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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"

32685 results found.

  1. GRB 240318A: Fermi GBM Observation
  2. Fermi GRB 240320A: Global MASTER-Net observations report
  3. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  4. GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
  5. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  6. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  7. X-ray transient EP 240315a: Chandra observations
  8. X-ray transient EP240315a: GTC/HiPERCAM photometry
  9. X-ray transient EP240315a: MeerKAT radio detection
  10. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  11. GRB 240318A: Glowbug gamma-ray detection
  12. X-ray transient EP240315a: PRIME near infrared detection
  13. GRB 240317B: Fermi GBM Observation
  14. X-ray transient EP240315a: 3.6 m TNG NIR detection
  15. Swift satellite in safe mode
  16. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  17. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  18. Fermi GRB 240318A: Global MASTER-Net observations report
  19. GRB 240317A: AstroSat CZTI detection
  20. X-ray transient EP240315a: Kitab observatory optical upper limitns
  21. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  22. Fermi GRB 240317B: Global MASTER-Net observations report
  23. Fermi GRB 240317A: Global MASTER-Net observations report
  24. X-ray transient EP240315a: orphan FXT?
  25. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  26. X-ray transient EP240315a: GROND J-band detection
  27. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  28. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  29. AT2024eju: followup observations with Liverpool Telescope suggest a fading transient
  30. X-ray transient EP240315a: ATLAS detection of a possible optical counterpart AT2024eju
  31. GRID detection of GRB 240306A
  32. Changes to the Fermi-GBM Triggering Thresholds
  33. Fermi GRB 240314A: Global MASTER-Net observations report
  34. GRB240204A: VIRT optical upper limit
  35. GRB 240312A: Glowbug gamma-ray detection
  36. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  37. Fermi-LAT gamma-ray observations of IceCube-240307A
  38. Fermi GRB 240310A: Global MASTER-Net observations report
  39. IceCube-240307A: Upper limits from a search for additional neutrino events in IceCube
  40. GRID detection of GRB 240229A (Updated Report)
  41. GRID detection of GRB 240229A
  42. GRB 231215A: further radio observations with the VLA
  43. GRB 240306A: Fermi GBM observation
  44. GRB 240229A: Glowbug gamma-ray detection
  45. GRB 240227A (short): Glowbug gamma-ray detection
  46. GRB 240229A: GRBAlpha detection
  47. Konus-Wind detection of GRB 231118A
  48. GRB 240306A: AstroSat CZTI detection
  49. Fermi GRB 240306A: Global MASTER-Net observations report
  50. Fermi GRB 240305A: Global MASTER-Net observations report
  51. GRB 240305A: Fermi GBM observation
  52. Fermi-LAT gamma-ray observations of IceCube-240229A
  53. GRB 240305C: AstroSat CZTI detection of a short burst
  54. Fermi GRB 240305C: Global MASTER-Net observations report
  55. GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
  56. GRB 240218A: ALMA detection
  57. GRB 240218A: Chandra Detection and Jet Break Confirmation
  58. Konus-Wind detection of GRB 240227A (short/hard)
  59. GRB 240303B: VZLUSAT-2 detection
  60. GRB 240229A: VZLUSAT-2 detection
  61. Improved IPN triangulation of GRB 240227A (short)
  62. IPN triangulation of GRB 240229A
  63. GRB240218A: ATCA observation of the radio counterpart
  64. Transient EPW20240219aa: Optical observations with LDT
  65. Konus-Wind detection of GRB 240303B
  66. Swift Trigger 1218645: Another detection of Swift J151857.0-572147
  67. IPN triangulation of GRB 240303B
  68. Swift J151857.0-572147: Swift-BAT refined analysis
  69. GRB 240303B: Fermi GBM Detection
  70. GRB 240225B: Swift-XRT afterglow detection
  71. Swift detection of Swift J151857.0-572147
  72. GRB 240303B: CALET Gamma-Ray Burst Monitor detection
  73. Swift GRB 240303A: Global MASTER-Net observations report
  74. Swift J151857.0-572147: Confirmation of a new galactic transient
  75. GRB 240225B: Glowbug gamma-ray detection
  76. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  77. GRB 240225C: Glowbug gamma-ray detection
  78. GRB 240225A (short): Glowbug gamma-ray detection
  79. GRB 240229A: DDOTI Upper Limits on the Afterglow
  80. GRB 240218A: NOEMA upper limit
  81. GRB 240229A: CALET Gamma-Ray Burst Monitor detection
  82. GRB 240225B: further SAO RAS optical observations
  83. Fermi GRB 240229A: Global MASTER-Net observations report
  84. GRB 240225B: Swift ToO observations
  85. Konus-Wind detection of GRB 240225B (long)
  86. GRB 240225B: VLT/X-shooter redshift
  87. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  88. GRB 240225B: 3.6m DOT observation
  89. GRB 240225B: WINTER near-IR observations and upper limits
  90. GRB 240225B: SAO RAS optical observations
  91. GRB 240226A: GRBAlpha detection
  92. GRB 240225B: Mondy afterglow observations
  93. Fermi GRB 240227A: Global MASTER-Net observations report
  94. GRB 240225B: Liverpool Telescope afterglow observations
  95. Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
  96. IPN triangulation of GRB 240227A (short)
  97. GRB 240225B: Liverpool Telescope optical afterglow observations
  98. GRB 240225B: NOT optical observations
  99. GRB 240218A: CMO SAI NIR upper limit
  100. Fermi GRB 240226A: Global MASTER-Net observations report

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