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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').
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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"

32509 results found.

  1. Correction to GCN 32852 (GRB 221009A: SARA-RM 1m Optical Afterglow Detection)
  2. Fermi-LAT gamma-ray observations of IceCube-221104A
  3. GRB 221029A: CALET Gamma-Ray Burst Monitor detection
  4. GRB 221028A: GRANDMA observations
  5. GRB 221027B: GRANDMA observations
  6. GRB 221028A: Detection by VZLUSAT-2
  7. GRB 221029A: Fermi GBM observation
  8. Konus-Wind detection of GRB 221022C
  9. GRB 221028A: Swift-XRT refined Analysis
  10. GRB 221028A: 1.3m DFOT Optical upper limit
  11. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  12. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  13. GRB 221028A: Correction to GCN 32893 - Fluence and flux are for 50-150 keV
  14. GRB 221028A: AKO Optical Upper Limit
  15. GRB 221028A, Swift-BAT refined analysis
  16. GRB 221027B: Swift-BAT refined analysis
  17. GRB 221029A: Swift/BAT-GUANO detection outside the coded FOV
  18. GRB 221028A: CrAO/ZTSh optical upper limit
  19. GRB 221028A: COATLI Upper Limits
  20. GRB 221028A: HCT optical upper limit
  21. GRB 221028A: AGILE detection
  22. GRB 221027A: AGILE detection
  23. GRB 221028A: MITSuME Okayama optical upper limits
  24. GRB 221028A: LCOGT Optical Upper Limits
  25. GRB 221027B: COATLI Upper Limits
  26. Swift GRB 221028A: Global MASTER-Net observations report
  27. GRB 221028A: GIT optical upper limit
  28. GRB 221027B: Swift/UVOT Upper Limits
  29. Konus-Wind detection of GRB 221017A
  30. Swift GRB 221027B: Global MASTER-Net observations report
  31. GRB 221027B: Swift-XRT refined Analysis
  32. GRB 221027A: Fermi GBM detection
  33. IPN triangulation of GRB 221025A (short)
  34. Konus-Wind detection of GRB 221022B
  35. GRB 221024A: Mondy optical observations
  36. GRB 221027A: Fermi-LAT detection
  37. GRB 221009A: Further Gemini-South Infrared Observations
  38. GRB 221024A: GRANDMA observations
  39. IPN triangulation of GRB 221022C (short)
  40. GRB 221023A: AGILE/GRID analysis
  41. SGR 1935+2154: AstroSat CZTI Detections
  42. GRB 221024A: Swift-BAT refined analysis
  43. GRB 221025A: AstroSat CZTI detection
  44. GRB 221009A: SARA-RM 1m Optical Afterglow Detection
  45. GRB 221025A: Fermi GBM Observation
  46. GRB 221009A: spectroscopic confirmation of SN in LBT spectra
  47. Konus-Wind detection of GRB 221023A
  48. GRB 221024A: Swift/UVOT UV upper limits
  49. GRB 221022A: Swift-XRT observations
  50. GRB 221024A: Swift-XRT refined Analysis
  51. GRB 221023A: Fermi GBM Observation
  52. GRB 221022B: Detection by GRBAlpha
  53. IPN triangulation of GRB 221022B (long)
  54. GRB 221024A: GIT confirmation of the optical afterglow
  55. GRB 221022B: AstroSat CZTI detection
  56. GRB 221022A: Fermi GBM detection
  57. GRB 221022A: Swift ToO observations
  58. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  59. GRB 221023A: Fermi-LAT detection
  60. GRB 221022B: Fermi GBM detection
  61. GRB 221021A: Fermi GBM observation
  62. GRB 221009A: Determination of the black holes mass and spin
  63. GRB 221022A: Swift/BAT-GUANO detection
  64. GRB 221022B: Swift/BAT-GUANO detection outside the coded FOV
  65. GRB 221022B: AGILE detection
  66. GRB 221009A: James Webb Space Telescope Observations
  67. GRB 221009A: Analysis of the initial episode using data of GBM/Fermi and SPI-ACS/INTEGRAL
  68. GRB 221009A: optical observations, SN photometric evidence
  69. GRB 221021A: Swift/BAT-GUANO detection outside the coded FOV
  70. GRB 221020A: Detection by GRBAlpha
  71. GRB 221017A: CALET Gamma-Ray Burst Monitor detection
  72. GRB 221009A: 1.3m DFOT Optical Observations
  73. Fermi GBM trigger 687320613 / 221013100 (GRB 221013B) is not a GRB
  74. GRB221009A: LBT optical imaging
  75. GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow
  76. GRB 221017A: Swift-XRT observations
  77. Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)
  78. GRB 221009A: TNG NIR detection
  79. GRB 221009A: BOAO NIR detections
  80. GRB 221009A X-ray light-curve and the indication of TeV light-curve
  81. AGILE detection of a burst from SGR J1935+2154 reported by VZLUSAT-2
  82. GRB 221009A: Spectroscopic detection of emerging SN features
  83. GRB 221009A: Continued LDT Afterglow Monitoring
  84. GRB 221013B: Swift/BAT-GUANO detection
  85. SGR 1935+2154: Bursting activity detected by VZLUSAT-2
  86. AGILE detection of the 2022 October 17 burst from SGR J1935+2154 reported by Konus-Wind
  87. GRB 221009A: GRANDMA observations
  88. SGR 1935+2154: Detection by GRBAlpha
  89. GRB 221009A: Medicina Radio Telescope observations
  90. GRB 221017A: Swift ToO observations
  91. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  92. GRB 221009A: Second epoch of NuSTAR data
  93. IPN triangulation of GRB 221017A (long)
  94. GRB 221016A: Swift-BAT refined analysis
  95. GRB 221016A: Swift/UVOT Detection
  96. GRB 221016A: Swift-XRT refined Analysis
  97. Konus-Wind detection of GRB 221016A
  98. GRB 221016A: Fermi GBM observation
  99. GRB 220926B: Detection by GRBAlpha
  100. GRB 221016A: z-band upper limit, possible afterglow brightening

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