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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"

19662 results found.

  1. GRB 200306A: AstroSat CZTI detection
  2. GRB 200306C: LCO Optical Upper Limits
  3. GRB 200306C: Liverpool Telescope observations
  4. GRB 200306C: SAO RAS observations of OT
  5. GRB 200306C: GOTO upper limits
  6. GRB 200306A: Swift-XRT refined Analysis
  7. GRB 200306C: BOOTES-1 detection of the optical afterglow
  8. Swift GRB200306.95: Global MASTER-Net observations report
  9. GRB 200306C: Swift detection of a burst with an optical counterpart
  10. Swift GRB200306.95: Global MASTER-Net OT detection
  11. Swift GRB200306.95: Global MASTER-Net OT detection
  12. GRB 200306A: Potential LCO Optical Afterglow Detection
  13. GRB 200306A: Swift detection of a burst
  14. Swift GRB200306.01: Global MASTER-Net observations report
  15. Konus-Wind observation of GRB200303A
  16. GRB 200303A: Fermi GBM observation
  17. GRB 200303A: Swift-XRT refined Analysis
  18. GRB 200303A: Swift-BAT refined analysis
  19. GRB 200303A: NOT optical observations
  20. GRB 200303A: Swift/UVOT Upper Limits
  21. GRB 200303A: FRAM-ORM optical limit
  22. GRB 200219A: AstroSat CZTI detection
  23. GRB 200303A: GOTO observations upper limit
  24. GRB 200228A: AstroSat CZTI detection
  25. GRB 200303A: CALET Gamma-Ray Burst Monitor detection
  26. GRB 200303A: Enhanced Swift-XRT position
  27. GRB 200303A: Swift detection of a burst
  28. Swift GRB200303.11: Global MASTER-Net observations report
  29. LIGO/Virgo S200302c: no counterpart candidates in the Swift/BAT observations
  30. LIGO/Virgo S200224ca: Transient found in Swift/UVOT counterpart search
  31. GRB 200228B: LCO Optical Upper Limit
  32. GRB 200228B: Swift-BAT refined analysis
  33. GRB 200228B: RATIR Optical Observations
  34. GRB 200228B: Swift-XRT refined Analysis
  35. Swift GRB 200228B: Global MASTER-Net observations report
  36. GRB 200228B: Swift/UVOT Upper Limits
  37. GRB 200228B: RATIR Optical Observations
  38. GRB 200228B: Fermi GBM observation
  39. GRB 200227A: RATIR Optical Observations
  40. GRB 200228B: KAIT Optical Upper Limit
  41. GRB 200228A: Fermi GBM observation
  42. GRB 200228A: Swift/BAT detection and arcminute localization from GUANO
  43. GRB 200227A: Mondy optical upper limit
  44. GRB 200228B: Enhanced Swift-XRT position
  45. GRB 200228B: Swift detection of a burst
  46. GRB 200227A: Insight-HXMT/HE detection
  47. GRB 200227A: Swift-XRT refined Analysis
  48. GRB 200227A: Swift-BAT refined analysis
  49. GRB 200227A: Swift/UVOT Upper Limits
  50. GRB 200227A: Enhanced Swift-XRT position
  51. HAWC-200216A: No Neutrino Counterpart in ANTARES Search
  52. GRB 200227A: Fermi GBM observation
  53. GRB 200227A: MITSuME Akeno optical upper limit
  54. GRB 200227A: Swift detection of a burst
  55. Konus-Wind observation of GRB 200219A
  56. GRB 200224A: Calar Alto 2.2m optical afterglow detection
  57. LIGO/Virgo S200225q: no counterpart candidates in the Swift/BAT observations
  58. LIGO/Virgo S200224ca: no counterpart candidates in the Swift/BAT observations
  59. GRB 200224A: Swift-BAT refined analysis
  60. GRB 200224A: LCO Upper Limits
  61. GRB 200224A: RATIR Optical Observations and Confirmation of the Afterglow
  62. GRB 200224A: Swift/UVOT Detection
  63. GRB 200219C: Swift-XRT afterglow confirmation
  64. GRB 200224A: Swift-XRT refined Analysis
  65. GRB 200224A: BOOTES-1 and 1.5m OSN optical observations
  66. GRB 200224A: Swift detection of a burst
  67. Swift GRB200224.14: Global MASTER-Net observations report
  68. GRB 200219A: UVOT Upper Limits
  69. GRB 200219A: FRAM-Auger optical limit
  70. GRB 200219C: Nanshan/NEXT optical upper limit and possible host galaxy from PanSTARRS
  71. GRB 200219C: Swift-XRT afterglow detection
  72. LIGO/Virgo S200213t: Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  73. GRB 200219C: Tiled Swift observations
  74. GRB 200219C: Fermi-LAT detection
  75. GRB 200215A: LCO Optical Upper Limits
  76. GRB 200219A, Swift-BAT refined analysis
  77. LIGO/Virgo S200219ac: no counterpart candidates in the Swift/BAT observations
  78. GRB 200219A: Swift-XRT refined Analysis correction
  79. GRB 200219A: Swift-XRT refined Analysis
  80. GRB 200219A: Enhanced Swift-XRT position
  81. GRB 200219A: Fermi GBM observation
  82. GRB 200216B: second epoch optical upper limit at Mondy observatory
  83. GRB 200219A: Swift detection of a short burst
  84. Swift GRB200219.32: Global MASTER-Net observations report
  85. GRB 200216B: Mondy and AbAO optical upper limits
  86. LIGO/Virgo (S200213t/IceCube neutrino candidate: No counterpart candidates in the Swift-XRT Observations
  87. GRB 200216B: Swift-XRT refined Analysis
  88. GRB 200216B: Swift-BAT refined analysis
  89. Further Swift-XRT observations of Swift J0840.7-3516
  90. GRB 200215A: CALET Gamma-Ray Burst Monitor detection
  91. GRB 200216A: Fermi GBM detection
  92. GRB 200216B: Fermi GBM observation
  93. GRB 200216B: Swift/UVOT Upper Limits
  94. GRB 200216A: Swift/BAT detection and arcminute localization from GUANO
  95. GRB 200216B: Enhanced Swift-XRT position
  96. GRB 200215A: RATIR Optical Observations
  97. GRB 200216B: GMG upper limit
  98. GRB 200216B: Swift detection of a burst
  99. Swift GRB200216.56: Global MASTER-Net observations report
  100. GRB 200215A: Swift-BAT refined analysis

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