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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

32766 results found.

  1. GRB 211221A: NOT optical limits
  2. Swift GRB 211221A: Global MASTER-Net observations report
  3. IceCube-211216B: No significant detection in HAWC
  4. IceCube-211216A: No significant detection in HAWC
  5. GRB 211219A: AGILE detection
  6. GRB 211219A: Swift/BAT-GUANO detection outside the coded FOV
  7. Fermi GRB 211219B: Global MASTER-Net observations report
  8. Fermi GRB 211219A: Global MASTER-Net observations report
  9. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
  10. GRB 211216A: Fermi GBM observation
  11. IceCube-211216B: No neutrino counterpart candidates in ANTARES search
  12. GRB 211106A: XMM-Newton monitoring campaign detections
  13. Fermi-LAT Gamma-ray Observations of IceCube-211216B
  14. Fermi-LAT Gamma-ray Observations of IceCube-211216A
  15. IceCube-211216B: Upper limits from Fermi-GBM Observations
  16. IceCube-211216A: Upper limits from Fermi-GBM Observations
  17. IceCube-211216A: No neutrino counterpart candidates in ANTARES search
  18. GRB 211216A: Swift/BAT-GUANO detection outside the coded FOV
  19. Fermi GRB 211216B: Global MASTER-Net observations report
  20. GRB 211216B: GECAM detection
  21. IceCube-211216A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  22. GRB 211211A: TNG NIR observations
  23. GRB 211216A: GECAM detection
  24. Fermi GRB 211216A: Global MASTER-Net observations report
  25. GRB 211211A: Insight-HXMT/HE detection
  26. GRB 211211A - Gemini K-band detection
  27. GRB 211211A: SAO RAS optical observations
  28. GRB 211211A: AbAO optical observations
  29. GRB 211211A: GMG upper limit
  30. Chandra observation of GW170817 at ~1575 days since merger (all epochs)
  31. GRB 211211A: redshift estimation and SPI-ACS/INTEGRAL detection
  32. GRB 211211A: Very fast decay observed from CAFOS/2.2mCAHA
  33. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  34. GRB 211211A: HCT and GIT optical follow up observations
  35. GRB 211211A: CALET Gamma-Ray Burst Monitor detection
  36. IceCube-211208A: No neutrino counterpart detected with ANTARES
  37. Fermi GRB 211212A: Global MASTER-Net observations report
  38. GRB 211211A: incorrect E_iso value in GCN 31221
  39. GRB 211211A: Swift/UVOT detection
  40. GRB 211211A: NOT optical spectroscopy
  41. GRB 211211B: GECAM detection
  42. Fermi GRB 211212B: Global MASTER-Net observations report
  43. GRB 211211A: Afterglow detection from CAFOS/2.2m CAHA
  44. GRB 211211A: MITSuME Akeno optical observation
  45. Swift GRB 211211A: Global MASTER-Net observations report
  46. GRB 211211A: LCO Optical Observations
  47. GRB 211211A: Nanshan/NEXT optical observations
  48. GRB 211211A: Swift-XRT refined Analysis
  49. GRB 211211A: Fermi GBM observation
  50. GRB 211211A: Swift-BAT refined analysis
  51. Fermi GRB 211211B: Global MASTER-Net observations report
  52. Fermi GRB 211211A: Global MASTER-Net observations report
  53. GRB 211207A: Swift/UVOT Detection
  54. IceCube-211208A: No significant detection in HAWC
  55. AMON NuEm-211020A: No neutrino counterpart detected with ANTARES
  56. GRB 211130A: MeerLICHT identification of possible afterglow candidate
  57. Fermi-LAT Gamma-ray Observations of IceCube-211208A
  58. IceCube-211208A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  59. GRB 211207A: Swift-BAT refined analysis
  60. GRB 211207A: VLT/X-shooter redshift
  61. GRB 211204C: Fermi GBM detection
  62. GRB 211207A: Swift-XRT refined Analysis
  63. Swift GRB 211207A: Global MASTER-Net observations report
  64. GRB 211206A: AstroSat CZTI detection
  65. GRB 211204C: AstroSat CZTI detection
  66. IPN triangulation of GRB 211204C
  67. GRB 211206A: Swift/BAT-GUANO detection outside the coded FOV
  68. GRB 211204C: Swift/BAT-GUANO detection outside the coded FOV
  69. GRB 211204C: GECAM detection
  70. Fermi GRB 211204C: Global MASTER-Net observations report
  71. Fermi GRB 211204B: Global MASTER-Net observations report
  72. Fermi GRB 211204A: Global MASTER-Net observations report
  73. GRB 211124A: Fermi GBM Observation
  74. Swift Trigger 1086826 (possible GRB 211203A) is likely not an astrophysical event
  75. Swift GRB 211203A: Global MASTER-Net observations report
  76. Fermi GBM Upper limits for GRB 211203A
  77. Konus-Wind detection of GRB 211130A
  78. IPN triangulation of GRB 211130A
  79. GRB 211201A: GECAM detection
  80. GRB 211201A: Swift/BAT-GUANO detection likely outside the coded FOV
  81. Fermi GRB 211201A: Global MASTER-Net observations report
  82. Fermi GRB 211130A: Global MASTER-Net observations report
  83. IceCube-211125A: No significant detection in HAWC
  84. GRB 211106A: GECAM detection
  85. GRB 211129A: Swift-BAT refined analysis
  86. GRB 211129A: Swift-XRT refined Analysis
  87. GRB 211129A: Swift/UVOT Upper Limits
  88. GRB 211129A: Fermi GBM observation
  89. Swift GRB 211129A: Global MASTER-Net observations report
  90. GRB 211129A: Nanshan/NEXT optical upper limit
  91. IPN triangulation of GRB 211118A
  92. GRB 211129A: MITSuME Akeno optical upper limits
  93. IceCube-211125A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  94. GRB 211023A: Xinglong 2.16m optical observations
  95. Fermi-LAT Gamma-ray Observations of IceCube-211125A
  96. GRB 211120548: Fermi GBM observation
  97. Konus-Wind detection of GRB 211120A
  98. IPN triangulation of GRB 211120A
  99. IceCube-211125A: No neutrino counterpart detected with ANTARES
  100. Chandra observations of GRB 210905A

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