Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

32508 results found.

  1. GRB 260705B: SVOM/GRM observation
  2. GRB 260706A: Further EP-FXT follow-up observation
  3. GRB 260706A: SVOM/VT optical upper limits
  4. EP260707a (by EP-FXT): NOT optical upper limit
  5. EP260707a is not a real source
  6. EP260707a: LCOGT Optical Upper Limit
  7. EP260707a: TRT optical upper limit
  8. GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
  9. GRB 260705C: Glowbug gamma-ray detection of a short burst
  10. GRB 260706A: SVOM/ECLAIRs refined analysis
  11. GRB 260704A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  12. GRB 260706A: SVOM/GRM observation
  13. GRB 260706A: REM optical/NIR observations
  14. IceCube-260704A: No candidates from the Zwicky Transient Facility
  15. GRB 260706A: LCO optical upper limit
  16. GRB 260706A: EP-FXT follow-up observation
  17. GRB 260706A: Fermi GBM Observation
  18. IceCube-260704A: Upper limits from a search for additional neutrino events in IceCube
  19. IPN triangulation of GRB 260627A
  20. GRB 260705A: SVOM/ECLAIRs refined analysis
  21. GRB 260706A: SVOM detection of a burst
  22. The EP-WXT trigger 01709274014: KAIT confirmation of a stellar flare
  23. IceCube260704A: OHP/T193 optical observations
  24. GRB 260705A: LCO optical upper limits
  25. GRB 260704A: NOT optical upper limits
  26. Fermi GBM Sub-Threshold Detection of GRB 260705A
  27. GRB 260704A: EP-FXT follow-up observation
  28. GRB 260629A: SVOM/GRM observation of a short burst
  29. GRB 260629A: GECAM-A observation of a short burst
  30. IceCube-260704A - IceCube observation of a high-energy neutrino candidate track-like event
  31. GRB 260629A: AstroSat CZTI detection
  32. EP260703a: EP-FXT follow-up observation
  33. Fermi GRB 260703A: Global MASTER-Net observations report
  34. GRB 260610B: VLA detection
  35. GRB 260623A: Glowbug gamma-ray detection
  36. GRB 260614B: ATCA Radio Upper Limits
  37. GRB 260610B / AT2026owq: SAO RAS, CrAO and INASAN further optical observations and light curve
  38. Fermi-LAT Gamma-ray Observations of IceCube-260622A
  39. EP260628a: EP-FXT follow-up observation
  40. Fermi GRB 260628A: Global MASTER-Net observations report
  41. EP260626a: further Liverpool Telescope optical upper limits
  42. EP260626a: EP-FXT follow-up observation
  43. EP260626a: COLIBRÍ optical upper limit
  44. EP260626a: Liverpool Telescope upper limits
  45. Konus-Wind detection of GRB 260623B / EP260623a
  46. EP260623a: TNG NIR afterglow detection
  47. GRB 260618A: Fermi GBM Observation
  48. MASS-Cube (GRID 2.0) detection of GRB 260616B
  49. EP260623a: FTW optical and NIR observations
  50. GRB 260619A: SVOM/ECLAIRs refined analysis
  51. EP260623a: Liverpool Telescope optical observations
  52. Konus-Wind detection of GRB 260618B
  53. GRB 260624A: Fermi GBM Final Real-time Localization (Duplicate Submission)
  54. EP260623a:refined analysis of the EP-WXT and EP-FXT observation
  55. EP260623a: WINTER J-band observations
  56. GRB 260617A: Glowbug gamma-ray detection of a short burst
  57. IceCube-260622A: Upper limits from a search for additional neutrino events in IceCube
  58. IPN triangulation of GRB 260605A
  59. EP260623a: Optical follow-up observations with Kinder
  60. EP260623a: FRAM-ORM detection of the optical afterglow rise, peak and decay
  61. EP260623a: SVOM/VT optical observations
  62. EP260623a: TRT optical observations
  63. EP260623a: REM optical/NIR afterglow detection
  64. EP 260623a: COLIBRÍ optical observations
  65. GRB 260616B/EP260616a: Insight-HXMT/HE detection
  66. EP260623a: OSIRIS+/GTC redshift z = 0.703
  67. EP260623a: Las Cumbres discovery of the optical counterpart
  68. GRB 260614B: EP-FXT follow-up observation
  69. IceCube-260622A - IceCube observation of a high-energy neutrino candidate track-like event
  70. GRB 260618C: SVOM/ECLAIRs detection of a possible burst through on-ground search
  71. EP260618a: Liverpool Telescope optical observations
  72. GRB 260619A: NOT optical observations
  73. GRB 260618B: LCO optical observations
  74. EP260618a: JinShan optical observations
  75. GRB 260616B/EP260616a: SVOM/GRM detection of a burst
  76. GRB 260618B: Fermi GBM Observation
  77. GRB 260619A: TRT optical counterpart confirmation
  78. GRB 260610B: Further GRANDMA Optical Observations and re-brightening detection
  79. GRB 260604B: 239Alferov CubeSat detection
  80. GRB 260604A: 239Alferov CubeSat detection
  81. GRB 260610B: VLT/FORS2 spectroscopic observation suggests the non-thermal nature of the optical rebrightening
  82. GRB 260619A: SVOM/VT optical counterpart confirmation
  83. Fermi-LAT Gamma-ray Observations of IceCube-260610A
  84. GRB 260618B: SVOM/VT optical candidate
  85. GRB 260618B: SVOM/VT optical candidate (duplicate Submission of 45001)
  86. GRB 260619A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  87. Konus-Wind detection of GRB 260617A
  88. GRB 260616B: AstroSat CZTI detection
  89. GRB 260616A: AstroSat CZTI detection
  90. GRB 260616A: SVOM/GRM observation
  91. GRB 260610B/AT2026owq: 1.3m DFOT optical rebrightening detection
  92. GRB 260619A: Kilonova-Catcher optical upper limit
  93. EP260618a: EP-FXT follow-up observation
  94. EP260618a: LCO optical counterpart confirmation
  95. GRB 260617A: CALET Gamma-Ray Burst Monitor detection
  96. EP260618a: COLIBRÍ optical counterpart candidate
  97. GRB 260616A: NuSTAR detection of prompt emission
  98. GRB 260614B: NuSTAR detection of prompt emission
  99. IceCube-260610A: Upper limits from a search for additional neutrino events in IceCube
  100. GRB 260618B: Fermi-LAT 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