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"

29074 results found.

  1. IceCube Alert 260217A: Global MASTER-Net observations report
  2. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  3. GRB 260217A: Fermi GBM Final Localization
  4. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  5. sb26021801: SVOM detection of a long faint X-ray transient
  6. The EP-WXT trigger 01709258455 is likely a flaring star
  7. EP-WXT 01709258455: NOT optical upper limits
  8. EP260214b: 1.3m DFOT optical upper limit
  9. Konus-Wind detection of GRB 260212A
  10. GRB 260208A: AbAO and Terskol optical upper limits
  11. GRB 260208A: continued Mondy optical observations
  12. IPN triangulation of GRB 260212A
  13. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  14. GRB 260213A: GECAM-B observation of a short burst
  15. GRB 260216A: Fermi Gamma-ray Burst Monitor trigger 792969362/260216886 is not a GRB
  16. GRB 260216A: Fermi GBM Final Real-time Localization
  17. EP260214b: Liverpool Telescope optical observations
  18. EP260214b: Optical upper limit with Kinder observations
  19. EP260214a: Optical upper limits with Kinder observations
  20. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  21. EP260214b: DDOTI Optical Detection
  22. EP260214b: GROWTH-India Telescope optical upper limit
  23. EP260214a: VLT near-infrared observation
  24. EP260214b: SVOM/VT optical observation
  25. EP260214a: NOT optical upper limits
  26. EP260214a: COLIBRÍ optical upper limits
  27. EP260214b: OHP/T120 optical observations
  28. EP260214b: LCO optical counterpart detection
  29. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  30. GRB 260211A: SVOM/VT optical counterpart
  31. EP260214b: COLIBRÍ optical observations
  32. EP260214a: SVOM/VT optical upper limits
  33. EP260214b: NOT optical counterpart detection
  34. EP260214a: Global MASTER-Net observations report
  35. GRB 260212A: AstroSat CZTI detection
  36. GRB 260212A: Fermi GBM Observation
  37. EP260213a: Global MASTER-Net observations report
  38. EP260213a: COLIBRÍ optical upper limits
  39. GRB 260212A: GECAM-B observation
  40. EP260213a: Optical upper limits with Kinder observations
  41. EP260213a: SVOM/VT optical upper limit
  42. EP260213a: NUTTelA-TAO Early Optical Limits
  43. EP260213a: SVOM/C-GFT upper limit
  44. EP/WXT 01709258378: NOT optical upper limits
  45. GRB 260212A: SVOM/GRM observation of a long burst
  46. GRB 260213B: Fermi GBM Final Localization
  47. GRB 260213B: BALROG localization (Fermi Trigger 792697214 / GRB 260213736)
  48. GRB 260211A - SVOM/ECLAIRs refined analysis
  49. GRB 260204A: SVOM/ECLAIRs refined analysis
  50. GRB 260213A: Fermi GBM Final Localization
  51. GRB 260211A: EP-FXT follow-up observation
  52. GRB 260211A: SVOM/VT optical observation
  53. GRB 260212A: Glowbug gamma-ray detection
  54. GRB 260211A: GOTO optical upper limit
  55. Fermi GRB 260212A: Global MASTER-Net observations report
  56. GRB 260212A: Fermi GBM Final Real-time Localization
  57. GRB 260210A: SVOM/GRM observation
  58. Fermi GBM Sub-Threshold Detection of GRB 260211A
  59. Konus-Wind detection of GRB 260207B
  60. GRID detection of GRB 260207B
  61. GRB 260211A: LCO optical upper limits
  62. GRB260131A/B: 3.6m DOT Optical Observations
  63. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  64. Fermi trigger No 792537871: Global MASTER-Net observations report
  65. GRB 260211A: SVOM detection of a burst
  66. GRB 260208A: Swift UVOT detection
  67. Konus-Wind detection of GRB 260127B
  68. EP260209a: COLIBRÍ optical upper limit
  69. Fermi GRB 260210C: Global MASTER-Net observations report
  70. EP260209a: LCO optical upper limits
  71. EP260210a: Global MASTER-Net observations report
  72. EP260210a: refined analysis of the EP-FXT observation
  73. EP260209a: Global MASTER-Net observations report
  74. GRB 260208A: LCO detection of the optical counterpart
  75. EP260210a: Optical upper limits with Kinder observations
  76. IPN triangulation of GRB 260207B (short/hard with EE)
  77. GRB 260210C: Fermi GBM Final Real-time Localization
  78. GRB 260210B: Fermi GBM Final Real-time Localization
  79. EP260210a: SVOM/VT optical upper limit
  80. GRB 260208C: AstroSat CZTI detection
  81. EP260210a: COLIBRÍ optical upper limit
  82. EP260210a: SVOM/C-GFT upper limit
  83. GRB 260208B: refined analysis of the EP-FXT observation
  84. GRB 260207B: AstroSat CZTI detection
  85. GRB 260208C: SVOM/GRM observation
  86. GRB 260208B: AstroSat CZTI detection of a bright long burst
  87. GRB260208A: Liverpool Telescope optical follow-up observations
  88. GRB 260208A: Glowbug gamma-ray detection
  89. GRB 260208A: NuSTAR detection of prompt emission
  90. GRB 260208A: Fermi GBM Observation
  91. Fermi GRB 260209A: Global MASTER-Net observations report
  92. GRB 260208B: Swift-XRT observations
  93. GRB 260131A/B: continued Mondy optical observations
  94. GRB 260204A: Swift/UVOT Upper Limits
  95. GRB 260208B: COLIBRÍ optical observations
  96. GRB 260208A: Mondy optical observations
  97. GRB 260208A: 1.3m DFOT optical detection
  98. GRB 260208A: COLIBRÍ optical observations
  99. GRB 260208B: EP-FXT observation
  100. GRB 260208A: NOT spectroscopic redshift z = 2.36

Advanced

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