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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.

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

32687 results found.

  1. GRB 250330B: EIRSAT-1 GMOD Detection
  2. GRB 250327A Swift-BAT refined analysis
  3. LIGO/Virgo/KAGRA S250331o: Updated Sky localization
  4. GRB 250329A: AbAO, Mondy and SAO RAS optical upper limits
  5. GRB 250331D: Swift ToO observations
  6. Swift GRB 250331C: Global MASTER-Net observations report
  7. Swift GRB 250331B: Global MASTER-Net observations report
  8. GRB 250331D: Swift/BAT-GUANO arcminute localization of a burst during slew
  9. Konus-Wind detection of GRB 250327B
  10. IceCube-250330A: Upper limits from a search for additional neutrino events in IceCube
  11. GRB 250329B: Swift-XRT confirmation of fading
  12. GRB 250330A: VLT/FORS2 Afterglow Detection
  13. GRB20250327B: 45th Parallel Observatory upper limit
  14. GRB 250328A: Swift/UVOT Detection
  15. GRB 250328A: Swift-XRT refined Analysis
  16. Fermi-LAT gamma-ray observations of IceCube-250330A
  17. SVOM/sb25033102 is a false trigger
  18. GRB 250330A: Fermi GBM Observation
  19. GRB 250331C: COLIBRÍ/DDRAGO optical upper limit
  20. GRB 250331B: COLIBRÍ/DDRAGO optical upper limit
  21. GRB 250330A: SVOM/VT optical upper limit
  22. GRB 250314A: VLA detection
  23. LIGO/Virgo/KAGRA S250331o: Identification of a GW compact binary merger candidate
  24. Fermi GRB 250330B: Global MASTER-Net observations report
  25. Fermi GRB 250330A: Global MASTER-Net observations report
  26. GRB 250330A: BOOTES-7 early optical upper limit
  27. GRB 250330A: Swift/UVOT Upper Limits
  28. GRB 250328A: 1.6m Mephisto optical observations
  29. GRB 250329B: SVOM/COLIBRÍ (F-GFT) optical upper limit
  30. GRB 250330A: Fermi GBM Final Localization
  31. GRB 250330A: VLT/FORS2 Optical Observations
  32. GRB 250330A: Prompt Swift-XRT position
  33. GRB 250328A: A fading optical afterglow confirmed by SVOM/VT
  34. GRB 250329B: SVOM/C-GFT optical upper limit
  35. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Epoch 1)
  36. GRB 250327B: ALMA detection
  37. GRB 250327B: VLA detection
  38. GRB 250329B: SVOM/VT optical upper limit
  39. GRB 250327B: SVOM/COLIBRÍ (F-GFT) Further Observations
  40. GRB 250329B: 1.6m Mephisto Optical Upper Limits
  41. GRB250329A: REM optical afterglow detection
  42. GRB 250329B: GWAC-F50A optical upper limit
  43. GRB 250329A: Swift-XRT afterglow detection
  44. GRB 250328A: SVOM/VT optical observation
  45. GRB 250329A: Fading optical counterpart detection by LCO.
  46. GRB 250328A: SVOM/C-GFT optical upper limit
  47. GRB 250328A: SVOM/COLIBRÍ (F-GFT) optical afterglow candidate
  48. GRB 250328A: VLT/HAWK-I near-infrared afterglow candidate
  49. GRB 250329A: VLT/X-shooter redshift z = 2.921
  50. GRB 250329A: SVOM/VT optical counterpart confirmation
  51. GRB 250327B: J-band observations with WINTER
  52. GRB 250327B: MASTER detection of OT rebrightening
  53. GRB 250327B: LCO optical counterpart detection
  54. GRB 250328A: GWAC-F50A optical upper limit
  55. FRB 20250316A: FTW optical observations
  56. EP250302a: SPI-ACS/INTEGRAL Upper Limit
  57. GRB 250327B: CrAO and SAO RAS Optical Observations
  58. GRB 250327B: OHP/T193 spectroscopic observations and redshift confirmation
  59. GRB 250327B: further optical observations by LCOGT
  60. EP250315a: Pan-STARRS r and i-band imaging and photometry
  61. GRB 250327b: Liverpool Telescope optical observations
  62. GRB 250322A: GRANDMA/TNOT optical upper limits
  63. LIGO/Virgo/KAGRA S250328ae: Updated Sky localization
  64. GRB 250327A: SVOM/VT upper limits on the XRT position
  65. LIGO/Virgo/KAGRA S250328ae: Identification of a GW compact binary merger candidate
  66. GRB 250327B: SVOM/COLIBRÍ (F-GFT) follow-up observations
  67. GRB 250327B: Las Cumbres optical counterpart detection
  68. GRB 250327B: Swift-XRT detection of the X-ray afterglow
  69. GRB 250327B: 1.6m Mephisto optical observations
  70. GRB 250327B: NOT spectroscopic redshift z = 3.035
  71. GRB 250327B: GOTO optical counterpart detection
  72. GRB 250327B: SVOM/VT optically bright counterpart
  73. GRB 250327B: SAO RAS optical candidate
  74. FRB 20250316A: Gemini Imaging and Spectroscopy of the Sub-arcsecond Localization Region of FRB 20250316A
  75. GRB 250327A: J-band observations with WINTER
  76. GRB 250327A: SVOM/VT optical candidate
  77. FRB 20250316A: Pan-STARRS r and i-band imaging and photometry
  78. GRB 250327A: Fermi GBM observation
  79. Fermi GRB 250327A: Global MASTER-Net observations report
  80. Swift GRB 250327A: Global MASTER-Net observations report
  81. GRB 250327A: DDOTI Optical Observations
  82. GRB 250327A: COLIBRÍ optical upper limit
  83. GRB 250327A: Swift detection of a burst
  84. LIGO/Virgo/KAGRA S250326y: Updated Sky localization
  85. Konus-Wind detection of GRB 250322A (short)
  86. IPN triangulation of GRB 250322B
  87. LIGO/Virgo/KAGRA S250326y: Identification of a GW compact binary merger candidate
  88. EP250321a: Mondy AZT-33IK Continued Optical Observations
  89. GRB 250322A: third epoch of NOT optical observations
  90. GRB 250322A: Swift-BAT refined analysis
  91. GRB 250321B: ISON-Kitab RC-36 Optical Upper Limit
  92. FRB 250316A: NOT optical upper limit for the X ray source EP J120944.2+585060
  93. GRB 250322A: further NOT optical observations
  94. EP-WXT trigger 01709133021: Optical upper limit through Kinder observations
  95. GRB 250322A: Swift/UVOT Upper Limits
  96. GRB 250322A: VLT/X-shooter redshift confirmation of the putative host galaxy
  97. FRB 250316A: COLIBRÍ/DDRAGO Optical follow up of the X ray source EP J120944.2+585060
  98. GRB 250322B: NuSTAR detection of the prompt emission and regular dips during the burst
  99. EP250321a: TNOT Observation of Optical Counterpart
  100. FRB 250316A: DDOTI Continued Optical Observations (Third Epoch)

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