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"

15247 results found.

  1. GRB 260924A: Upper limits from a neutrino search with IceCube
  2. GRB260914A: MAO/AZT-22 optical observations
  3. GRB 260924A: COLIBRÍ optical observations
  4. GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  5. EP260924a: EP-FXT follow-up observation
  6. Swift Trigger 1513439 is probably not a GRB
  7. Konus-Wind detection of GRB 260924A
  8. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  9. GRB 260924A: Optical follow-up observations with Kinder
  10. GRB 260924A: SVOM/GRM observation
  11. GRB 260923A: Insight-HXMT/HE detection
  12. EP260924a: EP-WXT detection of an X-ray transient
  13. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  14. GRB 260924A: GROWTH-India Telescope optical observations
  15. Konus-Wind detection of GRB 260922A
  16. Konus-Wind detection of GRB 260921A (correction to GCN 45722)
  17. GRB 260921A: SVOM/GRM observation
  18. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  19. Konus-Wind detection of GRB 260921A (possible merger-origin)
  20. GRB 260924A: Fermi-LAT detection of a bright burst
  21. GRB 260924A: AstroSat CZTI detection
  22. GRB 260920A: SVOM/GRM observation
  23. GRB 260924A: NOT optical counterpart confirmation
  24. GRB 260922A: CALET Gamma-Ray Burst Monitor detection
  25. Trigger_21914: Swift ToO observations
  26. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  27. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  28. ATCA observations of GRB 260909A
  29. GRB 260922A: COLIBRÍ Optical Counterpart Candidate (correction to GCN 45698)
  30. GRB 260922A: COLIBRÍ optical upper limits
  31. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  32. Konus-Wind detection of GRB 260810A
  33. GRB 260918A: SVOM/ECLAIRs refined analysis
  34. GRB 260917C: AstroSat CZTI detection
  35. GRB 260920B/EP260920b: GECAM-B detection of a burst
  36. GRB 260921A: AstroSat CZTI detection
  37. GRB 260921A: Fermi GBM Observation
  38. EP260920b: 2.2m CAHA optical afterglow detection and 10.4m GTC redshift confirmation
  39. GRB 260917B:: SVOM/ECLAIRs refined analysis
  40. The EP-WXT trigger 01709319528 is likely a flaring star
  41. EP260920a: VLT/HAWK-I near-infrared candidate
  42. GRB 260920A: AstroSat CZTI detection
  43. EP260920b: refined analysis of the EP-WXT and EP-FXT observations
  44. EP260920b: COLIBRÍ optical observations
  45. The EP-WXT trigger 01709318601 is likely a flaring star
  46. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  47. EP-WXT detected a brightening of HMXB LS V +44 17
  48. EP260920a: NOT optical upper limits
  49. EP260920a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  50. EP260920a: COLIBRÍ optical upper limits
  51. EP260920a: Update of the LCO optical counterpart candidate
  52. EP260917a: refined analysis of the EP-FXT observations
  53. IceCube-260919A - IceCube observation of a high-energy neutrino candidate track-like event
  54. The EP-WXT trigger 01709318491 is likely a flaring star
  55. EP260806a: Yamaguchi Interferometer radio detections
  56. Konus-Wind detection of GRB 260916B (short/hard)
  57. GRB 260917B: Mondy optical upper limit
  58. EP260917b: EP-WXT detection of an X-ray transient
  59. EP260917A: J-band upper limit with WINTER
  60. GRB 260915A: Swift-XRT afterglow detection
  61. GRB 260918A: SVOM detection of a burst
  62. GRB 260917B: FRAM-Auger optical limits
  63. GRB 260916B: Fermi GBM Detection
  64. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  65. GRB 260917A: Glowbug gamma-ray detection
  66. GRB 260915A: SVOM/ECLAIRs refined analysis
  67. GRB 260917B: SVOM detection of a faint burst
  68. GRB 260914A: 2.2m CAHA optical afterglow detection and 10.4m GTC redshift confirmation
  69. The EP-WXT trigger 01709317235 is likely a flaring star
  70. IceCube-260916A - IceCube observation of a high-energy neutrino candidate track-like event
  71. GRB 260914A: SVOM/GRM observation
  72. GRB 260914A: Mondy and TShAO optical observations
  73. GRB 260914A: SVOM/ECLAIRs refined analysis
  74. GRB 260915A: Swift ToO observations
  75. GRB 260915A: J-band upper limit by SYSU 80cm infrared telescope
  76. GRB 260914A: REM optical/NIR observations
  77. GRB 260914A: VLT/X-shooter observations and redshift confirmation
  78. GRB 260915A: SVOM/VT optical upper limits
  79. GRB 260915A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  80. GRB 260915A: 10.4m GTC deep optical limits
  81. GRB 260915A: SVOM detection of a burst
  82. GRB 260914A: LCO optical observation
  83. GRB 260914A: SVOM/VT optical observation from VHF data
  84. GRB 260914A: SVOM detection of a burst
  85. GRB 260913A: SVOM detection of a faint burst
  86. GRB 260907A: SVOM/GRM observation
  87. GRB 260909A: SVOM/ECLAIRs refined analysis
  88. GRB 260910B: GOTO tentative optical counterpart candidates
  89. GRB 260909A: Swift ToO observations
  90. EP260806a: VLA+ALMA radio detections
  91. GRB 260909A: OHP/T193 z-band upper limit
  92. GRB 260909A: VLT optical and near-infrared upper limits
  93. GRB 260909A: SVOM/GRM observation
  94. GRB 260909A: SVOM detection of a burst
  95. GRB 260903A: Swift ToO observations
  96. GRB 260903A: SVOM/ECLAIRs refined analysis
  97. GRB260903A: Liverpool Telescope optical observations
  98. GRB 260830A: GECAM-B detection of a burst
  99. GRB 260830A: Insight-HXMT/HE detection
  100. GRB 260903A: OHP/T193 optical afterglow 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