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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"

32720 results found.

  1. Swift satellite resumes pointed science observations
  2. GRB 240403A: Glowbug gamma-ray detection
  3. LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
  4. X-ray transient LXT 240402A: WFST optical upper limits​
  5. Konus-Wind detection of LXT 240402A/GRB 240402B
  6. GRB/FXT 240402B: Kinder optical counterpart candidate
  7. IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
  8. GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
  9. X-ray transient LXT240402A: AST3-3 optical upper limits
  10. LXT 240402A: EP-FXT detection of the X-ray afterglow
  11. Fermi GRB 240404A: Global MASTER-Net observations report
  12. LXT 240402A: MASTER optical observations with AGN in error-box
  13. GRB 240402B: GWAC-F50A optical upper limit
  14. GRB 240402B: GECAM-C detection
  15. Fermi GRB 240402A: Global MASTER-Net observations report
  16. X-ray transient EP240331a: Kinder optical upper limits
  17. X-ray transient EP240331A: GRANDMA-Kilonova catcher optical upper limit
  18. EP240331A: MASTER optical observations
  19. Transient EP240315a: J-band observations of AT2024eju with WIRC
  20. IceCube-240327B: Upper limits from a search for additional neutrino events in IceCube
  21. IceCube-240327A: Upper limits from a search for additional neutrino events in IceCube
  22. GRB 240329A: Glowbug gamma-ray detection
  23. GRB 240331A: AstroSat CZTI detection
  24. GRB 240329A: AstroSat CZTI detection
  25. GRB 240329A: GRBAlpha detection
  26. Fermi GRB 240329A: Global MASTER-Net observations report
  27. Fermi GRB 240328B: Global MASTER-Net observations report
  28. Fermi GRB 240328A: Global MASTER-Net observations report
  29. X-ray transient EP240315a: continued ATCA monitoring
  30. IceCube-240327B: No candidates from the Zwicky Transient Facility
  31. X-ray transient EP 240315a: Second epoch Chandra observations
  32. X-ray transient EP240315a: e-MERLIN radio observations
  33. X-ray transient EP240315a: Ondrejov D50 optical limit
  34. Transient EPW20240219aa: REM optical/NIR further observations
  35. GRB 240320A: Glowbug gamma-ray detection
  36. GRB 240318A: Fermi GBM Observation
  37. Fermi GRB 240320A: Global MASTER-Net observations report
  38. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  39. GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
  40. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  41. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  42. X-ray transient EP 240315a: Chandra observations
  43. X-ray transient EP240315a: GTC/HiPERCAM photometry
  44. X-ray transient EP240315a: MeerKAT radio detection
  45. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  46. GRB 240318A: Glowbug gamma-ray detection
  47. X-ray transient EP240315a: PRIME near infrared detection
  48. GRB 240317B: Fermi GBM Observation
  49. X-ray transient EP240315a: 3.6 m TNG NIR detection
  50. Swift satellite in safe mode
  51. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  52. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  53. Fermi GRB 240318A: Global MASTER-Net observations report
  54. GRB 240317A: AstroSat CZTI detection
  55. X-ray transient EP240315a: Kitab observatory optical upper limitns
  56. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  57. Fermi GRB 240317B: Global MASTER-Net observations report
  58. Fermi GRB 240317A: Global MASTER-Net observations report
  59. X-ray transient EP240315a: orphan FXT?
  60. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  61. X-ray transient EP240315a: GROND J-band detection
  62. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  63. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  64. AT2024eju: followup observations with Liverpool Telescope suggest a fading transient
  65. X-ray transient EP240315a: ATLAS detection of a possible optical counterpart AT2024eju
  66. GRID detection of GRB 240306A
  67. Changes to the Fermi-GBM Triggering Thresholds
  68. Fermi GRB 240314A: Global MASTER-Net observations report
  69. GRB240204A: VIRT optical upper limit
  70. GRB 240312A: Glowbug gamma-ray detection
  71. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  72. Fermi-LAT gamma-ray observations of IceCube-240307A
  73. Fermi GRB 240310A: Global MASTER-Net observations report
  74. IceCube-240307A: Upper limits from a search for additional neutrino events in IceCube
  75. GRID detection of GRB 240229A (Updated Report)
  76. GRID detection of GRB 240229A
  77. GRB 231215A: further radio observations with the VLA
  78. GRB 240306A: Fermi GBM observation
  79. GRB 240229A: Glowbug gamma-ray detection
  80. GRB 240227A (short): Glowbug gamma-ray detection
  81. GRB 240229A: GRBAlpha detection
  82. Konus-Wind detection of GRB 231118A
  83. GRB 240306A: AstroSat CZTI detection
  84. Fermi GRB 240306A: Global MASTER-Net observations report
  85. Fermi GRB 240305A: Global MASTER-Net observations report
  86. GRB 240305A: Fermi GBM observation
  87. Fermi-LAT gamma-ray observations of IceCube-240229A
  88. GRB 240305C: AstroSat CZTI detection of a short burst
  89. Fermi GRB 240305C: Global MASTER-Net observations report
  90. GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
  91. GRB 240218A: ALMA detection
  92. GRB 240218A: Chandra Detection and Jet Break Confirmation
  93. Konus-Wind detection of GRB 240227A (short/hard)
  94. GRB 240303B: VZLUSAT-2 detection
  95. GRB 240229A: VZLUSAT-2 detection
  96. Improved IPN triangulation of GRB 240227A (short)
  97. IPN triangulation of GRB 240229A
  98. GRB240218A: ATCA observation of the radio counterpart
  99. Transient EPW20240219aa: Optical observations with LDT
  100. Konus-Wind detection of GRB 240303B

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