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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"

39489 results found.

  1. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  2. IceCube Alert 210510.20: Global MASTER-Net observations report
  3. GRB 210510A: Fermi GBM Final Real-time Localization
  4. GRB 210509A: RATIR Optical and NIR Upper Limits
  5. GRB 210509A: Swift/UVOT Upper Limits
  6. GRB 210509A: Swift-XRT refined Analysis
  7. GRB 210509A: Swift-BAT refined analysis
  8. Swift GRB 210509A: Global MASTER-Net observations report
  9. GRB 210509A: Enhanced Swift-XRT position
  10. GRB 210509A: BOOTES-4/MET optical upper limit
  11. GRB 210509A: Swift-XRT observations
  12. GRB 210509A: Swift detection of a burst
  13. GRB 210506A: Swift/BAT-GUANO position retraction
  14. IPN triangulation of GRB 210506A
  15. Fermi GRB 210507A: Global MASTER-Net observations report
  16. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  17. ZTF21aayokph (AT2021lfa): continued Mondy optical observations
  18. GRB 210507A: Fermi GBM Final Real-time Localization
  19. Integral GRB210507.04: Global MASTER-Net observations report
  20. Integral GRB210506.78: Global MASTER-Net observations report
  21. GRB 210506A: Swift-XRT observations
  22. HAWC GRB 210507.443: DDOTI Upper Limit
  23. GRB 210506A: Nanshan/NEXT optical upper limit
  24. GRB 210506A: TNG NIR upper limits
  25. ZTF21aayokph (AT2021lfa): Mondy and Koshka observatory optical observations
  26. ZTF21aayokph (AT2021lfa): X-ray Detection with Swift/XRT
  27. ZTF21aayokph (AT2021lfa): Assy optical observations
  28. GRB 210506A: Swift ToO observations
  29. ZTF21aayokph (AT2021lfa): Nanshan/NEXT optical upper limit
  30. GRB 210506A: Swift/BAT-GUANO detection and possible arcminute localization of a short hard burst
  31. GRB 210504A: Lowell Discovery Telescope optical observations
  32. ZTF21aayokph (AT2021lfa): Redshift from Gemini South
  33. GRB 210504A: VLT X-shooter redshift
  34. GRB 210424B: AstroSat CZTI detection
  35. GRB 210504A: Swift-XRT refined Analysis
  36. GRB 210504A: Swift-BAT refined analysis
  37. GRB 210504A: NOT optical afterglow detection
  38. GRB 210504A: MITSuME Akeno optical upper limits
  39. Fermi GRB 210503A: DDOTI Upper Limits on the Afterglow
  40. GRB 210504A: AST3-3 YaoAn Optical Upper Limit
  41. GRB 210504A: Swift/UVOT Detection
  42. GRB 210504A: BOOTES-4/MET optical upper limit
  43. Swift GRB210504.58: Global MASTER-Net observations report
  44. GRB 210504A: update on the BAT trigger time and burst duration
  45. GRB 210504A: Swift detection of a burst
  46. Fermi GRB 210503A: Global MASTER-Net observations report
  47. GRB 210503A: Fermi GBM Final Real-time Localization
  48. Swift GRB210502.74: Global MASTER-Net observations report
  49. Swift Detection of MAXI J1803-298 including an optical counterpart
  50. MAXI GRB210501.83: Global MASTER-Net observations report
  51. Fermi GRB 210501A: Global MASTER-Net observations report
  52. Fermi trigger No 641601187: Global MASTER-Net observations report
  53. GRB 210430A: BOOTES-1 optical limit
  54. GRB 210424B: MITSuME Akeno optical upper limits
  55. GRB 210501A: Fermi GBM Final Real-time Localization
  56. GRB 210430A: Swift-BAT refined analysis
  57. Fermi GRB 210430B: Global MASTER-Net observations report
  58. GRB 210430B: Fermi GBM Final Real-time Localization
  59. Swift GRB210430.45: Global MASTER-Net observations report
  60. GRB 210430A: Swift detection of a burst
  61. GRB 210424B: CALET Gamma-Ray Burst Monitor detection
  62. GRB 210413B: Swift/UVOT Observations
  63. Konus-Wind detection of GRB 210424B
  64. Delayed GRB GCN Notices from Swift
  65. IPN triangulation of GRB 210424B (short/hard)
  66. GRB 210323B: Swift-XRT observations
  67. Swift Trigger 1045571 is not a GRB
  68. GRB 210427A: GECAM detection
  69. GRB 210427A: BALROG localization (Fermi Trigger / GRB 210427206)
  70. Fermi GRB 210427A: Global MASTER-Net observations report
  71. GRB 210427A: Fermi GBM Final Real-time Localization
  72. GRB 210422B: Fermi GBM Final Localization
  73. GRB 210420B: Assy optical observations
  74. Fermi trigger No 640975205: Global MASTER-Net observations report
  75. GRB 210425A: GECAM detection
  76. GRB 210424.694: DDOTI Upper Limits on the Afterglow
  77. GRB 210422A: Swift-BAT refined analysis
  78. GRB 210424A: Fermi GBM Final Real-time Localization
  79. GRB 210420B: follow-up photometry of optical afterglow at INASAN/Simeiz
  80. GRB 210420B: Zeiss-1000 of Koshka optical observations
  81. GRB 210421A: Swift-BAT refined analysis
  82. GRB 210421B: Swift-XRT observations
  83. GRB 210421B: AstroSat CZTI detection
  84. GRB 210420B: continued Tautenburg observations
  85. GRB 210421A: GECAM detection
  86. GRB 210421B: AstroSat CZTI detection
  87. Swift GRB210422.74: Global MASTER-Net observations report
  88. GRB 210422A: Swift detection of a burst
  89. GRB 210421A: Swift/UVOT Upper Limits
  90. GRB 210420B: Correction to AST3-3 YaoAn magnitude
  91. GRB 210420B: follow-up photometry of the optical afterglow at Konkoly
  92. GRB 210421A: MITSuME Akeno optical upper limits
  93. GRB 210419B: AstroSat CZTI detection
  94. Fermi Gamma-ray Burst Monitor trigger 210421C is not a GRB
  95. GRB 210420B: Swift-BAT refined analysis
  96. GRB 210421B: Swift ToO observations
  97. GRB 210421B: Swift/BAT-GUANO detection and arcminute localization
  98. GRB 210420B: Swift-XRT refined Analysis
  99. GRB 210421A: Swift-XRT refined Analysis
  100. GRB 210421B: Correction of GRB Type to "Likely Long GRB"

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