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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"

21129 results found.

  1. Fermi GRB 200802A: Global MASTER-Net observations report
  2. Fermi GRB 200801A: Global MASTER-Net observations report
  3. Swift Detection of an SGR-like flare from AX J1846.4-0258
  4. Swift GRB200801.84: Global MASTER-Net observations report
  5. GRB 200729A: RT-22 observations at 36.8 GHz
  6. GRB 200729A: VLA Observations
  7. GRB 200729A: Swift/UVOT Upper Limits
  8. GRB 200729A: HST imaging
  9. GRB 200729A: NOT optical upper limits
  10. GRB200729A: BOOTES-1 optical upper limit
  11. Swift GRB 200729A: Global MASTER-Net observations report
  12. GRB 200729A: Swift detection of a burst
  13. IceCube Alert 200728.35: Global MASTER-Net observations report
  14. Baksan Neutrino Observatory Alert 200726.66: Global MASTER-Net observations report
  15. GRB 200723A: ATLAS observations of GOTO candidate AT2020qer
  16. GRB 200723A: Swift ToO observations
  17. GRB 200723A: GOTO candidate afterglow and host galaxy
  18. Fermi GRB 200723A: Global MASTER-Net observations report
  19. GRB 200716C: Kitab optical observations
  20. GRB 200716C: CrAO, Terskol, Assy-Turgen optical observations
  21. GRB 200714E: Swift-XRT afterglow detection
  22. Fermi GRB 200718A: Global MASTER-Net observations report
  23. GRB 200716C: Optical observations from HCT
  24. Fermi GRB 200716A: Global MASTER-Net observations report
  25. GRB 200522A: HST NIR counterpart confirmation
  26. Swift GRB200716.96: Global MASTER-Net observations report
  27. Fermi GRB 200716B: Global MASTER-Net observations report
  28. GRB 200715A: Swift-XRT afterglow detection
  29. GRB 200715A: Swift ToO observations
  30. GRB 200714E: Swift-XRT observations
  31. Fermi GRB 200714E: Global MASTER-Net observations report
  32. GRB 200714E: Swift ToO observations
  33. GRB 200714E: Swift/BAT-GUANO detection and arcminute localization
  34. Fermi GRB 200714D: Global MASTER-Net observations report
  35. Fermi GRB 200714A: Global MASTER-Net observations report
  36. GRB 200522A: Candidate Optical/nIR Counterpart from Gemini and HST Imaging
  37. Fermi trigger No 616370565: Global MASTER-Net observations report
  38. GRB 200711A: Swift/UVOT Upper Limits
  39. GRB 200711A: KAIT Optical Upper Limit
  40. Swift GRB 200711A: Global MASTER-Net observations report
  41. GRB 200709B/HAWC-200907A: Swift-XRT further observations
  42. GRB 200709B: Swift-XRT observations
  43. GRB 200709B: Tiled Swift observations
  44. Fermi trigger No 615741133: Global MASTER-Net observations report
  45. Fermi GRB 200705A: Global MASTER-Net observations report
  46. Fermi GRB 200702A: Global MASTER-Net observations report
  47. GRB 200630A: Swift/UVOT Upper Limits
  48. GRB 200623A: Swift XRT further observations
  49. Fermi trigger No 615174580: Global MASTER-Net observations report
  50. Fermi GRB 200629A: Global MASTER-Net observations report
  51. GRB 200522A: Gemini North spectroscopy of the putative host galaxy
  52. GRB 200623A: Further MMTCam Observations of XRT Source #3
  53. GRB 200623A: LBT optical observations
  54. GRB 200623A : SMA observations at Swift/XRT Source #3
  55. Fermi GRB 200626A: Global MASTER-Net observations report
  56. GRB 200625A: Swift ToO observations
  57. Fermi GRB 200625A: Global MASTER-Net observations report
  58. Updated catalog of X-ray bursts of SGR J1935+2154 from Insight-HXMT observations
  59. GRB 200623A: MMT observations at XRT Source #3
  60. GRB 200623A: Swift/UVOT Upper Limits
  61. GRB 200623A: Swift-XRT observations
  62. GRB 200623A: OAJ deep multi-color imaging, XRT #2 is pre-detected
  63. GRB 200623A: TNG optical observations
  64. Fermi GRB 200623B: Global MASTER-Net observations report
  65. GRB 200623A: Swift ToO observations
  66. GRB 200623A: Swift/BAT-GUANO detection and arcminute localization of a short GRB
  67. Fermi GRB 200623A: Global MASTER-Net observations report
  68. IceCube-200620A: INTEGRAL was inactive at the time of the event
  69. IceCube-200620A: MASTER previous detection of ZTF20abgvabi/AT2020ncr
  70. IceCube-200620A: One Candidate Counterpart from the Zwicky Transient Facility
  71. Fermi-LAT Gamma-ray Observations of IceCube-200620A
  72. GRB 200613A: Continued CrAO optical observations
  73. IceCube Alert 200620.13: Global MASTER-Net observations report
  74. GRB 200613A: CrAO optical observations
  75. GRB 200613A: R-band observations from HCT
  76. GRB 200613A: Further Liverpool Telescope observations
  77. Fermi GRB 200619B: Global MASTER-Net observations report
  78. Fermi trigger No 614239407: Global MASTER-Net observations report
  79. Fermi trigger No 614226976: Global MASTER-Net observations report
  80. GRB 200613A: continued Kitab optical observations
  81. GRB 200613A: SAO RAS optical observations
  82. Swift/UVOT Observations of IceCube 200615A
  83. GRB 200613A: Mondy optical observations
  84. Fermi trigger No 614103490: Global MASTER-Net observations report
  85. Baksan Neutrino Observatory Alert 200617.47: Global MASTER-Net observations report
  86. Swift-XRT observations of IceCube 200615A
  87. GRB 200613A: Jet-break from Xinglong-2.16m optical observations
  88. Fermi-LAT Gamma-ray Observations of IceCube-200615A
  89. Fermi-LAT Gamma-ray Observations of IceCube-200614A and detection of a new gamma-ray source, Fermi J0202.8+3132
  90. Fermi GRB 200616A: Global MASTER-Net observations report
  91. GRB 200613A: continued AbAO optical afterglow observations
  92. IceCube-200615A: Upper limits from Fermi-GBM Observations
  93. IceCube Alert 200615.62: Global MASTER-Net observations report
  94. GRB 200613A: Continued Xinglong-2.16m optical observations
  95. Fermi GRB 200615A: Global MASTER-Net observations report
  96. Baksan Neutrino Observatory Alert 200614.34: Global MASTER-Net observations report
  97. IceCube Alert 200614.53: Global MASTER-Net observations report
  98. GRB 200613A: Swift/UVOT Detection
  99. GRB 200613A: Xinglong-2.16m optical observations
  100. Fermi GRB 200614A: Global MASTER-Net observations report

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