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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"

28715 results found.

  1. GRB 220117C: Fermi GBM Observation
  2. GRB 220118A: 2.2m CAHA/CAFOS detections
  3. GRB 220118A: Fermi GBM detection
  4. GRB 220118A: COATLI Optical Observations
  5. GRB 220101A: KAO optical-R observation
  6. GRB 211221A: No V & R detection, KAO telescope
  7. GRB 220118A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  8. GRB 220117C: Swift/BAT-GUANO arcminute localization
  9. Swift currently in safe hold with science slews disabled
  10. GRB 220118A: Swift-BAT refined analysis
  11. GRB 220118A: Swift/UVOT Detection
  12. Konus-Wind observation of the recent SGR 1935+2154 activity
  13. GRB 220118A: GIT optical observations
  14. GRB 220118A: MITSuME Akeno optical observation
  15. GRB 220117B: z-band limit
  16. Swift GRB 220118A: Global MASTER-Net observations report
  17. GRB 220117A: MITSuME Akeno optical upper limits
  18. Fermi GBM Sub-Threshold Detection of GRB 220117A
  19. GRB 220117B: Swift-BAT refined analysis
  20. GRB 220117A: Swift-BAT refined analysis
  21. GRB 220117B: Swift/UVOT Upper Limits
  22. GRB 220117A: Swift/UVOT Upper Limits
  23. GRB 220117A: LCO Optical Observations
  24. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  25. Fermi-LAT Gamma-ray Observations of IceCube-220115A and detection of a new gamma-ray source, Fermi J2350.2+2620
  26. GRB 220117B: Swift-XRT refined Analysis
  27. GRB 220117A: Swift-XRT refined Analysis
  28. GRB 220117B: Nanshan/NEXT optical upper limit
  29. GRB 220117B: MITSuME Akeno optical upper limits
  30. GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
  31. Swift GRB 220117A: Global MASTER-Net observations report
  32. Swift GRB 220117B: Global MASTER-Net observations report
  33. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  34. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  35. GRB 210919A: LBT spectroscopic redshift of the host galaxy candidates
  36. AGILE observations of a burst from SGR 1935+2154
  37. GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
  38. GRB 220111A: AstroSat CZTI detection
  39. Fermi GRB 220111A: Global MASTER-Net observations report
  40. Konus-Wind detection of GRB 220101A (correction to GCN 31433)
  41. Konus-Wind detection of GRB 220101A
  42. GRB 220107A: SAO RAS optical observations
  43. Konus-Wind detection of GRB 220107B
  44. Konus-Wind detection of GRB 220107A
  45. Confirmation of the X-ray afterglow of GRB 220107B
  46. GRB 220107A: further SAO RAS optical observations
  47. GRB 220101A: Additional Liverpool telescope photometry
  48. GRB 220107A: SAO RAS optical observations
  49. GRB 220101A: SAO RAS optical observations
  50. GRB 220107A: AbAO and Terskol optical observations
  51. GRB 220107B: MITSuME Akeno optical upper limits
  52. GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
  53. GRB 220107A: Nanshan/NEXT optical observations
  54. GRB 220107A: Swift/UVOT Detection
  55. GRB 220107B: Fermi GBM observations
  56. GRB 220107A: MITSuME Akeno optical observation
  57. GRB 220107B: AstroSat CZTI detection
  58. GRB 220107B: Swift-XRT afterglow detection
  59. GRB 220107A: Swift-XRT afterglow detection
  60. GRB 220107A: AstroSat CZTI detection
  61. GRB 220107B: Tiled Swift observations
  62. GRB 220107A: Fermi GBM observations
  63. GRB 220107A: Swift ToO observations
  64. Fermi GRB 220107A: Global MASTER-Net observations report
  65. GRB 220107A: Swift/BAT-GUANO arcminute localization
  66. GRB 220101A: Tautenburg observations
  67. GRB 220101A: Continued Mondy optical observations
  68. GRB 220101A: further TNG NIR observations
  69. GRB 220101A: continued 1.3m DFOT Optical Observations
  70. GRB 220104A: Fermi GBM Observation
  71. GRB 220101A: Mondy optical observations
  72. GRB 220101A: 3rd LCO Optical Observation
  73. GRB 220101A: iTelescope optical observations
  74. GRB 211227A: Lijiang 2.4m Telescope Optical Observations
  75. GRB 220101A: VLA detection
  76. GRB 220101A: 1.3m DFOT observations
  77. GRB 220101A: LCO Continued Optical Observations
  78. GRB 220104A:GECAM detection
  79. Fermi GRB 220104A: Global MASTER-Net observations report
  80. GRB 211229B: Fermi GBM observation
  81. Fermi GRB 220103A: Global MASTER-Net observations report
  82. GRB 211227A: Gemini South Optical Observations
  83. GRB 211229B: Swift/BAT-GUANO detection outside the coded FOV
  84. GRB 220101A: TNG NIR afterglow detection
  85. GRB 220101A: ALMA detection
  86. GRB 220101A: LCO Optical Observations
  87. GRB 220101A: Tautenburg observations
  88. GRB 220101A: Swift-BAT refined analysis
  89. GRB 220101A: GMG observation (2nd epoch)
  90. GRB 211231A: AstroSat CZTI detection
  91. GRB 220101A: OASDG optical observations
  92. GRB 220101A : Eiso equals the maximum isotropic GRB energy
  93. GRB 220101A: GMG observation
  94. GRB 220101A: Asiago spectroscopic and photometric detection
  95. GRB220101A: optical afterglow detection from Konkoly Observatory
  96. GRB 220101A: Fermi GBM Detection
  97. GRB 220101A: NOT redshift confirmation
  98. GRB 220101A: CAHA 2.2m/CAFOS detection
  99. GRB 220101A: Liverpool telescope imaging of a high-redshift afterglow
  100. GRB 220101A: Swift-XRT refined Analysis

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