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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"

28705 results found.

  1. GRB 200819A: MITSuME Ishigaki optical upper limits
  2. GRB 200729A: Lowell Discovery Telescope observations
  3. GRB 200819A: MITSuME Akeno optical upper limits
  4. GRB 200819A: Kitab, TSHAO optical upper limit
  5. Swift GRB 200819A: Global MASTER-Net observations report
  6. Swift Trigger 990358 is due to detector noise
  7. Swift Trigger 989458 is due to detector noise
  8. Fermi GRB 200817A: Global MASTER-Net observations report
  9. GRB 200815A: CALET Gamma-Ray Burst Monitor detection of a short burst
  10. Alert from the HAWC Burst Monitor HAWC-200814A
  11. IceCube200806A: No significant detection in HAWC
  12. GRB 200809B: Fermi GBM detection
  13. Fermi GRB 200809B: Global MASTER-Net observations report
  14. GRB 200809B: Swift-XRT afterglow detection
  15. GRB 200809B: MAXI/GSC detection
  16. GRB 200809B: Swift ToO observations
  17. GRB 200809B: AstroSat CZTI detection
  18. GRB 200809B: Swift/BAT-GUANO detection and arcminute localization
  19. GRB 200808A: AGILE detection
  20. GRB 200806A: CALET Gamma-Ray Burst Monitor detection
  21. Fermi GRB 200808A: Global MASTER-Net observations report
  22. GRB 200806A: Nanshan/NEXT optical upper limit
  23. IPN triangulation of GRB 200805A (short)
  24. GRB 200806A: CAHA optical afterglow confirmation
  25. GRB 200803A: Chilescope optical upper limit
  26. GRB 200806A: VIRT optical observations
  27. GRB 200806A: Swift-BAT refined analysis
  28. GRB 200806A: Swift/UVOT Possible Detection
  29. GRB 200806A: Swift-XRT refined Analysis
  30. Fermi-LAT Gamma-ray Observations of IceCube-200806A
  31. CGBM-SPI-ACS triangulation of short GRB 200805A
  32. GRB 200806A: AbAO optical upper limit
  33. GRB 200805A: CALET Gamma-Ray Burst Monitor detection of a short burst
  34. GRB 200806A: AstroSat CZTI detection
  35. GRB 200806A: MITSuME Akeno optical upper limits
  36. IceCube-200806A: Upper limits from Fermi-GBM Observations
  37. Swift GRB 200806A: Global MASTER-Net observations report
  38. GRB 200803B: MASTER possibly OT discovery
  39. GRB 200803A: AstroSat CZTI detection
  40. GRB 200803A: Fermi GBM detection
  41. GRB 200803A: Swift-XRT afterglow detection
  42. Fermi GRB 200803B: Global MASTER-Net observations report
  43. GRB 200803A: Fermi-LAT detection
  44. GRB 200803A: MASTER optical counterpart discovery
  45. GRB 200803A: Tiled Swift observations
  46. Fermi GRB 200803A: Global MASTER-Net observations report
  47. GRB 200801B: AstroSat CZTI detection
  48. Fermi GRB 200801B: Global MASTER-Net observations report
  49. Fermi GRB 200802A: Global MASTER-Net observations report
  50. AX J1846.4-0258: Swift-BAT refined analysis
  51. Konus-Wind detection of GRB 200729A
  52. Fermi GRB 200801A: Global MASTER-Net observations report
  53. GRB 200729A: RT-22 observations at 36.8 GHz
  54. GRB 200729A: VLA Observations
  55. GRB 200729A: Nanshan/NEXT optical upper limit
  56. GRB 200729A: Swift-BAT refined analysis
  57. GRB 200729A: further analysis of the NOT data
  58. GRB 200729A: Swift/UVOT Upper Limits
  59. GRB 200729A: Swift-XRT refined Analysis
  60. Fermi-GBM Sub-Threshold candidate for GRB 200729A
  61. GRB 200729A: Pan-STARRS pre-explosion source detection
  62. GRB 200729A: Spitzer archival source detection
  63. GRB 200729A: TNG NIR upper limits
  64. GRB 200729A: NOT optical upper limits
  65. Swift GRB 200729A: Global MASTER-Net observations report
  66. IceCube GCN Notice 134327_10548129 retraction
  67. GRB 200723A: ATLAS observations of GOTO candidate AT2020qer
  68. GRB 200723A: Swift ToO observations
  69. GRB 200723A: GOTO candidate afterglow and host galaxy
  70. Fermi GRB 200723A: Global MASTER-Net observations report
  71. GRB 200716C: Kitab optical observations
  72. GRB 200716C: CAHA optical observation // Anomalous light curve behavior?
  73. GRB 200716C: CrAO, Terskol, Assy-Turgen optical observations
  74. GRB 200714E: Swift-XRT afterglow detection
  75. GRB 200716C: FRAM-ORM afterglow detection
  76. Konus-Wind observation of GRB 200716C: correction to GCN 28147
  77. Konus-Wind observation of GRB 200716C
  78. GRB 200716C: VIRT optical detection.
  79. GRB 200716C: Insight-HXMT/HE detection
  80. AMON IC_HAWC 170720: Correction to ANTARES GCN 28142
  81. Fermi GRB 200718A: Global MASTER-Net observations report
  82. AMON IC_HAWC 170720: No Neutrino Counterpart detected with ANTARES
  83. GRB 200716C: CALET Gamma-Ray Burst Monitor detection
  84. GRB 200716C: Optical observations from HCT
  85. GRB 200716B: Insight-HXMT/HE detection
  86. GRB 200716C: Swift-BAT refined analysis
  87. GRB 200716C: Fermi GBM detection
  88. Fermi GRB 200716A: Global MASTER-Net observations report
  89. GRB 200716C: AGILE/MCAL detection
  90. GRB 200716C: possible host galaxy from the SDSS
  91. GRB 200716C: Swift-XRT refined analysis correction
  92. GRB 200716C: Fermi-LAT detection
  93. GRB 200716C: Swift-XRT refined Analysis
  94. GRB 200522A: HST NIR counterpart confirmation
  95. Swift GRB200716C: Global MASTER-Net OT detection
  96. IPN triangulation of GRB 200716A
  97. GRB 200716A: Fermi GBM detection
  98. Fermi GRB 200716B: Global MASTER-Net observations report
  99. GRB 200716B: AstroSat CZTI detection
  100. GRB 200716A: AstroSat CZTI detection

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