#tesstuesday — Public Fediverse posts

You may have forgotten about #TESStuesday! But rest assured... so did I actually. Anyway, Panetier et al. yesterday presented power spectra of some very bright (G<6ish) stars which are solar-like oscillators, from TESS data:

https://arxiv.org/abs/2605.14713

Though I'd question the significance of some detections, there are plenty of great detections in Appendix B. Here's υ Cep, which is known to be a binary star. I'm not sure if all these oscillations are certainly from one star.

#astronomy

This #TESStuesday, it looks like a new high-level science product (HLSP) for TESS is coming to MAST soon: TEQUILA, by Ogunwale et al. 🌵

https://arxiv.org/abs/2511.19313

This looks like a surprisingly simple but effective differential imaging + simple aperture photometry pipeline. Light curves aren't available yet so I'll be watching out to maybe have a look for some red giants to see how it fares with solar like oscillators.

#astronomy #astrodon

It's still #TESStuesday! And today's there's some neat #asteroseismology.

You may have heard of the "Methusaleh star", which is very old but I honestly don't think was ever a challenge to the accepted age of the Universe. But this study of the oscillations based on TESS data is nevertheless interesting because it's very poor in metals relative to other asteroseismic targets, and shows that our rough rules for oscillation properties seem to deviate at low metallicity.

https://arxiv.org/abs/2510.11532

Yo dawg, we herd u like eclipses so we put eclipses in yo eclipses so u can eclipse while u eclipse

Crudely (!) adapted from Fig. 9 of

Borkovits et al., "Ten new, ultracompact triply eclipsing triple star systems", accepted in A&A

https://arxiv.org/abs/2510.04565

#TESStuesday #astronomy

I might incur 13.7 days of bad luck for sharing a non-TESS light curve on #TESStuesday but this multi-band light curve from the brand new Vera C. Rubin Observatory's commissioning data is too good. 🤩

This is a distant (16.6kpc), faint (18th magnitude) SX Phe variable but the light curve has the unmistakable shape (in the optical g band) of a δ Sct/SX Phe variable.

https://iopscience.iop.org/article/10.3847/2515-5172/adeab0

#astronomy #astrodon #asteroseismology

Perhaps, like me, you enjoy the light curves of eclipsing binaries *and* pulsating stars, so for #TESStuesday, have a look at Alexios Liakos's "Asteroseismology of four eccentric double-lined spectroscopic eclipsing binaries". Some of the components are δ Sct variables, some are γ Dor variables, and some are both! 🤩

https://arxiv.org/abs/2506.14395

#astronomy #astrodon

I've foolishly decided to try to keep up some #TESStuesday momentum. I think today's a bit of a bonanza: "The TESS Ten Thousand Catalog" by Kostov et al.

https://arxiv.org/abs/2506.05631

In particular, have a look at the highlighted interesting systems in §5.4 (Figs 30–39) for some fascinating eclipse behaviour: precession, evolving starspots, general craziness (that's you, TIC 114936199) and more. 🤩

#astronomy #astrodon

You may have forgotten about #TESStuesday but I haven't (well, not entirely)! And it's a good excuse to bring up what might be the craziest eclipse lightcurve I've seen. Powell et al. figured it out back in 2022 but it's news to me and perhaps you too:

https://aasnova.org/2022/11/23/four-stars-many-eclipses/

#astronomy

I hope you haven't forgotten about #TESStuesday! Inspired by Lewis et al.'s new detailed study of its debris disk, here's the Sector 12 timeseries and amplitude spectrum of HD 156623, which shows clear "high-order" δ pulsations.

https://arxiv.org/abs/2407.15986

Instead of posting light curves this #TESStuesday, I'll draw your attention to NASA's call for community input—in the form of 1-2 paragraph science "pitches" due this Friday, June 14—on TESS's extended missions.

Note also the document describing some potential new observing modes—

⏱️📸— 2-second cadence target pixel files

☀️ 🌍 🛰️— 54-day "sectors"

—and mentioning that 60% of >1700 peer-reviewed TESS publications are general astrophysics, rather than exoplanets. 😉

https://heasarc.gsfc.nasa.gov/docs/tess/notice-of-call-for-community-input-into-the-tess-extended-mission-planning.html

This #TESStuesday, I offer the eclipsing binary TY Pyx. Nothing at all made me think "I don't think I've ever looked at variables in Pyxis", so I grabbed something at random from the GCVS. So here it is, with very spotty out-of-eclipse variations also make it an RS CVn variable. Spectral type is G5IV+G5IV so I tried my hand at finding solar-like oscillations but I didn't find anything (though I didn't try *that* hard).

#asteroseismology

Still enough time this #TESStuesday to point to a recent article on arXiv by Liu & Qian on TESS light curves for seven cataclysmic variables. I love TESS (and previously K2) used for work in unexpected domains. Many of these objects have baseline brightnesses around 16th magnitude!

https://arxiv.org/abs/2405.11843

For #TESStuesday, I recently came across Tobin et al.'s discovery of a substellar companion around the γ Dor variable HIP 39017 (= V769 Mon). The TESS light curve (some of Sector 7 shown) does *not* disappoint.

https://arxiv.org/abs/2403.04000

#asteroseismology

For #TESStuesday, nothing in particular prompted me to have a look at the light curve of the F2 dwarf η Cru after a recent preprint analysed its debris disk:

https://arxiv.org/abs/2404.04508

Based on the spectral type and amplitude spectrum, it looks like either a γ Dor variable or rapid rotator. I was wishing it was the former but I accept probably the latter, with a rotation period around 1.05d. (That'd make the inclination implied by vsini ~ 46 km/s consistent with the inclination of the disk.)

For #TESStuesday, I offer you this study by Marcadon & Prša of *eclipse* timing variations in TESS light curves of known eclipsing binaries. You might've heard of *transit* timing variations (TTVs) and this is the same idea. Triple star systems are interesting for various reasons, including how (and how often) they might form, as well as what they might evolve into (it naturally gets even more complicated than with binaries...).

https://arxiv.org/abs/2403.07694

#astronomy #astrodon

For #TESStuesday, I bring the rapidly-oscillating peculiar A (roAp) star γ Equ, whose pulsations I didn't know about until I saw this paper by Järvinen et al. in which they study the magnetic splitting (Zeeman effect) in its spectrum.

The TESS amplitude spectrum (data in Sector 55) is a textbook roAp star, with a strong peak at a period of ~116 c/d = a period of ~12.5 minutes.

https://arxiv.org/abs/2401.16966

#asteroseismology

It's still #TESStuesday and I wanted to highlight a series of papers by John Southworth in The Observatory, titled "Rediscussion of Eclipsing Binaries". He's using TESS data to reanalyse known eclipsing binary systems, most recently the ~F1V+F2IV binary GK Dra. Here's his amplitude spectrum after removing the eclipses, clearly showing pulsations (probably δ Sct+γ Dor). The main period is attributed to the secondary but the primary could be pulsating too!

https://arxiv.org/abs/2401.13396

#astronomy

There's still time for #TESStuesday! I'll highlight a recently accepted paper by Potranov et al. with Doppler Imaging of the α² CVn variable MX Tra. By taking lots of high-resolution spectra over the ~2.16d rotation period, they infer maps of the surface distributions of various elements. The TESS data gets a shoutout too!

I always wonder how precise the inferred maps are but the principle is very cool.

https://arxiv.org/abs/2312.09594

#TESStuesday is not forgotten! On arXiv today, Sepulveda et al. show amplitude spectra from TESS of the definitely-δ-Sct-variable HIP 65426 (HD 116434), whose orbiting planet was the to be imaged by JWST (Carter et al., 2023). It rotates crazy fast (jargon, sorry): vsini ≈ 280 km/s, rotation period ~7.3h so the echelle diagram lacks any patterns that we recognise (yet?).

https://arxiv.org/abs/2312.05310

#asteroseismology #astronomy

Just missed another #TESStuesday but here are the clear solar-like oscillations in β Hyi anyway, using 20-second data from TESS Sector 67. TESS's PI recently spoke at a conference in Hawai'i and revealed that the spacecraft—already 5 years into its mission—could last *decades*...

#asteroseismology

Instead of light curves, I'll use this #TESStuesday to remind you that TESS started science operations #onthisday, five years ago! 🛰️

It's currently set to continue until October 2024 as part of its second mission extension, but AFAIK it should be able to keep going for many years beyond that, as long as NASA keeps funding its mission.

And we still won't be able to keep up with the data.

https://www.nasa.gov/feature/goddard/2018/nasa-s-tess-spacecraft-starts-science-operations

Another #TESStuesday, another old SIMBAD tab closed. This time it's the metal-poor subgiant HD 59984. This is a slightly (5-point) smoothed power spectrum for the 20s cadence data in Sector 34, with clear oscillations around ~1100 μHz. Huber et al. (2022) showed how (and why) this "fast" cadence data is better for bright solar-like oscillators. Here too, the the oscillations aren't nearly as clear in the data at 120s cadence.

#asteroseismology

http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+59984

https://ui.adsabs.harvard.edu/abs/2022AJ....163...79H

This #TESStuesday, I'm closing a tab with a mysterious SIMBAD search for HD 47874. Here's the amplitude spectrum for TESS Sectors 6 & 7. It appears to be a (blended?) eclipsing binary (hence the dense, low-frequency comb) that's also a high-order δ Scuti pulsator.

#asteroseismology

simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+47874

For #TESStuesday, it's back to closing old SIMBAD tabs. In this case, at least I remember why I ever searched this star! χ Her is a subgiant and depleted in metals compared to the Sun. Its solar-like oscillations are nice and clear in the TESS data for sectors 50 & 51. #asteroseismology

http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=chi+her

For #TESStuesday, how about quadruple star system TIC 219006972, which comprises two eclipsing binaries and is studied in detail in a paper by Kostov et al. on arXiv today:

https://arxiv.org/abs/2303.14275

The inner and outer orbits are all aligned, though I guess sufficiently misaligned (just a little) so that the components of A don't eclipse the components of B?

This #TESStuesday is more than just another closed tab. I spent some evenings last week selecting different eclipsing binaries for and adding some actual descriptions to my (still quite rough) Atlas of TESS Light Curves:

https://warrickball.gitlab.io/tess-atlas/eb/ea.html

Now featuring

- Algol (β Per),
- Thuban (α Dra),
- γ Per,
- ζ Phe,
- HW Vir

as well as oscillating Algol variables

- RZ Cas,
- AB Cas,
- Y Cam and
- AS Eri!

Hope to chip away at descriptions soon.

I'm still closing tabs for #TESStuesday. Here's HD 11964, a G9 subgiant, known to host two planets and a distant M-dwarf companion. It's also a solar-like oscillator, given the usual comb of peaks in this lightly-smooth power density spectrum of 20s cadence data from Sector 30.

http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+11964

Still just enough time this #TESStuesday to close another tab with a mysterious SIMBAD query. No idea why I looked up TIC 159387771 but the amplitude spectrum shows it's a "high-order" δ Scuti variable. Lots of pressure modes with radial order < 10ish.

http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=TIC+159387771

@warrickball
I love #TESStuesday!!!! Thank you for helping keep the tradition alive

I'll continue to keep #TESStuesday alive by closing tabs on SIMBAD searches that I don't fully remember making. Here's HD 59984, a metal-poor G0 subgiant. I think I looked these up while on a tangent about studying the Milky Way's formation using these stars, for which Fuhrmann & Chini (2021) gave a sample.

The solar-like oscillations are crystal clear in TESS's 20s data from Sector 34.

#asteroseismology

http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+59984