StarXiv: a podcast discussing the latest astronomy papers · Michelle and Payel

Episode 29 - Exploding stars, carbon stars, and starbursting pseudo little red dots

·32 min·2 clips

Pseudo LRD nom has a 2.9 million-solar-mass black hole and about 0.7 solar masses per year of star formation.

1. StarXiv episode 29 ranges from type Ia supernova cosmology to Thamnos, the Ring Nebula, and pseudo little red dots. 2. Michelle and Nicole host the episode, and Nicole returns after a long break while Michelle leads the discussion of recent astronomy papers. 3. The episode asks whether recent papers change what astronomers think about dark energy, halo substructure, planetary nebulae, and high-redshift compact galaxies. 4. Phil Wiseman et al. from Southampton are discussed first because their MNRAS paper responds to a 2025 claim about supernova trends and cosmology. 5. The hosts explain that type Ia supernovae are standardised before distance measurement and that dark energy was discovered through supernova distances. 6. The response paper adds g-host corrections and survey-selection corrections that were missing from the earlier analysis. 7. After those corrections, the apparent host-age trend in the supernova sample becomes insignificant. 8. The authors also compare early-type and late-type galaxies using DES Year 5 data and find no statistical difference. 9. Nicole then covers Renjing Xie et al.’s HRGO2 paper on low-energy retrograde dynamically tagged groups in the Milky Way halo. 10. The sample contains 35 stars from RG8 and RG9, observed with Subaru, Magellan, CFHT, and VLT spectroscopy. 11. Their chemical abundances indicate that RG8 and RG9 are probably one structure rather than two separate ones. 12. The metallicity distribution peaks at [Fe/H] = -2.1, with a secondary peak at [Fe/H] = -1.5 that the hosts attribute to Milky Way contamination. 13. The inferred progenitor mass is about 10^6 solar masses, and the chemistry shows no detectable alpha knee. 14. The discussion compares the retrograde structure with the Cetus stream and suggests an earlier merger than the Cetus progenitor. 15. Michelle’s weave paper on NGC 6720 uses 547 fibers and JWST comparison to study the Ring Nebula. 16. The most unusual result is a narrow iron feature around 4,227 angstroms that extends about 50 arcseconds. 17. The feature does not match a clean jet interpretation because the velocity field does not show the expected large difference between its ends. 18. The tone is conversational and survey-driven, with each paper summarized through specific methods, numbers, and named datasets. 19. Listeners who follow supernova cosmology, Milky Way archaeology, and JWST-era galaxies will get the most from it. 20. Listeners who want only one topic or a very short single-paper segment may skip it.

As heard by us

Supernovae, merger history, and WEAVE get a close, slightly unruly read.

Episode 29 keeps its attention on the science, moving from the response to Still Accelerating Type 1a Supernova Cosmology: Post-Galaxy Age Evolution to the WEAVE image spectroscopy paper on NGC 6720, then to a retrograde Milky Way system that may have merged even earlier than…

Read the full review in PlayNext →

Why you'd press play

You get Type 1a supernova cosmology, a merger rethink, and a WEAVE detour without the polish tax.

Read the full recommendation in PlayNext →

Listen to the show on

Apple Podcasts Spotify

Play clips from this episode More from StarXiv: a podcast discussing the latest astronomy papers