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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"

31734 results found.

  1. GRB 221119A: Fermi-LAT detection
  2. GRB 221009A: Japanese VLBI Network observation
  3. GRB 221115B: CALET Gamma-Ray Burst Monitor detection
  4. GRB 221114A: CALET Gamma-Ray Burst Monitor detection
  5. GRB 221115B: LCOGT Optical Upper Limits
  6. Correction to GCN 32646 (GRB 221009A (Swift J1913.1+1946): MeerLICHT observations)
  7. GRB 221115B : MeerLICHT upper limits
  8. GRB 221115A: Fermi GBM detection
  9. GRB 221110A: GRANDMA observations
  10. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 November 9
  11. GRB 221112A: Detection by GRBAlpha
  12. GRB 221110A: COATLI Second-Epoch Upper Limits
  13. GRB 221009A: GRANDMA/Kilonova-Catcher observations
  14. GRB 221110A: GMG upper limit
  15. GRB 221110A: Swift/UVOT Detection and Corrected UVOT Position
  16. GRB 221110A: Swift-BAT refined analysis
  17. GRB 221110A: Swift-XRT refined Analysis
  18. GRB 221110A: VLT/X-shooter redshift
  19. GRB 221110A: COATLI Afterglow detection
  20. GRB 221110A: LCOGT Optical Afterglow Detection
  21. GRB 221009A: Hubble Space Telescope observations
  22. GRB 221107A: Fermi GBM Observation
  23. GRB 221107A: Detection by GRBAlpha
  24. GRB 221009A: Extended Bad Time Intervals for Fermi LAT data
  25. GRB 221107A: Swift/BAT-GUANO detection outside the coded FOV
  26. Correction to GCN 32852 (GRB 221009A: SARA-RM 1m Optical Afterglow Detection)
  27. Fermi-LAT gamma-ray observations of IceCube-221104A
  28. GRB 221029A: CALET Gamma-Ray Burst Monitor detection
  29. GRB 221028A: GRANDMA observations
  30. GRB 221027B: GRANDMA observations
  31. GRB 221028A: Detection by VZLUSAT-2
  32. GRB 221029A: Fermi GBM observation
  33. Konus-Wind detection of GRB 221022C
  34. GRB 221028A: Swift-XRT refined Analysis
  35. GRB 221028A: 1.3m DFOT Optical upper limit
  36. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  37. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  38. GRB 221028A: Correction to GCN 32893 - Fluence and flux are for 50-150 keV
  39. GRB 221028A: AKO Optical Upper Limit
  40. GRB 221028A, Swift-BAT refined analysis
  41. GRB 221027B: Swift-BAT refined analysis
  42. GRB 221029A: Swift/BAT-GUANO detection outside the coded FOV
  43. GRB 221028A: CrAO/ZTSh optical upper limit
  44. GRB 221028A: COATLI Upper Limits
  45. GRB 221028A: HCT optical upper limit
  46. GRB 221028A: AGILE detection
  47. GRB 221027A: AGILE detection
  48. GRB 221028A: MITSuME Okayama optical upper limits
  49. GRB 221028A: LCOGT Optical Upper Limits
  50. GRB 221027B: COATLI Upper Limits
  51. Swift GRB 221028A: Global MASTER-Net observations report
  52. GRB 221028A: GIT optical upper limit
  53. GRB 221027B: Swift/UVOT Upper Limits
  54. Konus-Wind detection of GRB 221017A
  55. Swift GRB 221027B: Global MASTER-Net observations report
  56. GRB 221027B: Swift-XRT refined Analysis
  57. GRB 221027A: Fermi GBM detection
  58. IPN triangulation of GRB 221025A (short)
  59. Konus-Wind detection of GRB 221022B
  60. GRB 221024A: Mondy optical observations
  61. GRB 221027A: Fermi-LAT detection
  62. GRB 221009A: Further Gemini-South Infrared Observations
  63. GRB 221024A: GRANDMA observations
  64. IPN triangulation of GRB 221022C (short)
  65. GRB 221023A: AGILE/GRID analysis
  66. SGR 1935+2154: AstroSat CZTI Detections
  67. GRB 221024A: Swift-BAT refined analysis
  68. GRB 221025A: AstroSat CZTI detection
  69. GRB 221009A: SARA-RM 1m Optical Afterglow Detection
  70. GRB 221025A: Fermi GBM Observation
  71. GRB 221009A: spectroscopic confirmation of SN in LBT spectra
  72. Konus-Wind detection of GRB 221023A
  73. GRB 221024A: Swift/UVOT UV upper limits
  74. GRB 221022A: Swift-XRT observations
  75. GRB 221024A: Swift-XRT refined Analysis
  76. GRB 221023A: Fermi GBM Observation
  77. GRB 221022B: Detection by GRBAlpha
  78. IPN triangulation of GRB 221022B (long)
  79. GRB 221024A: GIT confirmation of the optical afterglow
  80. GRB 221022B: AstroSat CZTI detection
  81. GRB 221022A: Fermi GBM detection
  82. GRB 221022A: Swift ToO observations
  83. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  84. GRB 221023A: Fermi-LAT detection
  85. GRB 221022B: Fermi GBM detection
  86. GRB 221021A: Fermi GBM observation
  87. GRB 221009A: Determination of the black holes mass and spin
  88. GRB 221022A: Swift/BAT-GUANO detection
  89. GRB 221022B: Swift/BAT-GUANO detection outside the coded FOV
  90. GRB 221022B: AGILE detection
  91. GRB 221009A: James Webb Space Telescope Observations
  92. GRB 221009A: Analysis of the initial episode using data of GBM/Fermi and SPI-ACS/INTEGRAL
  93. GRB 221009A: optical observations, SN photometric evidence
  94. GRB 221021A: Swift/BAT-GUANO detection outside the coded FOV
  95. GRB 221020A: Detection by GRBAlpha
  96. GRB 221017A: CALET Gamma-Ray Burst Monitor detection
  97. GRB 221009A: 1.3m DFOT Optical Observations
  98. Fermi GBM trigger 687320613 / 221013100 (GRB 221013B) is not a GRB
  99. GRB221009A: LBT optical imaging
  100. GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow

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