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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"

5863 results found.

  1. Fermi GRB 221211A: Global MASTER-Net observations report
  2. GRB 221209A: AstroSat CZTI detection
  3. GRB 221209A: BALROG localization (Fermi Trigger 692257829 / GRB 221209243)
  4. GRB 221202A: LCOGT Optical Upper Limits
  5. Optical polarization observation of GRB 221009A
  6. GRB 221120A: VIRT Optical Upper Limit
  7. Alert from the HAWC Burst Monitor HAWC-221123A
  8. GRB 221115B: CALET Gamma-Ray Burst Monitor detection
  9. GRB 221110A: COATLI Second-Epoch Upper Limits
  10. Correction to GCN 32852 (GRB 221009A: SARA-RM 1m Optical Afterglow Detection)
  11. GRB 221028A: AKO Optical Upper Limit
  12. GRB 221027A: AGILE detection
  13. GRB 221028B: MAXI/GSC detection
  14. GRB 221027A: Fermi GBM detection
  15. GRB 221027A: Fermi-LAT detection
  16. GRB 221027A: Fermi GBM Final Real-time Localization
  17. IPN triangulation of GRB 221022C (short)
  18. GRB 221021A: Fermi GBM observation
  19. GRB 221009A: Analysis of the initial episode using data of GBM/Fermi and SPI-ACS/INTEGRAL
  20. GRB 221021A: Swift/BAT-GUANO detection outside the coded FOV
  21. GRB 221021A: Fermi GBM Final Real-time Localization
  22. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  23. GRB 221009A: Second epoch of NuSTAR data
  24. GRB 220926B: Detection by GRBAlpha
  25. GRB 221009A: Gamma-ray Detection by SIRI-2
  26. GRB221009A: Detection as sudden ionospheric disturbances (SID)
  27. GRB 221009A: search for neutrinos with KM3NeT
  28. GRB 221009A: Lowell Discovery Telescope Afterglow Detection
  29. Fermi Gamma-ray Burst Monitor continues to detect SGR 1935+2154
  30. Fermi trigger No 687345829: Global MASTER-Net observations report
  31. Fermi trigger No 687344475: Global MASTER-Net observations report
  32. Fermi trigger No 687340841: Global MASTER-Net observations report
  33. Fermi trigger No 687337536: Global MASTER-Net observations report
  34. GRB 221009A: MITSuME Okayama optical observation
  35. Fermi trigger No 687281393: Global MASTER-Net observations report
  36. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  37. GRB 221009A: Detection by GRBAlpha
  38. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  39. GRB 221009A: BlackGEM optical observations
  40. GRB 221006A: CALET Gamma-Ray Burst Monitor detection
  41. GRB 221009A: Upper limits from a neutrino search with IceCube
  42. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  43. GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
  44. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  45. GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
  46. GRB 221009A/Swift J1913.1+1946: AMI-LA observations
  47. GRB 221009A: REM optical and NIR detection of the afterglow
  48. GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
  49. Swift J1913.1+1946: Early Optical Photometry
  50. GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
  51. GRB 221009A (Swift J1913.1+1946): Mondy optical observations
  52. Swift J1913.1+1946 : Pre-discovery limits from ZTF
  53. GRB 221009A: Fermi GBM observation
  54. Swift J1913.1+1946: Optical photometry
  55. Fermi trigger No 687014224: Global MASTER-Net observations report
  56. Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
  57. GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
  58. GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
  59. Swift GRB221009.59: Global MASTER-Net OT detection
  60. Swift J1913.1+1946 a new bright hard X-ray and optical transient
  61. GRB 220915A: Detection by GRBAlpha
  62. GRB 221006A: MAXI/GSC detection
  63. GRB 220930A: MITSuME Akeno optical upper limits
  64. GRB 220912A: Detection by VZLUSAT-2
  65. GRB220927A: Detection by GRBAlpha
  66. GRB 220930A: AbAO Optical Upper Limit
  67. Fermi trigger No 686403226: Global MASTER-Net observations report
  68. Fermi trigger No 686350260: Global MASTER-Net observations report
  69. GRB 220930A: AstroSat CZTI detection
  70. Swift GRB 220930A: Global MASTER-Net observations report
  71. GRB 220930A: COATLI Upper Limits
  72. GRB 220930A: Swift detection of a burst
  73. Fermi-LAT gamma-ray observations of IceCube-220928A
  74. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  75. IceCube-220928A - IceCube observation of a high-energy neutrino candidate track-like event
  76. Fermi GRB 220927A: Global MASTER-Net observations report
  77. Integral GRB220926.44: Global MASTER-Net observations report
  78. Swift GRB220926.34: Global MASTER-Net observations report
  79. Swift GRB 220926A: Global MASTER-Net observations report
  80. GRB 220926A: Swift detection of a burst
  81. Fermi GRB 220925A: Global MASTER-Net observations report
  82. GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
  83. GRB 220921A: further MeerLICHT observations
  84. Fermi trigger No 685748699: Global MASTER-Net observations report
  85. Swift GRB220923.47: Global MASTER-Net observations report
  86. GRB 220921A: DDOTI Detection of the Afterglow
  87. GRB 220921A: MASTER OT inside Fermi-LAT error-box
  88. LAT GRB220921.46: Global MASTER-Net observations report
  89. Fermi trigger No 685452089: Global MASTER-Net observations report
  90. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  91. IceCube-220918A: Upper limits from a search for additional neutrino events in IceCube
  92. IceCube Alert 220918.53: Global MASTER-Net observations report
  93. IceCube-220918A - IceCube observation of a high-energy neutrino candidate track-like event
  94. Fermi trigger No 684894705: Global MASTER-Net observations report
  95. IceCube-220907A: No significant detection in HAWC
  96. Fermi trigger No 684927323: Global MASTER-Net observations report
  97. Fermi trigger No 684911625: Global MASTER-Net observations report
  98. Fermi trigger No 684716840: Global MASTER-Net observations report
  99. Fermi GRB 220912A: Global MASTER-Net observations report
  100. GRB 220912A: AstroSat CZTI detection

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