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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

22076 results found.

  1. Fermi-LAT gamma-ray observations of IceCube-240327B
  2. Fermi-LAT gamma-ray observations of IceCube-240327A
  3. Fermi GRB 240405B: Global MASTER-Net observations report
  4. LXT 240402A/GRB 240402B: GECAM-C refined analysis
  5. Swift satellite resumes pointed science observations
  6. X-ray transient LXT 240402A: WFST optical upper limits​
  7. IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
  8. GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
  9. LXT 240402A: EP-FXT detection of the X-ray afterglow
  10. Fermi GRB 240404A: Global MASTER-Net observations report
  11. LXT 240402A: MASTER optical observations with AGN in error-box
  12. X-ray transient LXT 240402A: LEIA detection
  13. Fermi trigger No 733808041: Global MASTER-Net observations report
  14. Fermi GRB 240402A: Global MASTER-Net observations report
  15. X-ray transient EP240331a: Kinder optical upper limits
  16. X-ray transient EP240331A: GRANDMA-Kilonova catcher optical upper limit
  17. EP240331A: MASTER optical observations
  18. Transient EP240315a: J-band observations of AT2024eju with WIRC
  19. X-ray transient EP20240331a: MeerLICHT optical upper limits
  20. Integral GRB240401.69: Global MASTER-Net observations report
  21. Fermi trigger No 733366352: Global MASTER-Net observations report
  22. Fermi GRB 240329A: Global MASTER-Net observations report
  23. Fermi GRB 240328B: Global MASTER-Net observations report
  24. Fermi GRB 240328A: Global MASTER-Net observations report
  25. X-ray transient EP240315a: continued ATCA monitoring
  26. IceCube-240327B: No candidates from the Zwicky Transient Facility
  27. IceCube Alert 240327.68: Global MASTER-Net observations report
  28. X-ray transient EP 240315a: Second epoch Chandra observations
  29. Fermi trigger No 733097506: Global MASTER-Net observations report
  30. X-ray transient EP240315a: e-MERLIN radio observations
  31. X-ray transient EP240315a: Ondrejov D50 optical limit
  32. Transient EPW20240219aa: REM optical/NIR further observations
  33. Fermi trigger No 733092476: Global MASTER-Net observations report
  34. Fermi trigger No 732937833: Global MASTER-Net observations report
  35. Fermi GRB 240320A: Global MASTER-Net observations report
  36. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  37. Fermi trigger No 732657380: Global MASTER-Net observations report
  38. GRB 240318A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  39. X-ray transient EP240315a: ATCA detection of radio counterpart
  40. X-ray transient EP 240315a: Chandra observations
  41. X-ray transient EP240315a: GTC/HiPERCAM photometry
  42. X-ray transient EP240315a: MeerKAT radio detection
  43. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  44. X-ray transient EP240315a: PRIME near infrared detection
  45. X-ray transient EP240315a: 3.6 m TNG NIR detection
  46. Swift satellite in safe mode
  47. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  48. Fermi GRB 240318A: Global MASTER-Net observations report
  49. GRB 240317B: Swift/BAT-GUANO arcminute localization of a burst
  50. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  51. Fermi GRB 240317B: Global MASTER-Net observations report
  52. Fermi GRB 240317A: Global MASTER-Net observations report
  53. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  54. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  55. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  56. Fermi trigger No 732299243: Global MASTER-Net observations report
  57. AT2024eju: followup observations with Liverpool Telescope suggest a fading transient
  58. X-ray transient EP240315a: ATLAS detection of a possible optical counterpart AT2024eju
  59. Einstein Probe detected of a fast X-ray transient EP240315a
  60. Fermi GRB 240314A: Global MASTER-Net observations report
  61. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  62. Fermi trigger No 731839490: Global MASTER-Net observations report
  63. Fermi-LAT gamma-ray observations of IceCube-240307A
  64. Fermi GRB 240310A: Global MASTER-Net observations report
  65. Swift GRB240309.61: Global MASTER-Net observations report
  66. Fermi trigger No 731571927: Global MASTER-Net observations report
  67. GRB 231215A: further radio observations with the VLA
  68. IceCube Alert 240307.32: Global MASTER-Net observations report
  69. Fermi GRB 240306A: Global MASTER-Net observations report
  70. Fermi GRB 240305A: Global MASTER-Net observations report
  71. GRB 240306A: Swift/BAT-GUANO detection of a burst
  72. Fermi-LAT gamma-ray observations of IceCube-240229A
  73. Swift GRB240305.18: Global MASTER-Net observations report
  74. Swift GRB240305.16: Global MASTER-Net observations report
  75. Fermi GRB 240305C: Global MASTER-Net observations report
  76. GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
  77. GRB 240218A: ALMA detection
  78. GRB 240218A: Chandra Detection and Jet Break Confirmation
  79. Fermi trigger No 731303574: Global MASTER-Net observations report
  80. Konus-Wind detection of GRB 240227A (short/hard)
  81. GRB240218A: ATCA observation of the radio counterpart
  82. Transient EPW20240219aa: Optical observations with LDT
  83. GRB 240225B: Swift-XRT afterglow detection
  84. Fermi trigger No 731161136: Global MASTER-Net observations report
  85. Swift GRB 240303A: Global MASTER-Net observations report
  86. Swift J151857.0-572147: Confirmation of a new galactic transient
  87. GRB 240215A: Swift-XRT afterglow detection
  88. GRB 240218A: NOEMA upper limit
  89. GRB 240225B: further SAO RAS optical observations
  90. Fermi GRB 240229A: Global MASTER-Net observations report
  91. IceCube Alert 240229.66: Global MASTER-Net observations report
  92. GRB 240225B: Swift ToO observations
  93. Konus-Wind detection of GRB 240225B (long)
  94. GRB 240225B: 3.6m DOT observation
  95. GRB 240225B: WINTER near-IR observations and upper limits
  96. GRB 240225B: SAO RAS optical observations
  97. GRB 240225B: Mondy afterglow observations
  98. Fermi GRB 240227A: Global MASTER-Net observations report
  99. GRB 240225B: Liverpool Telescope afterglow observations
  100. GRB 240225B: Liverpool Telescope optical afterglow observations

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