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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"

28724 results found.

  1. Fermi GRB 200824A: Global MASTER-Net observations report
  2. GRB200826A: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi Short GRB (Trigger 620108997)
  3. Konus-Wind detection of GRB 200826A
  4. GRB200826A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 620108997)
  5. IPN triangulation of GRB 200826A (short/bright)
  6. GRB 200826A: Tiled Swift observations
  7. GRB 200826A: AGILE detection
  8. GRB 200826A: AstroSat CZTI detection
  9. GRB 200826A: Fermi GBM observation
  10. Fermi GRB 200826A: Global MASTER-Net observations report
  11. Swift Trigger 992444 is due to detector noise
  12. GRB 200819A: Swift/UVOT Upper Limits
  13. IceCube-200806A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  14. Konus-Wind observation of GRB 200815A
  15. GRB 200819A: Swift-BAT refined analysis
  16. GRB 200815A: MASTER optical observations
  17. IPN triangulation of GRB 200815A (short)
  18. GRB 200819A: Optical Observations from HCT
  19. GRB 200819A: Swift-XRT refined Analysis
  20. GRB 200819A: MITSuME Ishigaki optical upper limits
  21. GRB 200729A: Lowell Discovery Telescope observations
  22. GRB 200819A: MITSuME Akeno optical upper limits
  23. GRB 200819A: Kitab, TSHAO optical upper limit
  24. Swift GRB 200819A: Global MASTER-Net observations report
  25. Swift Trigger 990358 is due to detector noise
  26. Swift Trigger 989458 is due to detector noise
  27. Fermi GRB 200817A: Global MASTER-Net observations report
  28. GRB 200815A: CALET Gamma-Ray Burst Monitor detection of a short burst
  29. Alert from the HAWC Burst Monitor HAWC-200814A
  30. IceCube200806A: No significant detection in HAWC
  31. GRB 200809B: Fermi GBM detection
  32. Fermi GRB 200809B: Global MASTER-Net observations report
  33. GRB 200809B: Swift-XRT afterglow detection
  34. GRB 200809B: MAXI/GSC detection
  35. GRB 200809B: Swift ToO observations
  36. GRB 200809B: AstroSat CZTI detection
  37. GRB 200809B: Swift/BAT-GUANO detection and arcminute localization
  38. GRB 200808A: AGILE detection
  39. GRB 200806A: CALET Gamma-Ray Burst Monitor detection
  40. Fermi GRB 200808A: Global MASTER-Net observations report
  41. GRB 200806A: Nanshan/NEXT optical upper limit
  42. IPN triangulation of GRB 200805A (short)
  43. GRB 200806A: CAHA optical afterglow confirmation
  44. GRB 200803A: Chilescope optical upper limit
  45. GRB 200806A: VIRT optical observations
  46. GRB 200806A: Swift-BAT refined analysis
  47. GRB 200806A: Swift/UVOT Possible Detection
  48. GRB 200806A: Swift-XRT refined Analysis
  49. Fermi-LAT Gamma-ray Observations of IceCube-200806A
  50. CGBM-SPI-ACS triangulation of short GRB 200805A
  51. GRB 200806A: AbAO optical upper limit
  52. GRB 200805A: CALET Gamma-Ray Burst Monitor detection of a short burst
  53. GRB 200806A: AstroSat CZTI detection
  54. GRB 200806A: MITSuME Akeno optical upper limits
  55. IceCube-200806A: Upper limits from Fermi-GBM Observations
  56. Swift GRB 200806A: Global MASTER-Net observations report
  57. GRB 200803B: MASTER possibly OT discovery
  58. GRB 200803A: AstroSat CZTI detection
  59. GRB 200803A: Fermi GBM detection
  60. GRB 200803A: Swift-XRT afterglow detection
  61. Fermi GRB 200803B: Global MASTER-Net observations report
  62. GRB 200803A: Fermi-LAT detection
  63. GRB 200803A: MASTER optical counterpart discovery
  64. GRB 200803A: Tiled Swift observations
  65. Fermi GRB 200803A: Global MASTER-Net observations report
  66. GRB 200801B: AstroSat CZTI detection
  67. Fermi GRB 200801B: Global MASTER-Net observations report
  68. Fermi GRB 200802A: Global MASTER-Net observations report
  69. AX J1846.4-0258: Swift-BAT refined analysis
  70. Konus-Wind detection of GRB 200729A
  71. Fermi GRB 200801A: Global MASTER-Net observations report
  72. GRB 200729A: RT-22 observations at 36.8 GHz
  73. GRB 200729A: VLA Observations
  74. GRB 200729A: Nanshan/NEXT optical upper limit
  75. GRB 200729A: Swift-BAT refined analysis
  76. GRB 200729A: further analysis of the NOT data
  77. GRB 200729A: Swift/UVOT Upper Limits
  78. GRB 200729A: Swift-XRT refined Analysis
  79. Fermi-GBM Sub-Threshold candidate for GRB 200729A
  80. GRB 200729A: Pan-STARRS pre-explosion source detection
  81. GRB 200729A: Spitzer archival source detection
  82. GRB 200729A: TNG NIR upper limits
  83. GRB 200729A: NOT optical upper limits
  84. Swift GRB 200729A: Global MASTER-Net observations report
  85. IceCube GCN Notice 134327_10548129 retraction
  86. GRB 200723A: ATLAS observations of GOTO candidate AT2020qer
  87. GRB 200723A: Swift ToO observations
  88. GRB 200723A: GOTO candidate afterglow and host galaxy
  89. Fermi GRB 200723A: Global MASTER-Net observations report
  90. GRB 200716C: Kitab optical observations
  91. GRB 200716C: CAHA optical observation // Anomalous light curve behavior?
  92. GRB 200716C: CrAO, Terskol, Assy-Turgen optical observations
  93. GRB 200714E: Swift-XRT afterglow detection
  94. GRB 200716C: FRAM-ORM afterglow detection
  95. Konus-Wind observation of GRB 200716C: correction to GCN 28147
  96. Konus-Wind observation of GRB 200716C
  97. GRB 200716C: VIRT optical detection.
  98. GRB 200716C: Insight-HXMT/HE detection
  99. AMON IC_HAWC 170720: Correction to ANTARES GCN 28142
  100. Fermi GRB 200718A: Global MASTER-Net observations report

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