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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"

27394 results found.

  1. GRB 200519A: Swift-BAT refined analysis
  2. GRB 200519A: Insight-HXMT/HE detection
  3. GRB 200519A: Swift/UVOT Detection
  4. GRB 200519A: GROWTH-India optical follow-up
  5. GRB 200519A: AstroSat CZTI detection
  6. GRB 200519A: Swift-XRT refined Analysis
  7. GRB 200519A: Enhanced Swift-XRT position
  8. GRB 200519A: LCO Optical Afterglow Detection
  9. Fermi GBM Sub-Threshold Detection of GRB 200517A
  10. GRB 200519A: iTelescope optical afterglow detection
  11. GRB 200519A: Swift detection of a burst with an optical afterglow
  12. GRB 200517A: Swift-XRT afterglow detection
  13. GRB 200517A: MAXI/GSC detection
  14. GRB 200514B: BALROG localization (Fermi Trigger 611140062 / GRB 200514380)
  15. Swift GRB200516.63: Global MASTER-Net observations report
  16. Swift Detection of a burst from SGR Swift J1818.0-1607
  17. GRB 200514B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 611140062) - More Candidates
  18. GRB 200514A: MITSuME Akeno optical upper limits
  19. GRB 200512A: Swift-BAT refined analysis
  20. GRB 200514B: GROWTH-India follow-up of ZTF20aazpphd (AT2020jww)
  21. GRB 200514A: MAXI/GSC detection
  22. Baksan Neutrino Observatory Alert 200512.: Global MASTER-Net observations report
  23. GRB 200512A: LCO Optical Upper Limits
  24. IceCube-200512A: Upper limits from a search for additional neutrino events in IceCube
  25. Fermi GBM Sub-Threshold Detection of GRB 200512A
  26. GRB 200512A: Swift/UVOT Upper Limits
  27. GRB 200512A: Swift-XRT refined Analysis
  28. GRB 200512A: Enhanced Swift-XRT position
  29. GRB 200512A: Swift detection of a burst
  30. Fermi-LAT Gamma-ray Observations of IceCube-200512A
  31. IceCube-200512A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  32. Insight-HXMT's continued observation plan for SGR J1935+2154
  33. Konus-Wind observation of SGR 1935+2154 activity on 2020 May 10
  34. IPN triangulation of a bright burst from SGR 1935+2154 on 2020-05-10 at 06:12 UT
  35. GRB 200509A: Swift-BAT refined analysis
  36. GRB 200510A: BALROG localization (Fermi Trigger 610800081 / GRB 200510445)
  37. GRB 200509A: GROWTH-India r band upper limits
  38. GRB 200509A: Swift/UVOT Detection
  39. GRB 200509A: LCO Optical Afterglow Detection
  40. GRB 200509A: Swift-XRT refined Analysis
  41. GRB 200509A: Enhanced Swift-XRT position
  42. GRB 200509A: Zadko observatory - Gingin optical upper limits
  43. GRB 200509A: Swift detection of a burst with a possible optical counterpart
  44. FRB/X-ray bursts from SGR 1935+2154: No Neutrino Counterpart in ANTARES data
  45. Swift Detection of a burst from SGR Swift J1818.0-1607
  46. Swift GRB200506.73: Global MASTER-Net observations report
  47. Insight-HXMT detection of a short bright burst from SGR 1935+2154
  48. GRB 200502A: AstroSat CZTI detection
  49. GRB 200503B: BALROG localization (Fermi Trigger 610219118 / GRB 200503721)
  50. Insight-HXMT X-ray and hard X-ray upper limits to the radio burst detected by FAST from SGR 1935+2154
  51. No optical bursts detected from SGR J1935+2154 by 24 fps observations with Tomo-e Gozen
  52. GRB 200424A: Swift-XRT afterglow detection
  53. Insight-HXMT X-ray and hard X-ray detection of the double peaks of the Fast Radio Burst from SGR 1935+2154
  54. Fermi GBM observation of a flare from the magnetar SGR 1806-20
  55. GRB 200501A: Fermi GBM Final Real-time Localization
  56. SGR 1935+2154: INTEGRAL hard X-ray counterpart of radio burst
  57. Konus-Wind observation of a very intense bursting activity of SGR 1935+2154
  58. A Forest of Bursts from SGR 1935+2154
  59. SGR 1935+2154 the Insight-HXMT observation plan
  60. IceCube-200425A: No significant detection in HAWC
  61. IceCube-200425A: Upper limits from a search for additional neutrino events in IceCube
  62. Fermi-LAT Gamma-ray Observations of IceCube-200425A
  63. IceCube-200425A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  64. GRB 200425A: Swift-BAT refined analysis
  65. GRB 200424A: Swift/UVOT Upper Limits
  66. GRB 200425A: LCO Optical Upper Limits
  67. GRB 200425A: Swift/UVOT Upper Limits
  68. GRB 200424A: AstroSat CZTI detection
  69. GRB 200425A: Swift-XRT refined Analysis
  70. GRB 200424A: Swift-XRT observations
  71. GRB 200425A: Enhanced Swift-XRT position
  72. GRB 200425A: Swift detection of a burst
  73. GRB 200424A: LCO Optical Upper Limit
  74. IPN Triangulation of a bright burst from SGR 1935+2154
  75. IceCube-200421A: Upper limits from a search for additional neutrino events in IceCube
  76. GRB 200415A: ASIM observation
  77. GRB 200410A: Liverpool Telescope First Hour Observations
  78. Fermi-LAT Gamma-ray Observations of IceCube-200421A
  79. IceCube-200421A: No Neutrino Counterpart in ANTARES data
  80. IceCube-200421A: No significant detection in HAWC
  81. IceCube-200421A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  82. GRB 200412B: continued Mondy and Terskol optical observations
  83. GRB 200412B: continued Terskol optical observations
  84. GRB 200412B: continued AbAO, Mondy, TSHAO, Terskol optical observations
  85. GRB 200410A: Optical upper limit
  86. GRB 200416A: Swift/UVOT Detection
  87. GRB 200416A: Swift-BAT refined analysis
  88. GRB 200412B: Swift XRT confirmation of afterglow and UVOT upper limits
  89. GRB 200415A: MASTER imspection and possible localisation
  90. GRB200412B: GROWTH India detection of afterglow
  91. Konus-Wind observation of GRB 200415A (a magnetar Giant Flare in Sculptor Galaxy?)
  92. GRB 200416A: Swift-XRT refined Analysis
  93. GRB 200412B: continued Tautenburg observations
  94. GRB 200416A: Fermi GBM observation
  95. GRB 200416A: Swift detection of a burst with an optical afterglow
  96. GRB 200415A: Fermi GBM observation
  97. IPN triangulation of GRB 200415A (possible Magnetar Giant Flare in Sculptor Galaxy?)
  98. GRB 200412B: Mondy optical observations
  99. GRB 200412B: continued Tautenburg observations
  100. GRB 200415A: BALROG localization (Fermi Trigger 608633290 / GRB 200415367)

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