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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"

32735 results found.

  1. EP240408a: GROND detection of a candidate counterpart
  2. EP240408a: Swift follow-up observation
  3. X-ray transient EP240315a: second epoch e-MERLIN radio observations
  4. GRB 240405A: GRBAlpha detection
  5. IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits
  6. Fermi GRB 240408A: Global MASTER-Net observations report
  7. GRB 240402C: CALET Gamma-Ray Burst Monitor detection
  8. Fermi GRB 240407A: Global MASTER-Net observations report
  9. Fermi-LAT gamma-ray observations of IceCube-240327B
  10. Fermi-LAT gamma-ray observations of IceCube-240327A
  11. LXT 240402A/GRB 240402B: rest-frame energetics from Konus-Wind observation
  12. Fermi GRB 240405B: Global MASTER-Net observations report
  13. GRB 240402C: Glowbug gamma-ray detection
  14. GRB 240331A: GRBAlpha detection
  15. LXT 240402A/GRB 240402B: GECAM-C refined analysis
  16. Swift satellite resumes pointed science observations
  17. GRB 240403A: Glowbug gamma-ray detection
  18. LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
  19. X-ray transient LXT 240402A: WFST optical upper limits​
  20. Konus-Wind detection of LXT 240402A/GRB 240402B
  21. GRB/FXT 240402B: Kinder optical counterpart candidate
  22. IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
  23. GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
  24. X-ray transient LXT240402A: AST3-3 optical upper limits
  25. LXT 240402A: EP-FXT detection of the X-ray afterglow
  26. Fermi GRB 240404A: Global MASTER-Net observations report
  27. LXT 240402A: MASTER optical observations with AGN in error-box
  28. GRB 240402B: GWAC-F50A optical upper limit
  29. GRB 240402B: GECAM-C detection
  30. Fermi GRB 240402A: Global MASTER-Net observations report
  31. X-ray transient EP240331a: Kinder optical upper limits
  32. X-ray transient EP240331A: GRANDMA-Kilonova catcher optical upper limit
  33. EP240331A: MASTER optical observations
  34. Transient EP240315a: J-band observations of AT2024eju with WIRC
  35. IceCube-240327B: Upper limits from a search for additional neutrino events in IceCube
  36. IceCube-240327A: Upper limits from a search for additional neutrino events in IceCube
  37. GRB 240329A: Glowbug gamma-ray detection
  38. GRB 240331A: AstroSat CZTI detection
  39. GRB 240329A: AstroSat CZTI detection
  40. GRB 240329A: GRBAlpha detection
  41. Fermi GRB 240329A: Global MASTER-Net observations report
  42. Fermi GRB 240328B: Global MASTER-Net observations report
  43. Fermi GRB 240328A: Global MASTER-Net observations report
  44. X-ray transient EP240315a: continued ATCA monitoring
  45. IceCube-240327B: No candidates from the Zwicky Transient Facility
  46. X-ray transient EP 240315a: Second epoch Chandra observations
  47. X-ray transient EP240315a: e-MERLIN radio observations
  48. X-ray transient EP240315a: Ondrejov D50 optical limit
  49. Transient EPW20240219aa: REM optical/NIR further observations
  50. GRB 240320A: Glowbug gamma-ray detection
  51. GRB 240318A: Fermi GBM Observation
  52. Fermi GRB 240320A: Global MASTER-Net observations report
  53. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  54. GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
  55. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  56. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  57. X-ray transient EP 240315a: Chandra observations
  58. X-ray transient EP240315a: GTC/HiPERCAM photometry
  59. X-ray transient EP240315a: MeerKAT radio detection
  60. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  61. GRB 240318A: Glowbug gamma-ray detection
  62. X-ray transient EP240315a: PRIME near infrared detection
  63. GRB 240317B: Fermi GBM Observation
  64. X-ray transient EP240315a: 3.6 m TNG NIR detection
  65. Swift satellite in safe mode
  66. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  67. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  68. Fermi GRB 240318A: Global MASTER-Net observations report
  69. GRB 240317A: AstroSat CZTI detection
  70. X-ray transient EP240315a: Kitab observatory optical upper limitns
  71. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  72. Fermi GRB 240317B: Global MASTER-Net observations report
  73. Fermi GRB 240317A: Global MASTER-Net observations report
  74. X-ray transient EP240315a: orphan FXT?
  75. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  76. X-ray transient EP240315a: GROND J-band detection
  77. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  78. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  79. AT2024eju: followup observations with Liverpool Telescope suggest a fading transient
  80. X-ray transient EP240315a: ATLAS detection of a possible optical counterpart AT2024eju
  81. GRID detection of GRB 240306A
  82. Changes to the Fermi-GBM Triggering Thresholds
  83. Fermi GRB 240314A: Global MASTER-Net observations report
  84. GRB240204A: VIRT optical upper limit
  85. GRB 240312A: Glowbug gamma-ray detection
  86. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  87. Fermi-LAT gamma-ray observations of IceCube-240307A
  88. Fermi GRB 240310A: Global MASTER-Net observations report
  89. IceCube-240307A: Upper limits from a search for additional neutrino events in IceCube
  90. GRID detection of GRB 240229A (Updated Report)
  91. GRID detection of GRB 240229A
  92. GRB 231215A: further radio observations with the VLA
  93. GRB 240306A: Fermi GBM observation
  94. GRB 240229A: Glowbug gamma-ray detection
  95. GRB 240227A (short): Glowbug gamma-ray detection
  96. GRB 240229A: GRBAlpha detection
  97. Konus-Wind detection of GRB 231118A
  98. GRB 240306A: AstroSat CZTI detection
  99. Fermi GRB 240306A: Global MASTER-Net observations report
  100. Fermi GRB 240305A: Global MASTER-Net observations report

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