Celestia Forums

So in recent years i've started doing some research of my own, with much-appreciated help and support of the Celestia community. Over time though, i ended up doing some discoveries (and disprovals) of my own! Some confirmed, some unconfirmed, and some based on or made alongside others.
Sirius_Alpha once jokingly said: "This is how new discoveries should be announced -- through Celestia addons." So with that out of the way...

ASTEROIDS
2021 PB130
The first little dot
Status: Confirmed, on road to numbering

A member of the Eulaila family of asteroids, 2021 PB130 is the dimmest object i've studied so far (Peak magnitude: 21.5-22). While i found it on the IASC campaigns, its unlikely that the discovery credit will go to me due to some MPEC 2010-U20 shenneningans. Still though, i feel proud of finding it in the first place.
In terms of numbering, I'm just one opposition away from getting it a chance of numbering per the MPC criteria. I'm not sure what Lowell's criteria think about it. It should be numbered by 2025 at most, possibly even this year.


2023 HU18
Keeping Nyrath in good health
Status: Confirmed, on road to numbering

This one is one i'm 100% confident in calling it mine. An inner MBA in an interesting 12:7 resonance with Mars, it likely has a relatively high albedo and small size. 2023 HU18 was the first asteroid candidate i put the international-based designation instead of the MCTI one (TGL0001), and to see it confirmed relatively quickly is nice to see!


EXTRASOLAR
Przybylski's Star (V816 Cen C1)
Well, that's going to be a fun one to the media...
Status: Unconfirmed

This one is an interesting world to be sure if its real. Its a super-Jupiter orbiting at 4 AU from the star. The issue? That's just beyond Przy's habitable zone! I'm gonna hate the media's reaction to this if it gets confirmed.
Thankfully for me its only not confirmed because of two things:
- Przybylski's Star is a weird one. CCFs break down here so maybe SERVAL's custom CCFs based on existing spectra of the star work better for it.
- Przy is a rapidly oscilating Ap star. This gives a very scary thought: What if those are just systematics from the oscilations?


ASASSN-V J213939.3-702817.4 (b/B?)
Wiki doesn't know, but i do
Status: Unconfirmed (single transit)

Ah yes, the non-variable star which suddently dimmed by 70% and with no end in sight. Except of course it did, everyone just forgot about the star until today!
So now in 2024, we know it was caused by... a transit? And the transiting body would need to be the size of the Sun? That doesn't make sense!
Of course it doesn't, its astronomy. So i put two models: one with a disked planet/BD and one with a late M-type dwarf. Beautiful star, isn't it?


2MASS J06380069+1022493
...limit? LIMIT? I've got your limit RIGHT HERE!
Status: Confirmed (still weird tho)

So this star is an SX Phoenicis variable. It pulsates every 20 or so minutes. SX Phe stars have spectral types between A and F. So you'd expect then to have a whitish blue color typical of "warm" stars. And since they're basically cousin variables of Delta Scuti variables, you'd expect that the limit would be just white, late F at most.

This star is K3V. I'm not kidding, just ask Gaia DR3. And apparently TESS photometry agrees: it really is an ultra cold SX Phe variable. How is this possible? No idea!
Of course i don't have anything else to say about it, its an otherwise unremarkable star.


Added after 2 minutes 31 seconds:
K2-256 (b) and TYC 4941-622-1
Celestia is a planet killer
Status: Disproven (by Sirius_Alpha and i!)


If i can't find worlds, why not just kill then, right? And what better place to start by killing a statistically validated planet along with ~130 other candidates because the exoplanet catalog got its monthly update. Good times.
Apparently TYC 4941 hid its secondary eclipses well enough to escape the validation algorithm's grasps and get its child confirmed. Good thing we caught then in broad daylight with Gaia data.
TYC 4941-622-1's STC was made by Sirius_Alpha.


HD 166620 (PC1)
The Neptune that never was
Status: Disproven

Not everything is sunshine in exohunting. Sometimes you get far in testing all errors and it passed all checks, but it falls apart the second another database shows up. That's what happened to this world. Ahh APF...
No worries, just scream in bed at the thought of this Maunder Minimum star failing on you before sleeping, and then just press on for the next two years. "Just who in the hell do you think i am!"
Oh and it would had been disproven anyway by https://arxiv.org/abs/2308.01348. Eh.


There's some others but i'm withholding then for now. They're mostly part of a thing that's being worked on. I won't go into further details at the moment.

ASASSN-V J190917.06+182837.36
Huh. You are still here...
Status: Unconfirmed (under active study)




Technical infodump:
- ASASSN-V J190917.06+182837.36 is a likely Delta Scuti variable star and A-type subgiant located 1335 parsecs from Earth in the constellation of Sagitta. Its average magnitude is 13.2, has a temperature of about 6000 K, and its about 7.2 times larger than the Sun.
- In 2019, Wey et al. reported that this star was then undergoing a deep dimming event, with a depth of about 1.0 ± 0.1 mag in the Sloan g band. Back then, this was a strange occurence for this star, since it wasn't particularly variable.
- When McCollum & Laine 2019 went on to determine its spectral type and physical parameters, they discovered that it had an extinction of Av = 2.10 +/- 0.12, from an expected Av = 1.5 +/- 0.1. This disparity led the authors of the mentioned study to conclude that "there is a substantial amount of circumstellar extinction" around this star.
- This year, i investigated its archival lightcurve data and found that this star's dimming events are actually periodic (365.94 +/- 0.05 days), lasting about 3 days each. The current leading hypothesis is that, due to its massive radius the depth and duration would imply (Over 5 times the size of the Sun!), ASASSN-V J190917.06+182837.36 is likely orbited by an opaque debris disk surrounding a secondary of unknown mass. This star is about a billion years old by the way.
- In September 2024, this star was actively observed during its transit, however results on that campaign are still upcoming. Its expected that individual features in the disk can be resolved, however.

Alternate hypothesis: Oblate g-darkened binary
(from private comms)

This one is also likely. However, without spectroscopic observations, its difficult to discern between both models.
Note: i made no effort in accurately modelling the secondary in this.

Downloads (CHOOSE ONE!):