Discussion
Loading...

#Tag

  • About
  • Code of conduct
  • Privacy
  • Users
  • Instances
  • About Bonfire
Hacker News
@h4ckernews@mastodon.social  ·  activity timestamp yesterday

Rapid Brightening of 3I/Atlas Ahead of Perihelion

https://arxiv.org/abs/2510.25035

#HackerNews #RapidBrightening #3IAtlas #Perihelion #Astronomy #SpaceScience

arXiv.org

Rapid Brightening of 3I/ATLAS Ahead of Perihelion

Interstellar comet 3I/ATLAS has been approaching its 2025 October 29 perihelion while opposite the Sun from Earth, hindering ground-based optical observations over the preceding month. However, this geometry placed the comet within the fields of view of several space-based solar coronagraphs and heliospheric imagers, enabling its continued observation during its final approach toward perihelion. We report photometry from STEREO-A's SECCHI HI1 and COR2, SOHO's LASCO C3, and GOES-19's CCOR-1 instruments in 2025 September--October, which show a rapid rise in the comet's brightness scaling with heliocentric distance r as r^(-7.5+/-1.0). CCOR-1 also resolves the comet as an extended source with an apparent coma ~4' in diameter. Furthermore, LASCO color photometry shows the comet to be distinctly bluer than the Sun, consistent with gas emission contributing a substantial fraction of the visible brightness near perihelion.
  • Copy link
  • Flag this post
  • Block
Log in

bonfire.cafe

A space for Bonfire maintainers and contributors to communicate

bonfire.cafe: About · Code of conduct · Privacy · Users · Instances
Bonfire social · 1.0.0-rc.3.21 no JS en
Automatic federation enabled
  • Explore
  • About
  • Members
  • Code of Conduct
Home
Login