Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

28223 results found.

  1. GRB 240418A: Enhanced Swift-XRT position
  2. GRB 240418A: AKO Upper Limit
  3. GRB 240418A: Swift detection of a burst
  4. EP240417a: EP-WXT detection of a fast X-ray transient
  5. GRB 240417A: Fermi GBM Final Real-time Localization
  6. GRB 240415A: Glowbug gamma-ray detection
  7. GRB 240414A: Glowbug gamma-ray detection
  8. GRB 240415B: GECAM-B detection
  9. EP240416A: MASTER optical observations
  10. GRB 240411A: Glowbug gamma-ray detection
  11. EP240416a: EP-WXT detection of a fast X-ray transient
  12. GRB 240415A: Swift/UVOT Detection
  13. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  14. GRB 240415A: Earliest optical followup with the Kinder observations
  15. EP240414a: EP-FXT follow-up observation
  16. GRB 240415A: Enhanced Swift-XRT position
  17. GRB 240415B: Swift ToO observations
  18. GRB 240415B: Swift/BAT-GUANO Correction
  19. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  20. GRB 240415A: OHP/T193 optical observations
  21. GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
  22. GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
  23. GRB 240415A: Mondy optical transient detection
  24. GRB 240414A: Photometric observation from 2.2m CAHA
  25. GRB 240414A: Swift/UVOT Detection
  26. LXT 240402A/GRB 240402B: Swift follow-up observations
  27. GRB 240414B: Fermi GBM Final Real-time Localization
  28. GRB 240414A: AKO Optical Upper Limit
  29. GRB 240415A: Prompt Swift-XRT observations
  30. GRB 240415A: Swift detection of a burst
  31. GRB 240415A: Fermi GBM Final Real-time Localization
  32. GRB 240414A: Swift-XRT refined Analysis
  33. GRB 240414A: Enhanced Swift-XRT position
  34. GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
  35. GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  36. EP240413A: GOTO optical upper limits
  37. GRB 240414A: Skynet Optical Afterglow Observations
  38. EP240413a: possible detection of the X-ray emission with EP-FXT after 14 hours
  39. EP240414a: EP-WXT detection of a fast X-ray transient
  40. IPN triangulation of GRB 240411A
  41. GRB 240414A : MITSuME Akeno optical upper limits
  42. GRB 240414A: Redshift confirmation from GTC/OSIRIS+
  43. EP240413a: EP-WXT detection of a fast X-ray transient
  44. GRB 240414A : OHP/T193 redshift determination
  45. GRB 240414A : OHP/T193 optical counterpart detection
  46. GRB 240414A: Swift detection of a burst
  47. LIGO/Virgo/KAGRA S240413p: Zwicky Transient Facility observations
  48. EP240408a: GSP optical upper limit
  49. GRB 240411B: CrAO/ZTSh optical observations
  50. GRB 240411B: Kinder observations with Lulin observatory
  51. GRB 240411B: HiPERCAM/GTC observation
  52. GRB 240411B: Swift-XRT refined Analysis
  53. IceCube-240412A - IceCube observation of a high-energy neutrino candidate track-like event
  54. GRB 240411B: 1.3m DFOT Optical observations
  55. GRB 240411A: GRBAlpha detection
  56. GRB 240411B: OHP/T193 optical observations
  57. GRB 240405A: Glowbug gamma-ray detection
  58. GRB 240411B: Enhanced Swift-XRT position
  59. GRB 240411B: LCO optical afterglow detection
  60. GRB 240411B: Swift detection of a burst
  61. GRB 240408B: GRBAlpha detection
  62. GRB 240411A: Fermi GBM Final Real-time Localization
  63. EP240408A: MASTER optical observations
  64. EP240408a: GROND detection of a candidate counterpart
  65. EP240408a: Swift follow-up observation
  66. EP240408a: BOOTES-6/DPRT optical upper limit
  67. GRB 240405A: GRBAlpha detection
  68. EP240408a: EP-WXT detection of a fast X-ray transient
  69. Swift Trigger 1220736: detection of 4U 1543-62.
  70. GRB 240408B: AstroSat CZTI detection
  71. IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits
  72. GRB 240408A: Fermi GBM Final Real-time Localization
  73. GRB 240402C: CALET Gamma-Ray Burst Monitor detection
  74. GRB 240407A: Fermi GBM Final Real-time Localization
  75. GRB 240405B: Fermi GBM Final Real-time Localization
  76. GRB 240402C: Glowbug gamma-ray detection
  77. GRB 240405A: Fermi GBM Final Real-time Localization
  78. GRB 240402C: GRBAlpha detection
  79. GRB 240331A: GRBAlpha detection
  80. Swift satellite resumes pointed science observations
  81. GRB 240403B: Glowbug gamma-ray detection
  82. GRB 240403A: Glowbug gamma-ray detection
  83. LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
  84. X-ray transient LXT 240402A: WFST optical upper limits​
  85. Konus-Wind detection of LXT 240402A/GRB 240402B
  86. GRB/FXT 240402B: Kinder optical counterpart candidate
  87. IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
  88. GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
  89. GRB 240403A: Fermi GBM Detection
  90. X-ray transient LXT240402A: AST3-3 optical upper limits
  91. LXT 240402A: EP-FXT detection of the X-ray afterglow
  92. GRB 240404A: Fermi GBM Final Real-time Localization
  93. GRB 240402B: GECAM-C detection
  94. X-ray transient LXT 240402A: LEIA detection
  95. GRB 240402A: Fermi GBM Final Real-time Localization
  96. Transient EP240315a: J-band observations of AT2024eju with WIRC
  97. X-ray transient EP20240331a: MeerLICHT optical upper limits
  98. GRB 240329A: Glowbug gamma-ray detection
  99. GRB 240324A: AstroSat CZTI detection of a short burst
  100. GRB 240331A: AstroSat CZTI detection

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov