Rachel Fernandes
SIG 2: Exoplanet Demographics

Hello everyone.
My name is Rachel Fernandes and I Co chair SIG 2 with Samson Johnson. Who isn't here today, but I think is following online remotely.
So just a quick intro SIG two is the science Interest group number two and we focus on exoplanet demographics.
Just as an overview, why SIG two exists? Ish is we're essentially building on SAG 13.
Sag 13, had two different goals back in the day.
They had to evaluate what we currently know about planet occurrence rates, especially EtaEarth, and wanted to compare it and consolidate different studies to figure out what the discrepancies are and secondary they had to establish a standard set of occurrence rates accepted by much of the community and.
Possibly use permission deals and they sort of did both and if you want to really look into what they did, there's AQR code for their report.
And SIG 2 just builds on. That is to extend SQ13 to a wider parameter space.
By bringing together groups in the community to discuss this cross technique and cross population results and identify work needed to move forward.
So one of the things SIG two has done that is I think almost now two years ago.
We realized that a lot of people run a lot of different kind of detection surveys, and while they do a very good job of running the surveys in order to do demographics, we need certain meta products that only the surveys can provide us with. And that's why we.
Wrote this entire report as a guideline to the community.
For every single detection technique, what products do we need in order to properly get demographics out of it?
There's two tiers of products, tier one being the very basic requirements and Tier 2 being more advanced requirement.
We can do demographics with both.
So if you're running any surveys that are that you would like people to go ahead and run demographics and do demographic studies on, there's a whole report you can read.
You can actually skip most of it and just go to the technique you work on.
Some leadership and logistical updates. I was not always leading SIG 2.
I only took over with Sampson in June 2023 and the previous Co chairs were Jessie Christensen and Mike Myers.
We still have Jennifer Gregory and we're very thankful for her.
She keeps us in line and make sure we really meet, which is somehow a bar we set for ourselves.
We also have a steering committee.
We are two postdocs who are running SIG two and steering committee.
Helps us. Just make sure we're making the right decisions and kind of leads us in our leadership, the steering Committee reformed is Natalie Batalia, Bertrand Madison, Sam Quinn and Lisa Quintana, and we meet roughly every six months to provide updates on what SIG two has been up to.
And ask for the advice moving forward.
We meet every second Friday of the month and it's been pretty regular, barring breaks since Sampson and I took over, we were really focused on increasing the number of.
Ali Korea researchers. In fact, I think before Sampson and I took over, there were four, including Sampson and I. And now there's at least 30 early career folks.
By that I mean a lot of graduate students, some undergrads, and a lot of postdocs, and they've been very active in working towards what I'll go in the next few slides.
We also established a short, very short, very brief code of conduct that I've made even briefer over here.
We remind people every month that.
To be respectful, to engage in active listening.
You are allowed to give constructive criticism, but there's a way to do that.
No harassing.
This is just to make sure we have a healthy dynamic as SIG 2 and so far we've had no issues.
Currently, what we are focusing on is a review of EtaEarth, all of us or most of us, see this plot quite regularly, and it's you can take two things away from this plot. One, we really agree on EtaEarth one. We really disagree on EtaEarth.
And that's the problem is that when you show people this plot, it doesn't tell you why we agree or why we don't agree on a data Earth.
So what I seek to we're doing is we are writing a review of why EtaEarth is a complex problem to solve.
We're actually almost done.
We are planning on a submission soon and in the next few slides I'll go into a few more details about it.
This is a reminder we're not trying to reproduce what SAG 13 did.
We're just shedding light on the problems, almost like.
A dictionary.
The problems?
EtaEarth has.
So this is what we've been working on.
This is a figure we made.
It is meant to induce a little bit of panic and it is not a complete figure as of yet.
What you're seeing over here is all the different things that EtaEarth depends on. In pink, you are seeing the planetary parameters.
In purple, you're seeing the cellar parameters, and in blue you're seeing the methodology.
This is a figure we've only made in the past month when people were on break. So we're still actively working on it.
But each of these ingredients.
That go into Ada, Earth shift, EtaEarth and it's ADA and it's arrow bars. And so we to in our report talk about it to 1st order.
What are the different changes that happen? But we're not solving, we're not taking into account all of this.
This is just what we're discussing in the report.
Our report is divided into two sections, 2 main sections. The first one is just consolidating definitions and summarizing past efforts on measuring EtaEarth analogues, and so this includes all chronological changes we're not.
We only have a tiny section, but we're not fully focusing on Kepler.
We're focusing on the problem itself rather than what 1 mission or one technique can provide us the latter sections.
We're identifying pathways forward, so how exactly, for example, does planet multiplicity play a role again to 1st order?
We're not solving for it.
And also how the future missions like Rome, inhabitable worlds, observatories, how they can get us closer to Mabry measuring EtaEarth or?
Even finding more Earths.
To submit this in May 2025 to the was journals, this is a call we made as a team. Given the large number of early career researchers on the paper, we didn't want this to be a white paper, but an actual paper.
That's peer reviewed for the community and the community can use as as a document so that will be if people want to join this paper, feel free to e-mail me if you want to provide comments inputs, we'd be happy to add you to the paper as well.
Looking forward, once we are done with this EtaEarth paper, which we are aiming for summer, we want to move forward and use SIG to essentially as a hivemind for demographics to see what can we do for future missions, exactly how we can.
Complement NASA's missions, for example, Roman Space Telescope is going to give us a lot.
A lot of exoplanets.
How exactly can we do demographics with it?
How can we do comparative demographics with it?
That's one of the ideas we have. And secondly.
We also have an idea of maybe creating a White paper, synthesizing exoplanet demographics across various techniques. The positives and negatives may be providing community tools.
It's something that's still under wraps because we've been focusing on EtaEarth, but those are just the two main ideas we have that we will focus in on the next two years.
So if you're interested in joining SIG 2, e-mail me Samson or Jennifer and we'd be happy to have you on, especially for the EtaEarth paper. And in general as well.
I have a very short talk today.
That's it from my side.
Right. Well, we've got about four minutes for questions. If anyone has any questions for Rachel.
What path forward?
Is the.
Let me formulate a question first.
We got 4 minutes like you said.
If it comes from differing ideas about what constitutes earth like, could you comment on like something that maybe characterizes the wider dispersion of those ideas as opposed to the commonality?
Can you repeat that?
Yeah, with differing ideas about what constitutes earth, like there could be narrow ideas or quite differing ones.
I'm wondering about how different they might be.
Very is the idea and I'm going to focus on Earth sized over earth like because.
EtaEarth cares about finding Earth sized planets in the habitable zone of sun like star Earth like is more of a habitability question which is way beyond my wheelhouse.
I would say there's a very wide definition. Some people think that you can go down to .3 Earth radii.
Some people say sub Neptune stripped cores are fine.
Moon's of Jupiter are fine.
It's it's really, really wide. And so we try to take all those boxes when we are discussing it to say that it's something that till we find the next earth, we will not know what the answer is.
As we build that sample, so for now, we're just saying that these are all the options it's going to be more of a process of elimination as we move forward. But I don't think there's a real consensus in the field about it.
Alright. Any other questions?
Great. We can thank Rachel again. One more question.
Sorry. No, no, perfect.
Yeah. I was gonna ask about the hideous diagram you put up with all of those.
It's my favorite.
Yeah, I couldn't read any of the text because it was just so, so much.
But I'm curious if there were anything you found in looking through the literature that was maybe surprising and the different ways that people measure or estimate EtaEarth.
Like, are there any of those little boxes that we might not expect?
I think so.
I think in the paper they took away the slides from here, but let me see.
Should work. So in the paper we'll go into it in more detail and as this figure evolves, but there is some method to the madness in here in the sense that from literature.
From what we understand, the more bold lines and the bold outline boxes are the ones where we understand those things better.
And literature is actually attempted to cover those in a more holistic way, whereas anything with dotted lines is still kind of up in the air and a lot of it is methodology.
And we there's a lot of literature out there.
We have tried to concise it like.
Make it as concise as possible.
Nothing over here personally surprised me. I think I was more surprised at how are we going to do this more than anything else and what data set are we going to use?
And that was kind of the point of the paper that we're trying to do is to kind of let people think that this is more complex of a problem than some of us have thought before.
And there's no right or wrong way of doing it.
We're all doing it wrong, so sorry.
Alright. Well, thank you, Rachel.