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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"

21093 results found.

  1. Fermi GRB 240328B: Global MASTER-Net observations report
  2. Fermi GRB 240328A: Global MASTER-Net observations report
  3. X-ray transient EP240315a: continued ATCA monitoring
  4. IceCube-240327B: No candidates from the Zwicky Transient Facility
  5. IceCube Alert 240327.68: Global MASTER-Net observations report
  6. X-ray transient EP 240315a: Second epoch Chandra observations
  7. Fermi trigger No 733097506: Global MASTER-Net observations report
  8. X-ray transient EP240315a: e-MERLIN radio observations
  9. X-ray transient EP240315a: Ondrejov D50 optical limit
  10. Transient EPW20240219aa: REM optical/NIR further observations
  11. Fermi trigger No 733092476: Global MASTER-Net observations report
  12. Fermi trigger No 732937833: Global MASTER-Net observations report
  13. Fermi GRB 240320A: Global MASTER-Net observations report
  14. Fermi trigger No 732657380: Global MASTER-Net observations report
  15. X-ray transient EP240315a: ATCA detection of radio counterpart
  16. X-ray transient EP 240315a: Chandra observations
  17. X-ray transient EP240315a: GTC/HiPERCAM photometry
  18. X-ray transient EP240315a: MeerKAT radio detection
  19. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  20. X-ray transient EP240315a: PRIME near infrared detection
  21. Swift satellite in safe mode
  22. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  23. Fermi GRB 240318A: Global MASTER-Net observations report
  24. GRB 240317B: Swift/BAT-GUANO arcminute localization of a burst
  25. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  26. Fermi GRB 240317B: Global MASTER-Net observations report
  27. Fermi GRB 240317A: Global MASTER-Net observations report
  28. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  29. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  30. Fermi trigger No 732299243: Global MASTER-Net observations report
  31. AT2024eju: followup observations with Liverpool Telescope suggest a fading transient
  32. X-ray transient EP240315a: ATLAS detection of a possible optical counterpart AT2024eju
  33. Einstein Probe detected of a fast X-ray transient EP240315a
  34. Fermi GRB 240314A: Global MASTER-Net observations report
  35. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  36. Fermi trigger No 731839490: Global MASTER-Net observations report
  37. Fermi-LAT gamma-ray observations of IceCube-240307A
  38. Fermi GRB 240310A: Global MASTER-Net observations report
  39. Swift GRB240309.61: Global MASTER-Net observations report
  40. Fermi trigger No 731571927: Global MASTER-Net observations report
  41. GRB 231215A: further radio observations with the VLA
  42. IceCube Alert 240307.32: Global MASTER-Net observations report
  43. Fermi GRB 240306A: Global MASTER-Net observations report
  44. Fermi GRB 240305A: Global MASTER-Net observations report
  45. Fermi-LAT gamma-ray observations of IceCube-240229A
  46. Swift GRB240305.18: Global MASTER-Net observations report
  47. Swift GRB240305.16: Global MASTER-Net observations report
  48. Fermi GRB 240305C: Global MASTER-Net observations report
  49. GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
  50. GRB 240218A: ALMA detection
  51. GRB 240218A: Chandra Detection and Jet Break Confirmation
  52. Fermi trigger No 731303574: Global MASTER-Net observations report
  53. GRB240218A: ATCA observation of the radio counterpart
  54. Transient EPW20240219aa: Optical observations with LDT
  55. GRB 240225B: Swift-XRT afterglow detection
  56. Fermi trigger No 731161136: Global MASTER-Net observations report
  57. Swift GRB 240303A: Global MASTER-Net observations report
  58. Swift J151857.0-572147: Confirmation of a new galactic transient
  59. GRB 240215A: Swift-XRT afterglow detection
  60. GRB 240218A: NOEMA upper limit
  61. GRB 240225B: further SAO RAS optical observations
  62. Fermi GRB 240229A: Global MASTER-Net observations report
  63. IceCube Alert 240229.66: Global MASTER-Net observations report
  64. GRB 240225B: Swift ToO observations
  65. GRB 240225B: 3.6m DOT observation
  66. GRB 240225B: WINTER near-IR observations and upper limits
  67. GRB 240225B: SAO RAS optical observations
  68. GRB 240225B: Mondy afterglow observations
  69. Fermi GRB 240227A: Global MASTER-Net observations report
  70. GRB 240225B: Liverpool Telescope afterglow observations
  71. GRB 240225B: Liverpool Telescope optical afterglow observations
  72. GRB 240225B: NOT optical observations
  73. Fermi GRB 240226A: Global MASTER-Net observations report
  74. GRB 240225B: Swift-XRT observations
  75. Transient EPW20240219aa: Kp-band imaging observations with NIRES
  76. Transient EPW20240219aa: J-band upper limits from WINTER
  77. GRB 240225B: GOTO detection of a candidate optical afterglow
  78. Transient EPW20240219aa: REM optical/NIR upper limits
  79. GRB 240222A: ATCA radio observations
  80. Fermi trigger No 730618809: Global MASTER-Net observations report
  81. GRB 240225B: Tiled Swift observations
  82. GRB 240218A: VLA detection
  83. Transient EPW20240219aa: 7DT Optical Upper Limits
  84. VLA X-band observation of EPW20240219aa
  85. Transient EPW20240219aa: Mondy optical observations
  86. Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
  87. GRB 240222A: Swift/UVOT Upper Limits
  88. Swift GRB 240222A: Global MASTER-Net observations report
  89. Fermi GRB 240222A: Global MASTER-Net observations report
  90. GRB 240222A: REM optical and NIR early-time observations
  91. Swift GRB240221.92: Global MASTER-Net observations report
  92. GRB 240218A: MeerLICHT upper limits
  93. GRB 240218A: LBT H-band detection
  94. Fermi GRB 240220A: Global MASTER-Net observations report
  95. Fermi trigger No 729914426: Global MASTER-Net observations report
  96. GRB 240218A: VLT/FORS2 z-band detection
  97. GRB 240218A: REM detection of a NIR afterglow candidate
  98. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  99. Swift GRB240218.08: Global MASTER-Net observations report
  100. Fermi GRB 240216A: Global MASTER-Net observations report

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