM
We only search for exoplanets actually.

morgan12:40 PM
@TheExoplanetsChannel is there a website for this project network? I work at and would throw this out to our observatory staff & volunteers

TheExoplanetsChannel12:40 PM
Thankfully, the twinkling is not an issue. The observatories involved have very good cameras. But indeed, observing during the winter is better than during summer.

anfractuosity12:41 PM

TheExoplanetsChannel12:41 PM
Oh that's great, thanks a lot. Yes this is the website:

morgan12:42 PM
cool! I'll pass this around

TheExoplanetsChannel12:42 PM
Thank you :9

TheExoplanetsChannel12:42 PM

I've got a telescope similar to this:


NexStar 4SE Computerized Telescope

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TheExoplanetsChannel12:43 PM
That would work great indeed

Would that be appropriate for observing exoplanets? With an appropriate camera, of course.

TheExoplanetsChannel12:44 PM
As far as I'm concerned, that has the same diameter as the TESS telescope.

David Troetschel12:44 PM


Canon U.S.A., Inc. | The EOS Ra - A New Astrophotography Camera

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Read this on Canon

Really? Wow, I might just have to take that out of storage.

morgan12:44 PM
and the network grows

TheExoplanetsChannel12:44 PM
Yes, I would say it would be perfect for exoplanets.

anfractuosity12:44 PM
what telescope are you using btw @TheExoplanetsChannel , sorry if you already said?

Frank Buss12:45 PM
don't you need a parallactic mounting for long exposure?

anfractuosity12:46 PM
i don't think they're doing long exposure are they?

anfractuosity12:46 PM
i could be mistaken thoo

TheExoplanetsChannel12:46 PM
I didn't know the EOS Ra, it certainly looks great, but I would say that, for exoplanets a mono-chrome camera would be better.

TheExoplanetsChannel12:47 PM
Right now I have a skywatcher explorer 150, but I don't use it for the project.

Just curious - did the recent LIGO gravitational wave detection interrupt any of your observations? I heard that the announcement caused a lot of observatories to preempt their regular observations to watch the sky in that area.


An 'unknown' burst of gravitational waves just lit up Earth's detectors

Earth's gravitational wave observatories -- which hunt for ripples in the fabric of space-time -- just picked up something weird. The Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo detectors recorded an unknown or unanticipated "burst" of gravitational waves on Jan. 14.

Read this on CNET

TheExoplanetsChannel12:48 PM
Well, it's possible to detect exoplanets with both an equatorial mount and an altazimuth mount. I would recommend equatorial though.

TheExoplanetsChannel12:50 PM
Well , the problem with altazimuth mounts is that, if you take images of an exposure longer than approx 30 sec, star trails will start to appear

anfractuosity12:50 PM
roughly what exposure time are you using btw?

anfractuosity12:50 PM
and how many photos per observation period

TheExoplanetsChannel12:51 PM
and to detect any exoplanet with the transit method, one has to gather light from the target star as well as nearby stars

TheExoplanetsChannel12:52 PM
as far as I'm concerned, none of the observatories interrupted observatories due to LIGO

TheExoplanetsChannel12:53 PM
a few of them are sometimes unable to observe because they have to confirme NASA candidates

Gotta admit, though - I'd really like to see Betelgeuse go supernova. Imagine being able to see it even in the daytime!

And yes, I know the LIGO observation probably has nothing to do with Betelgeuse's recent dimming, but still...

TheExoplanetsChannel12:54 PM
the exposure time can go between a few seconds to a couple of minutes, normally 30 secs would be enough

anfractuosity12:55 PM
gotcha, cheers

TheExoplanetsChannel12:55 PM
and the number of photographs I would say it can be 300, 500 approx

TheExoplanetsChannel12:55 PM
I agree, watching a supernova would be amazing