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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"

45776 results found.

  1. GRB 250331D: Swift-XRT observations
  2. GRB 250331C: Swift-XRT refined Analysis
  3. GRB 250331B: Swift-XRT refined Analysis
  4. GRB 250331B: Swift-XRT refined Analysis
  5. GRB 250322B possible detection by the AstroSat Satellite
  6. GRB 250330B: SVOM/GRM observation of a short burst
  7. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Epoch 2)
  8. Fermi GRB 250331E: Global MASTER-Net observations report
  9. Fermi GRB 250331D: Global MASTER-Net observations report
  10. GRB 250330B: EIRSAT-1 GMOD Detection
  11. GRB 250331E: Fermi GBM Final Real-time Localization
  12. GRB 250327A Swift-BAT refined analysis
  13. LIGO/Virgo/KAGRA S250331o: Updated Sky localization
  14. GRB 250329A: AbAO, Mondy and SAO RAS optical upper limits
  15. Fermi trigger No 765078057: Global MASTER-Net observations report
  16. GRB 250329B: CAHA 2.2m telescope optical limit
  17. GRB 250331D: Swift ToO observations
  18. Swift GRB 250331C: Global MASTER-Net observations report
  19. Swift GRB 250331B: Global MASTER-Net observations report
  20. GRB 250331D: Swift/BAT-GUANO arcminute localization of a burst during slew
  21. Konus-Wind detection of GRB 250327B
  22. GRB 250331C: Enhanced Swift-XRT position
  23. IceCube-250330A: Upper limits from a search for additional neutrino events in IceCube
  24. LIGO/Virgo/KAGRA S250331o: NED Galaxies in the 3-Initial Localization Volume
  25. GRB 250331B: Enhanced Swift-XRT position
  26. GRB 250320C : SVOM detection of a burst through offline search
  27. LIGO/Virgo/KAGRA S250328ae: Swift XRT observations, 34 possible X-ray sources
  28. GRB 250329B: Swift-XRT confirmation of fading
  29. GRB 250330A: VLT/FORS2 Afterglow Detection
  30. GRB20250327B: 45th Parallel Observatory upper limit
  31. GRB 250328A: Swift/UVOT Detection
  32. GRB 250328A: Swift-XRT refined Analysis
  33. Fermi-LAT gamma-ray observations of IceCube-250330A
  34. SVOM/sb25033102 is a false trigger
  35. GRB 250330A: Fermi GBM Observation
  36. GRB 250331C: COLIBRÍ/DDRAGO optical upper limit
  37. GRB 250331B: COLIBRÍ/DDRAGO optical upper limit
  38. GRB 250331D: Fermi GBM Final Real-time Localization
  39. GRB 250331C: Prompt enhanced Swift-XRT position
  40. GRB 250331C: Swift detection of a burst
  41. GRB 250331B: Swift detection of a burst
  42. GRB 250330A: SVOM/VT optical upper limit
  43. GRB 250331A: MAXI/GSC detection
  44. SVOM/sb25033102: SVOM detection of an X-ray transient
  45. GRB 250314A: VLA detection
  46. LIGO/Virgo/KAGRA S250331o: Identification of a GW compact binary merger candidate
  47. Fermi GRB 250330B: Global MASTER-Net observations report
  48. GRB 250330B: Fermi GBM Final Real-time Localization
  49. Fermi GRB 250330A: Global MASTER-Net observations report
  50. GRB 250330A: BOOTES-7 early optical upper limit
  51. GRB 250330A: Swift/UVOT Upper Limits
  52. GRB 250330A: Swift-XRT afterglow detection
  53. GRB 250328A: 1.6m Mephisto optical observations
  54. GRB 250329B: SVOM/COLIBRÍ (F-GFT) optical upper limit
  55. GRB 250330A: Fermi GBM Final Localization
  56. IceCube-250330A - IceCube observation of a high-energy neutrino candidate track-like event
  57. IceCube Alert 250330.35: Global MASTER-Net observations report
  58. GRB 250330A: VLT/FORS2 Optical Observations
  59. GRB 250330A: Prompt Swift-XRT position
  60. GRB 250329B: Swift-XRT afterglow detection
  61. GRB 250330A: Swift detection of a burst
  62. Swift GRB250330.26: Global MASTER-Net observations report
  63. GRB 250328A: A fading optical afterglow confirmed by SVOM/VT
  64. GRB 250329B: SVOM/C-GFT optical upper limit
  65. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Epoch 1)
  66. GRB 250327B: ALMA detection
  67. GRB 250327B: VLA detection
  68. GRB 250329B: SVOM/VT optical upper limit
  69. GRB 250327B: SVOM/COLIBRÍ (F-GFT) Further Observations
  70. GRB 250329B: 1.6m Mephisto Optical Upper Limits
  71. LIGO/Virgo/KAGRA S250329fl: 2 counterpart neutrino candidate events from an IceCube neutrino search
  72. GRB250329A: REM optical afterglow detection
  73. GRB 250329B: GWAC-F50A optical upper limit
  74. GRB 250329B: SVOM detection of a faint transient
  75. GRB 250329A: Swift-XRT afterglow detection
  76. GRB 250328A: SVOM/VT optical observation
  77. GRB 250329A: Fading optical counterpart detection by LCO.
  78. GRB 250328A: SVOM/C-GFT optical upper limit
  79. GRB 250328A: SVOM/COLIBRÍ (F-GFT) optical afterglow candidate
  80. GRB 250328A: VLT/HAWK-I near-infrared afterglow candidate
  81. GRB 250329A: VLT/X-shooter redshift z = 2.921
  82. GRB 250329A: SVOM/VT optical counterpart confirmation
  83. GRB 250329A: SVOM detection of a burst
  84. GRB 250329A: SVOM/COLIBRÍ (F-GFT) Detection of a Bright Optical Counterpart Candidate
  85. GRB 250327B: J-band observations with WINTER
  86. GRB 250327B: MASTER detection of OT rebrightening
  87. GRB 250327B: LCO optical counterpart detection
  88. GRB 250328A: GWAC-F50A optical upper limit
  89. GRB 250328A: SVOM detection of a burst
  90. FRB 20250316A: FTW optical observations
  91. LIGO/Virgo/KAGRA S250328ae: NED Galaxies in the 4-Update Localization Volume
  92. EP250302a: SPI-ACS/INTEGRAL Upper Limit
  93. GRB 250327B: CrAO and SAO RAS Optical Observations
  94. GRB 250327B: OHP/T193 spectroscopic observations and redshift confirmation
  95. GRB 250327B: further optical observations by LCOGT
  96. EP250315a: Pan-STARRS r and i-band imaging and photometry
  97. GRB 250327b: Liverpool Telescope optical observations
  98. GRB 250322A: GRANDMA/TNOT optical upper limits
  99. LIGO/Virgo/KAGRA S250328ae: Updated Sky localization
  100. GRB 250327A: SVOM/VT upper limits on the XRT position

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