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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"

36260 results found.

  1. GRB 250129A: Early afterglow detection by LCO.
  2. GRB 250128B: OHP/T193 optical upper limit
  3. Swift GRB 250129A: Global MASTER-Net Slowly evolving LC detection
  4. GRB 250129A: LCO optical observations
  5. GRB 250129A: NOT optical observations and redshift confirmation
  6. GRB 250129A: GOTO optical observations show brightening afterglow
  7. GRB 250129A: VLT/X-shooter redshift of z = 2.151
  8. Swift GRB 250129A: Global MASTER-Net observations report
  9. GRB 250128B: Enhanced Swift-XRT position
  10. Fermi GRB 250128B: Global MASTER-Net observations report
  11. GRB 250129A: Swift detection of a burst with an optical counterpart
  12. Swift GRB 250129A: Global MASTER-Net OT detection
  13. GRB 250128B: Swift-XRT refined Analysis
  14. GRB 250128B: Fermi GBM Observation
  15. GRB 250128B: GOTO optical upper limit
  16. Swift GRB 250128B: Global MASTER-Net observations report
  17. EP250125a: Upper limits from Swift/BAT-GUANO
  18. GRB 250128B: LCO optical observations
  19. GRB 250128B: Swift detection of a short burst
  20. GRB 250128B: Fermi GBM Final Real-time Localization
  21. GRB 250127A: Swift-XRT observations
  22. GRB 250127B: DDOTI Upper Limit on the Afterglow
  23. GRB 250127A: EP-FXT afterglow detection
  24. Fermi GRB 250128A: Global MASTER-Net observations report
  25. GRB 250128A: Fermi GBM Final Real-time Localization
  26. GRB 250117A: Fermi GBM Observation
  27. Fermi GRB 250127B: Global MASTER-Net observations report
  28. GRB 250127A: SVOM/VT upper limit
  29. GRB 250127B: Fermi GBM Final Real-time Localization
  30. IPN triangulation of GRB 250119C
  31. GRB 250127A: Swift ToO observations
  32. GRB 250127A: LCO optical upper limit
  33. GRB 241223A: cubesat Avion detection
  34. GRB 250127A: SVOM detection of a long burst
  35. GRB 250126A: CALET Gamma-Ray Burst Monitor detection
  36. EP250125A: Non-detection from Fermi-GBM Observations
  37. GRB 250126A: MAXI/GSC detection
  38. GRB 250126A: BALROG localization (Fermi Trigger 759560335 / GRB 250126208)
  39. GRB 250126A: Fermi GBM Final Real-time Localization
  40. GRB 250118A: Fermi GBM Observation
  41. GRB 250119C: Fermi GBM Observation
  42. GRB 250121A: Swift/BAT-GUANO localization skymap of a burst
  43. GRB 250121A: CALET Gamma-Ray Burst Monitor detection
  44. EP250108a: AbAO, CMO and Terskol optical upper limits
  45. Konus-Wind detection of GRB 250118B
  46. GRB 250121A: Fermi GBM Observation
  47. IPN triangulation of GRB 250118B
  48. Konus-Wind detection of GRB 250119B
  49. IPN triangulation of GRB 250119B
  50. GRB 250122A: Fermi GBM Final Real-time Localization
  51. Improved IPN triangulation of GRB 250107C
  52. GRB 250114A: Swift-BAT refined analysis
  53. GRB 250121A: INTEGRAL/SPI-ACS detection
  54. GRB 250121A: Fermi-LAT detection
  55. GRB 250119C: Swift/BAT-GUANO localization skymap of a short burst
  56. GRB 250119B: Swift/BAT-GUANO localization skymap of a long burst
  57. GRB 250121A: Fermi GBM Final Real-time Localization
  58. GRB 250118A: Swift/BAT-GUANO localization skymap of a short burst
  59. GRB 250119B: Fermi GBM Observation
  60. Konus-Wind detection of GRB 250117A
  61. IPN triangulation of GRB 250117A (short)
  62. ATCA detection of possible radio counterpart to GRB 250114A
  63. GRB 250119B: INTEGRAL/SPI-ACS detection
  64. EP 250108A: Late-time optical observation by LCO
  65. GRB 250117A: SVOM/GRM observation of a short burst
  66. GRB 250119C: Fermi GBM Final Real-time Localization
  67. GRB 250117A: Swift/BAT-GUANO localization skymap of a short burst
  68. EP250108a / SN2025kg: Gemini GMOS-S confirmation of an associated broad-lined SN Ic
  69. EP250108a/AT 2025kg: NOT spectroscopy in agreement with SN Ic-BL
  70. EP250108a / AT 2025kg: the kangaroo is hopping, evidence for optical rebrightening
  71. GRB 250117A: GECAM observation of a short burst
  72. GRB 250119B: BALROG localization (Fermi Trigger 758968026 / GRB 250119352)
  73. GRB 250119B: Fermi GBM Final Real-time Localization
  74. GRB 250119A: Fermi GBM Final Real-time Localization
  75. GRB 250118A: Fermi GBM Final Real-time Localization
  76. EP250108a / AT2025kg: VLA radio upper limit
  77. Fermi Gamma-ray Burst Monitor trigger 758829338/250117747 is not a GRB
  78. Konus-Wind detection of GRB 250116A
  79. GRB 250116A: GECAM-B detection of a long burst
  80. GRB 241217A / EP241217B: radio detection with the VLA
  81. GRB 250116A: INTEGRAL/SPI-ACS and PICsIT detection
  82. Swift Trigger 1282245 is not a GRB
  83. GRB 250116A: Fermi-LAT detection
  84. GRB 250116A: Fermi GBM Observation of an Extremely Interesting Burst
  85. GRB 250114B: Swift-XRT afterglow detection
  86. GRB 250114B: SVOM/VT upper limit
  87. Fermi Gamma-ray Burst Monitor trigger 758659047/250115776 is not a GRB
  88. GRB 250101A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations and rebrightening.
  89. Konus-Wind detection of GRB 250113A
  90. IPN triangulation of GRB 250113A
  91. GRB 250114B: Liverpool Telescope optical upper limit
  92. GRB 250114B : MITSuME Akeno optical afterglow candidate detection
  93. GRB 250114B: Swift-XRT observations
  94. GRB 250114A: LCO optical counterpart detection.
  95. GRB 250114B: OHP/T193 optical upper limit
  96. GRB 250114A: GRANDMA/TAROT optical afterglow detection
  97. GRB 250114A: Swift-XRT refined Analysis
  98. GRB 250114A: LCOGT optical afterglow i-band detection
  99. GRB 250114B : GIT optical upper limit
  100. GRB 250114B: Swift ToO observations

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