Mark Cheung

@markcheung.bsky.social

Astro | Helio | Space Weather | ML Science Director, Space & Astronomy @CSIRO; OMO

Statistically, our current four-transit spectrum of TRAPPIST-1e can also be fit by a flat line (i.e. a featureless spectrum). So we can't rule out a bare rock with these data. There's also the important caveat that an incomplete stellar contamination correction could also imprint spectral features.

The disappearance of Gaia! On 4 March, astronomer Zhuo-Xiao Wang captured this view of the sudden disappearance of ESA’s Gaia spacecraft. Credit: Zhuo-Xiao Wang, CC BY-SA 3.0 IGO Observations performed on 4 March 2025 using an 11-inch telescope from Beijing, China (MPC site code: P13).

👀👀👀 Two exciting preprints today from Aussie institutions and scientists! 🔭☄️ 1. A 41-sec radio pulsar! Slowest pulsar we know about is ~23-secs and then there are these mysterious long-period transients that have rotations periods of mins to hours. This one fits between them!

The discovery of a 41-second radio pulsar PSR J0311+1402 with ASKAP

The emerging population of long-period radio transients (LPTs) show both similarities and differences with normal pulsars. A key difference is that their radio emission is too bright to be powered sol...

arxiv.org

Submitted your PhD in the last three years (but before 2025)? There is an *awesome* prize fellowship for you at Macquarie in Sydney: the Lighthouse Fellowship. If you're into exoplanets, stars, and/or stats, get in touch with me or any of the other faculty and we can talk about it!