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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"

24810 results found.

  1. GRB 200524A: MITSuME Akeno optical observation
  2. GRB 200524A: Swift-XRT afterglow detection
  3. GRB 200524A: OAJ multicolor afterglow detection
  4. GRB 200524A: Fermi GBM detection
  5. GRB 200524: Swift/UVOT observations missed the ZTF20abbiixp position
  6. GRB 200524A: CAHA multicolor afterglow detection
  7. GRB 200524A: Correction to the GCN 27800
  8. GRB 200524A: 3.6m DOT observations of the afterglow candidate ZTF20abbiixp
  9. GRB 200524A: GROWTH-India confirmation of optical afterglow
  10. GRB 200522A: Swift-BAT refined analysis
  11. GRB 200522A: LCO Optical Afterglow Detection
  12. GRB 200522A: 6 GHz VLA radio source detection
  13. GRB 200522A: Swift-XRT refined Analysis
  14. GRB 200522A: Swift/UVOT Upper Limits
  15. GRB 200522A: Enhanced Swift-XRT position
  16. GRB 200522A: Swift detection of a short burst
  17. GRB 200519A: Swift-BAT refined analysis
  18. GRB 200519A: Insight-HXMT/HE detection
  19. GRB 200519A: Swift/UVOT Detection
  20. GRB 200519A: GROWTH-India optical follow-up
  21. GRB 200519A: AstroSat CZTI detection
  22. GRB 200519A: Swift-XRT refined Analysis
  23. GRB 200519A: Enhanced Swift-XRT position
  24. GRB 200519A: LCO Optical Afterglow Detection
  25. Fermi GBM Sub-Threshold Detection of GRB 200517A
  26. GRB 200519A: iTelescope optical afterglow detection
  27. GRB 200519A: Swift detection of a burst with an optical afterglow
  28. GRB 200517A: Swift-XRT afterglow detection
  29. GRB 200517A: MAXI/GSC detection
  30. GRB 200514B: BALROG localization (Fermi Trigger 611140062 / GRB 200514380)
  31. Swift GRB200516.63: Global MASTER-Net observations report
  32. Swift Detection of a burst from SGR Swift J1818.0-1607
  33. GRB 200514B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 611140062) - More Candidates
  34. GRB 200514A: MITSuME Akeno optical upper limits
  35. GRB 200512A: Swift-BAT refined analysis
  36. GRB 200514B: GROWTH-India follow-up of ZTF20aazpphd (AT2020jww)
  37. GRB 200514A: MAXI/GSC detection
  38. Baksan Neutrino Observatory Alert 200512.: Global MASTER-Net observations report
  39. GRB 200512A: LCO Optical Upper Limits
  40. IceCube-200512A: Upper limits from a search for additional neutrino events in IceCube
  41. Fermi GBM Sub-Threshold Detection of GRB 200512A
  42. GRB 200512A: Swift/UVOT Upper Limits
  43. GRB 200512A: Swift-XRT refined Analysis
  44. GRB 200512A: Enhanced Swift-XRT position
  45. GRB 200512A: Swift detection of a burst
  46. Fermi-LAT Gamma-ray Observations of IceCube-200512A
  47. IceCube-200512A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  48. Insight-HXMT's continued observation plan for SGR J1935+2154
  49. Konus-Wind observation of SGR 1935+2154 activity on 2020 May 10
  50. IPN triangulation of a bright burst from SGR 1935+2154 on 2020-05-10 at 06:12 UT
  51. GRB 200509A: Swift-BAT refined analysis
  52. GRB 200510A: BALROG localization (Fermi Trigger 610800081 / GRB 200510445)
  53. GRB 200509A: GROWTH-India r band upper limits
  54. GRB 200509A: Swift/UVOT Detection
  55. GRB 200509A: LCO Optical Afterglow Detection
  56. GRB 200509A: Swift-XRT refined Analysis
  57. GRB 200509A: Enhanced Swift-XRT position
  58. GRB 200509A: Zadko observatory - Gingin optical upper limits
  59. GRB 200509A: Swift detection of a burst with a possible optical counterpart
  60. FRB/X-ray bursts from SGR 1935+2154: No Neutrino Counterpart in ANTARES data
  61. Swift Detection of a burst from SGR Swift J1818.0-1607
  62. Swift GRB200506.73: Global MASTER-Net observations report
  63. Insight-HXMT detection of a short bright burst from SGR 1935+2154
  64. GRB 200502A: AstroSat CZTI detection
  65. GRB 200503B: BALROG localization (Fermi Trigger 610219118 / GRB 200503721)
  66. Insight-HXMT X-ray and hard X-ray upper limits to the radio burst detected by FAST from SGR 1935+2154
  67. No optical bursts detected from SGR J1935+2154 by 24 fps observations with Tomo-e Gozen
  68. GRB 200424A: Swift-XRT afterglow detection
  69. Insight-HXMT X-ray and hard X-ray detection of the double peaks of the Fast Radio Burst from SGR 1935+2154
  70. Fermi GBM observation of a flare from the magnetar SGR 1806-20
  71. GRB 200501A: Fermi GBM Final Real-time Localization
  72. SGR 1935+2154: INTEGRAL hard X-ray counterpart of radio burst
  73. Konus-Wind observation of a very intense bursting activity of SGR 1935+2154
  74. A Forest of Bursts from SGR 1935+2154
  75. SGR 1935+2154 the Insight-HXMT observation plan
  76. IceCube-200425A: No significant detection in HAWC
  77. IceCube-200425A: Upper limits from a search for additional neutrino events in IceCube
  78. Fermi-LAT Gamma-ray Observations of IceCube-200425A
  79. IceCube-200425A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  80. GRB 200425A: Swift-BAT refined analysis
  81. GRB 200424A: Swift/UVOT Upper Limits
  82. GRB 200425A: LCO Optical Upper Limits
  83. GRB 200425A: Swift/UVOT Upper Limits
  84. GRB 200424A: AstroSat CZTI detection
  85. GRB 200425A: Swift-XRT refined Analysis
  86. GRB 200424A: Swift-XRT observations
  87. GRB 200425A: Enhanced Swift-XRT position
  88. GRB 200425A: Swift detection of a burst
  89. GRB 200424A: LCO Optical Upper Limit
  90. IPN Triangulation of a bright burst from SGR 1935+2154
  91. IceCube-200421A: Upper limits from a search for additional neutrino events in IceCube
  92. GRB 200415A: ASIM observation
  93. GRB 200410A: Liverpool Telescope First Hour Observations
  94. Fermi-LAT Gamma-ray Observations of IceCube-200421A
  95. IceCube-200421A: No Neutrino Counterpart in ANTARES data
  96. IceCube-200421A: No significant detection in HAWC
  97. IceCube-200421A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  98. GRB 200412B: continued Mondy and Terskol optical observations
  99. GRB 200412B: continued Terskol optical observations
  100. GRB 200412B: continued AbAO, Mondy, TSHAO, Terskol optical observations

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