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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"

28696 results found.

  1. Alert from the HAWC Burst Monitor HAWC-200814A
  2. IceCube200806A: No significant detection in HAWC
  3. GRB 200809B: Fermi GBM detection
  4. Fermi GRB 200809B: Global MASTER-Net observations report
  5. GRB 200809B: Swift-XRT afterglow detection
  6. GRB 200809B: MAXI/GSC detection
  7. GRB 200809B: Swift ToO observations
  8. GRB 200809B: AstroSat CZTI detection
  9. GRB 200809B: Swift/BAT-GUANO detection and arcminute localization
  10. GRB 200808A: AGILE detection
  11. GRB 200806A: CALET Gamma-Ray Burst Monitor detection
  12. Fermi GRB 200808A: Global MASTER-Net observations report
  13. GRB 200806A: Nanshan/NEXT optical upper limit
  14. IPN triangulation of GRB 200805A (short)
  15. GRB 200806A: CAHA optical afterglow confirmation
  16. GRB 200803A: Chilescope optical upper limit
  17. GRB 200806A: VIRT optical observations
  18. GRB 200806A: Swift-BAT refined analysis
  19. GRB 200806A: Swift/UVOT Possible Detection
  20. GRB 200806A: Swift-XRT refined Analysis
  21. Fermi-LAT Gamma-ray Observations of IceCube-200806A
  22. CGBM-SPI-ACS triangulation of short GRB 200805A
  23. GRB 200806A: AbAO optical upper limit
  24. GRB 200805A: CALET Gamma-Ray Burst Monitor detection of a short burst
  25. GRB 200806A: AstroSat CZTI detection
  26. GRB 200806A: MITSuME Akeno optical upper limits
  27. IceCube-200806A: Upper limits from Fermi-GBM Observations
  28. Swift GRB 200806A: Global MASTER-Net observations report
  29. GRB 200803B: MASTER possibly OT discovery
  30. GRB 200803A: AstroSat CZTI detection
  31. GRB 200803A: Fermi GBM detection
  32. GRB 200803A: Swift-XRT afterglow detection
  33. Fermi GRB 200803B: Global MASTER-Net observations report
  34. GRB 200803A: Fermi-LAT detection
  35. GRB 200803A: MASTER optical counterpart discovery
  36. GRB 200803A: Tiled Swift observations
  37. Fermi GRB 200803A: Global MASTER-Net observations report
  38. GRB 200801B: AstroSat CZTI detection
  39. Fermi GRB 200801B: Global MASTER-Net observations report
  40. Fermi GRB 200802A: Global MASTER-Net observations report
  41. AX J1846.4-0258: Swift-BAT refined analysis
  42. Konus-Wind detection of GRB 200729A
  43. Fermi GRB 200801A: Global MASTER-Net observations report
  44. GRB 200729A: RT-22 observations at 36.8 GHz
  45. GRB 200729A: VLA Observations
  46. GRB 200729A: Nanshan/NEXT optical upper limit
  47. GRB 200729A: Swift-BAT refined analysis
  48. GRB 200729A: further analysis of the NOT data
  49. GRB 200729A: Swift/UVOT Upper Limits
  50. GRB 200729A: Swift-XRT refined Analysis
  51. Fermi-GBM Sub-Threshold candidate for GRB 200729A
  52. GRB 200729A: Pan-STARRS pre-explosion source detection
  53. GRB 200729A: Spitzer archival source detection
  54. GRB 200729A: TNG NIR upper limits
  55. GRB 200729A: NOT optical upper limits
  56. Swift GRB 200729A: Global MASTER-Net observations report
  57. IceCube GCN Notice 134327_10548129 retraction
  58. GRB 200723A: ATLAS observations of GOTO candidate AT2020qer
  59. GRB 200723A: Swift ToO observations
  60. GRB 200723A: GOTO candidate afterglow and host galaxy
  61. Fermi GRB 200723A: Global MASTER-Net observations report
  62. GRB 200716C: Kitab optical observations
  63. GRB 200716C: CAHA optical observation // Anomalous light curve behavior?
  64. GRB 200716C: CrAO, Terskol, Assy-Turgen optical observations
  65. GRB 200714E: Swift-XRT afterglow detection
  66. GRB 200716C: FRAM-ORM afterglow detection
  67. Konus-Wind observation of GRB 200716C: correction to GCN 28147
  68. Konus-Wind observation of GRB 200716C
  69. GRB 200716C: VIRT optical detection.
  70. GRB 200716C: Insight-HXMT/HE detection
  71. AMON IC_HAWC 170720: Correction to ANTARES GCN 28142
  72. Fermi GRB 200718A: Global MASTER-Net observations report
  73. AMON IC_HAWC 170720: No Neutrino Counterpart detected with ANTARES
  74. GRB 200716C: CALET Gamma-Ray Burst Monitor detection
  75. GRB 200716C: Optical observations from HCT
  76. GRB 200716B: Insight-HXMT/HE detection
  77. GRB 200716C: Swift-BAT refined analysis
  78. GRB 200716C: Fermi GBM detection
  79. Fermi GRB 200716A: Global MASTER-Net observations report
  80. GRB 200716C: AGILE/MCAL detection
  81. GRB 200716C: possible host galaxy from the SDSS
  82. GRB 200716C: Swift-XRT refined analysis correction
  83. GRB 200716C: Fermi-LAT detection
  84. GRB 200716C: Swift-XRT refined Analysis
  85. GRB 200522A: HST NIR counterpart confirmation
  86. Swift GRB200716C: Global MASTER-Net OT detection
  87. IPN triangulation of GRB 200716A
  88. GRB 200716A: Fermi GBM detection
  89. Fermi GRB 200716B: Global MASTER-Net observations report
  90. GRB 200716B: AstroSat CZTI detection
  91. GRB 200716A: AstroSat CZTI detection
  92. GRB 200716A: AGILE detection
  93. GRB 200715A: Swift-XRT afterglow detection
  94. GRB 200715A: Swift ToO observations
  95. GRB 200714E: Fermi GBM observation
  96. GRB 200714E: Swift-XRT observations
  97. Fermi GRB 200714E: Global MASTER-Net observations report
  98. GRB 200714E: AGILE detection
  99. GRB 200714E: Swift ToO observations
  100. GRB 200714E: Swift/BAT-GUANO detection and arcminute localization

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