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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"

33633 results found.

  1. Fermi GRB 211211B: Global MASTER-Net observations report
  2. GRB 211211B: Fermi GBM Final Real-time Localization
  3. Fermi GRB 211211A: Global MASTER-Net observations report
  4. GRB 211211A: Enhanced Swift-XRT position
  5. GRB 211207A: Swift/UVOT Detection
  6. GRB 211211A: KAIT Optical Afterglow Candidate
  7. GRB 211211A: Swift detection of a bright burst
  8. GRB 211211A: Fermi GBM Final Real-time Localization
  9. GRB 211130A: MeerLICHT identification of possible afterglow candidate
  10. IceCube-211208A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  11. GRB 211207A: Swift-BAT refined analysis
  12. GRB 211207A: VLT/X-shooter redshift
  13. GRB 211204C: Fermi GBM detection
  14. GRB 211207A: Swift-XRT refined Analysis
  15. GRB 211207A: Enhanced Swift-XRT position
  16. Swift GRB 211207A: Global MASTER-Net observations report
  17. GRB 211207A: Swift detection of a burst with an optical counterpart
  18. GRB 211206A: Not observable by Fermi-GBM
  19. GRB 211206A: AstroSat CZTI detection
  20. GRB 211206B: AstroSat CZTI detection
  21. GRB 211204C: AstroSat CZTI detection
  22. IPN triangulation of GRB 211204C
  23. GRB 211206A: Swift/BAT-GUANO detection outside the coded FOV
  24. GRB 211206A: AGILE/MCAL detection of a burst
  25. GRB 211204C: Swift/BAT-GUANO detection outside the coded FOV
  26. GRB 211204C: GECAM detection
  27. Fermi GRB 211204C: Global MASTER-Net observations report
  28. GRB 211204C: Fermi GBM Final Real-time Localization
  29. Fermi GRB 211204B: Global MASTER-Net observations report
  30. GRB 211204B: Fermi GBM Final Real-time Localization
  31. Fermi GRB 211204A: Global MASTER-Net observations report
  32. GRB 211204A: Fermi GBM Final Real-time Localization
  33. GRB 211124A: Fermi GBM Observation
  34. Swift Trigger 1086826 (possible GRB 211203A) is likely not an astrophysical event
  35. Swift GRB 211203A: Global MASTER-Net observations report
  36. Fermi GBM Upper limits for GRB 211203A
  37. Konus-Wind detection of GRB 211130A
  38. IPN triangulation of GRB 211130A
  39. GRB 211203A: Swift detection of a burst
  40. GRB 211201A: GECAM detection
  41. GRB 211201A: Swift/BAT-GUANO detection likely outside the coded FOV
  42. GRB 211106A: Second HST Observation
  43. Fermi GRB 211201A: Global MASTER-Net observations report
  44. GRB 211201A: Fermi GBM Final Real-time Localization
  45. Fermi GRB 211130A: Global MASTER-Net observations report
  46. GRB 211130A: BALROG localization (Fermi Trigger 659978192 / GRB 211130636)
  47. GRB 211130A: Fermi GBM Final Real-time Localization
  48. GRB 211106A: GECAM detection
  49. GRB 211129A: Swift-BAT refined analysis
  50. GRB 211129A: Swift-XRT refined Analysis
  51. GRB 211129A: Swift/UVOT Upper Limits
  52. GRB 211106A: HST Observations
  53. GRB 211106A: Chandra Observations
  54. GRB 211129A: Fermi GBM observation
  55. Swift GRB 211129A: Global MASTER-Net observations report
  56. GRB 211129A: Nanshan/NEXT optical upper limit
  57. GRB 211129A: Enhanced Swift-XRT position
  58. IPN triangulation of GRB 211118A
  59. GRB 211129A: MITSuME Akeno optical upper limits
  60. GRB 211129A: Swift detection of a burst
  61. IceCube-211125A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  62. GRB 211023A: Xinglong 2.16m optical observations
  63. GRB 211023A: Xinglong 2.16m optical observations
  64. GRB 211120548: Fermi GBM observation
  65. Konus-Wind detection of GRB 211120A
  66. IPN triangulation of GRB 211120A
  67. Chandra observations of GRB 210905A
  68. GRB 211118A: Fermi GBM detection
  69. IceCube-211123A: Upper limits from Fermi-GBM Observations
  70. IPN triangulation of GRB 211124A (short)
  71. HAWC-211123A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  72. GRB 211124A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  73. GRB 211023B: LBT likely spectroscopic redshift of the host galaxy
  74. GRB 211120A: AGILE detection
  75. GRB 211120A: AstroSat CZTI detection
  76. GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV
  77. GRB 211120A: GECAM detection
  78. GRB 211118A: AstroSat CZTI detection
  79. GRB 211023A: optical observations and photometric evidence of supernova
  80. GRB211118A: Swift/BAT-GUANO detection outside the coded FOV
  81. Konus-Wind detection of GRB 211107B
  82. GRB 211115A: CALET Gamma-Ray Burst Monitor detection
  83. GRB 211115A: MAXI/GSC detection
  84. GRB 211023A: classification and SPI-ACS/INTEGRAL registration
  85. Fermi GRB 211112A: Global MASTER-Net observations report
  86. GRB 211106A: Swift/UVOT upper limits
  87. IPN triangulation of GRB 211106A (short)
  88. GRB 211112A: Fermi GBM Final Real-time Localization
  89. GRB 211110A: AstroSat CZTI detection
  90. Short GRB 211106A: spectroscopy of galaxies in the field
  91. GRB 211110A: GECAM detection
  92. GRB 211107B: Swift-XRT afterglow detection
  93. GRB 211107A: GECAM detection
  94. GRB 211106A: VLT/FORS2 optical observations
  95. GRB 211106A, GROND observations
  96. GRB 211106A: Swift-XRT afterglow detection
  97. Fermi GRB 211109B: Global MASTER-Net observations report
  98. GRB 211023A: SAO RAS optical observations
  99. GRB 211107B: Swift-XRT observations
  100. MeerLICHT follow-up of GRB 211106A

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