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Dr. Alysa Orbits (Obertas)

@astroalysa.bsky.social
905 followers 302 following 352 posts

Queer & disabled astronomer formerly at UofT & CITA. Dynamics, planets, & ballet. Posts reflect opinions of Sailor Galaxia, not my employer. She/her 👩‍🔬💃

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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 8h
What does it say about me that I'm still amused by the footnotes in my dissertation intro? I'm probably the only person who thinks they're funny, but at least I can keep myself entertained :)
16: Or at least, one has not been determined in the last ∼ 400 years or so.
17: While not a bastard, Hamilton became an orphan as a teenager in 1819 when his father passed away (his mother passed away in 1817). Similarly, he grew up to be a scholar, got his education, did not forget from whence he came, and the world knows his name.
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 13/10/2026
Screaming, crying, throwing up
Hand-written notes of orbital dynamics stuff. Shows equation for specific energy, denoted by the lowercase Greek letter xi (it looks like a squiggle, but it's supposed to be written in a particular way and I didn't do a great job of it)
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 05/07/2026
Sometimes, when I need a little pick-me-up, I remind myself that this is the top Star Wars fic on AO3
Stats:
Published:2015-12-19, Words:12, Chapters:1/1, Comments:8,628, Kudos:68,364, Bookmarks:2,376, Hits:474,233

a reylo fic
treezie

Summary:
short rey/kylo fic :)

Notes:
(See the end of the work for notes.)

Work Text:
rey picks up kylo and dunks him into the garbage. fucking obliterated

Notes:
rey is a lesbian and this ship fucking sux
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 04/06/2026
Cat orbits for anyone curious. You can ignore the caption's technobabble and just meow.
Plot of the standard map showing the angle (theta) on the horizontal axis from 0 to 2pi and action (I) on the vertical axis from 0 to 2pi. There are a bunch of dots scattered sporadically. There are two regions showing  concentric ovals. The final outer loop looks like an oval with pointy cat ears.

Caption: Figure 1.10: Behaviour of the standard map with the stochasticity parameter K = 5. This shows a saved snapshot of an interactive “click plot" in a Jupyter notebook where clicking within each panel sets a trajectory’s initial condition. Each trajectory is iterated 1000 times. The horizontal and vertical axes are periodic (i.e. mod 2π). The shape of the period 2 trajectory resembles a cat close to the separatrix, which I call “cat orbits". A version of the code for this click plot is available on github at https://github.com/aobertas/standard-map.
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 04/06/2026
Why was I allowed to submit this?
When K = 5, the shape of the period 2 trajectory resembles a cat close to the separatrix (shown in Fig. 1.10). I describe these as “cat orbits". I am not sure if these trajectories have been noted in the literature, nor do I know if any other trajectories have been previously referred to as cat orbits. I don’t have much to say about these cat orbits except that they are very cute^{footnote 28}.

footnote 28: I regret the timing of this discovery (the day before this dissertation’s submission deadline), as I would much
rather have written a dissertation on cat orbits.
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 04/06/2026
Nope. Not even remotely.
In the sense that a computer goes beep boop and does the thing.
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 04/06/2026
I don't think I was okay when I was writing this.
EVERYWHERE!!!
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 04/06/2026
I forgot just how unhinged the footnotes are in my dissertation intro.
Hopefully mine won't lead to my mum being arrested on suspicion of witchcraft.
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 08/12/2025
A story in my save files (read from bottom up)
Screenshot from Crusader Kings 3. Loading saved games

Executed grandson 
Confront grandson 
Why is my grandson murdering people 
Feast
War won
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 27/11/2025
Dark mode of my transit method gif is now on wikimedia commons! :) commons.wikimedia.org/wiki/File:Ex...
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 26/11/2025
Omgomg my gif demonstrating using the doppler/radial velocity method for detecting exoplanets was used in the latest PBS Space Time!!!!! 🤩
Screenshot of PBS Space Time video titled "Do We Live in the Rarest Solar System In The Universe? We're about to find out!"

Image shows four panels. Upper left is a top-down perspective of a planet orbiting a star, showing both orbiting the centre of gravity of the pair (showing the "wobble" of the star). Bottom left is an edge-on perspective of the same pair. Upper right is a graph showing the edge-on speed of the star (which follows a sinusoidal curve). Bottom right is a depiction of the star's spectrum, showing dark absorption lines which move due to the doppler effect (which is how the edge-on speed of the star is determined).
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 21/11/2025
Astronomy & science history folks, does anyone know more about what this would have been used for? Just saw it in the Saints, Sinners, Lovers, and Fools exhibit @romtoronto.bsky.social! 🔭 I'm guessing we're seeing a depiction of the "heavens" (celestial sphere). I also spot the names of the planets
Old book showing what looks to be the "heavens" (probably the celestial sphere) and there's a table underneath with the names of the planetsBook of Hours with Astrological Numbers until 1995, 1500
Ink, parchment, leather
Unidentified maker or makers, active in Saint-Omer
The Phoebus Foundation, Antwerp, Belgium

Livre d'heures contenant des nombres astrologiques jusqu'à 1995
1500
Encore, parchemin, cutie
Artiste(s) anonyme(s), actif(s) à Saint-Omer
La Fondation Phoebus, Anvers (Belgique)
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 12/09/2025
Just a little creepy
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 24/08/2025
I'm watching a documentary series about Jane Austen and the subtitles are comically large. It's like they assumed anyone watching this is 80+ years old
Still from documentary showing a man talking. Subtitles are large (two rows representing approx. 20% of screen height) and read, "A very close study of what somebody sees,"
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 05/03/2025
Tumblr screenshot
intactics-deactivated20211231

and i don’t necessarily believe any of this i’m just saying words recreationally 

166,386 notes
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 04/03/2025
Heartbreaking: The Worst Person You Know Just Made A Great Point
March 4, 2025
photograph of Doug Ford speaking at a press conference
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 21/02/2025
I looked up the errata to see if this is a known error. It says there's an error in the figure, except that the error is L and that the correct version is 90 - L. So it would seem that my copy of BOB has been "corrected". Is there a different convention for latitude that I'm unaware of?
4. page 11, Figure 1.12(a): Within the diagram, L should be replaced by 90 - L.
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 21/02/2025
Quick question about the celestial sphere and figure 1.12 from Carroll & Ostlie 🔭 Am I losing my mind or should the angle between the horizon and NCP be L rather than 90-L? If you're at the equator (L=0), NCP is on the horizon. If you're at the north pole (L=90), the NCP is at zenith. No?
diagram demonstrating the locations of the sun at multiple dates throughout the year for a local observer's perspective (at latitude L), with important features of the celestial sphere (poles, equator) noted
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 10/02/2025
Every time I wear this shirt I secretly hope that someone will ask me to name 5 Joy Division Songs just so I can ask them to name 5 pulsars (at which point we will then have a nice and fun conversation about neutron stars)
Photograph of me in a black t-shirt with a graphical design based on the Joy Division album Unknown Pleasures (which itself was taken from a visualization of pulsar PSR B1919+21 pulse data), except they're cats
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 08/02/2025
Also I googled Reylo to make sure I got the name right and this is literally the first image hahahaha (art by Bob Al-Greene)
Artwork of Kylo Ren and Rey from Star Wars. They’re in an embrace and the pose is very similar to the Northanger Abbey cover
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 08/02/2025
This is perfect cover art for a modern day Northanger Abbey starring a Catherine Morland who’s obsessed with Reylo fanfic. Is it good cover art for the original text? Absolutely not 😬
Penguin Random House cover art for Northanger Abbey by Jane Austen. It has brightly-coloured artwork of a man and woman (both in modern clothing) in an embrace. The man sort of resembles Adam Driver
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 05/02/2025
?????????
Screenshot from Assassin’s Creed 2
Giotti’s Campanile
The tower is clad with white marble from Carrara, red marble from Siena and green marble from Prato. It takes exactly 414 steps to reach the top, perhaps predicting Charles Messier’s discovery of the Whirlpool Galaxy exactly 414 years later. Or perhaps not.
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 03/02/2025
It wasn’t this one, but I’m choosing to believe that every shocked or angry expression is because that person agrees with me
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 30/10/2024
It is October 30th
Weather in Toronto 

Now: 20°
High: 21°
Low: 15°
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 24/02/2024
I'm so excited for this
Dominic Monaghan & Billy Boyd
In
Rosencrantz & Guildenstern Are Dead

(Photo with Dominic Monaghan & Billy Boyd both looking kind of just confused and exhausted)
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 13/09/2023
Using viridis for all of my figure colours so my papers look like this
"Jazz design" featured on Solo disposable paper cups in the 1990s. Thick turquoise squiggle with a thin purple squiggle on top
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 08/09/2023
REBOUND's WHFast integrator in a nutshell 🔭
Rather than outline the methodology of the original Wisdom-Holman scheme^[41] (I refer readers to Wisdom and Holman, 1991), I outline the approach taken by WHFast (i.e. the one used in this dissertation’s projects).

WHFast
Wisdom-Holman 2: electric boogaloo (or how to make a computer go beep boop and do the thing harder, better, faster, stronger)

1.4.2 SPOCK: a Machine Learning Tool to Predict Stability

SPOCK predicts the probability that a multi-planet system is stable within 10^9 orbits and is (nominally) up to 10^5 times faster^[42] than integrating the system for the same duration. SPOCK uses

footnote 41: It is approximately as old as me.
footnote 42: In practice, computational overhead when running scripts means that SPOCK is typically ∼ 10^4 times faster. This depends on several factors, however.
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 01/09/2023
It's been found! 😻
Turquoise sock with cartoon cat faces (calico, black, gray)
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 27/08/2023
I need Lego to know this is actually a track loader and not a bulldozer, thanks
Lego kit named "construction bulldozer". It shows an assembled bulldozer (actually a track loader) and a trailer (with a cement mixer in the back), a fixed crane (with a wrecking ball attached), and various construction items
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 27/08/2023
My stepsister organised a really lovely celebration party for me at a nearby tea place today 😊
Photo of a three tier tray with small sandwiches (bottom), scones (middle), and desserts (top)
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 26/08/2023
How are you already at 1.7k followers on here @frogs4girls.bsky.social????
worm food (anna)
@frogs4girls.bsky.social

1.7K followers

297 following

1.2K posts

anna | she/her || 24 | cutie pie | astrophysics grad @ Leiden Uni | virgo | jew for a free palestine | life's more painless for the brainless! | pls be nice to me
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 15/08/2023
In 2021, I made a similar animation showing the transit method for detecting exoplanets. It's also up on Wikimedia commons! 6/n
top left: bird's eye view of planet orbiting a star
bottom left: edge-on view of same system, showing the planet crossing in front of the star (i.e. transiting)
top right: brightness of star vs time, ranging from 100% to 94%, with marker showing the star's current brightness; the brightness sharply dips when the planet is transiting
bottom right: what brightness of star would look like on a telescope's detector

all four panels are in sync and change with the planet's orbit
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 15/08/2023
In 2018, I made an animation showing the radial velocity method for detecting exoplanets to use in a public talk. It's up on Wikimedia commons for anyone to use! 5/n
top left: bird's eye view of a planet and star orbiting their centre of mass (i.e. the planet orbiting the star and the star "wobbling")
bottom left: edge-on view of same system
top right: speed (of star) vs time for same system, varying smoothly in a wave from -10m/s to 10m/s
bottom right: spectrum of star's light, showing absorption lines (with doppler shift) as well as lab-values
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Dr. Alysa Orbits (Obertas) @astroalysa.bsky.social · 15/08/2023
In 2015-2016, I was in a team led by Jielai Zhang and Pegah Salbi to raise $10k for Syrian refugees & newcomers via planetarium shows (w/ free shows in Arabic for newcomers) www.utoronto.ca/news/choirs-planeta… 2/n
Photo of the team.
Bottom row, left to right: Alysa Obertas, Pegah Salbi, Jielai Zhang, Lisa Esteves
Middle row, left to right: Max Millar-Blanchaer, Christa Van Laerhoven, Heidi White, Alexander Rachkov
Top row, left to right: Siqi Liu, Mike Williams, Charles Zhu
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