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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').
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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"

23446 results found.

  1. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  2. EP251222a: NTT/ULTRACAM optical observations
  3. GRB 251222A / EP251222b: GOTO optical counterpart detection
  4. GRB 251222A / EP251222b: LCO optical observations
  5. GRB 251222A: 1.3m DFOT optical detection
  6. GRB251221A: 7DT optical upper limits
  7. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  8. EP251222a: Einstein Probe detection of an X-ray transient
  9. GRB 251222A: PRIME near-infrared detection
  10. EP251221a: NOT optical upper limit
  11. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  12. GRB 251222A: NOT optical observations
  13. IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
  14. IPN triangulation of GRB 251220B (short)
  15. GRB 251222A: SVOM/VT optical candidate
  16. GRB 251222A: SVOM detection of a long burst
  17. EP251220a: PRIME upper limit
  18. GRB 251221A: PRIME near-infrared observation
  19. GRB 251221A: UAFO and Mondy optical upper limit
  20. GRB 251221A: Swift-XRT refined Analysis
  21. EP251221a: Einstein Probe detection of a fast X-ray transient
  22. GRB 251221A: Swift/UVOT Upper Limits
  23. GRB 251221A: Enhanced Swift-XRT position
  24. GRB 251220B: SVOM/GRM observation of a short burst
  25. EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
  26. EP 251220a: GOTO optical counterpart detection
  27. GRB 251221A: COLIBRÍ detection of the optical counterpart
  28. EP 251220a: COLIBRÍ detection of the optical counterpart
  29. GRB 251221A: Swift detection of a burst
  30. EP251220a: EP detection of a fast X-ray transient
  31. GRB 251219A: SVOM/GRM observation of a short burst
  32. GRB 251215A: Swift-XRT afterglow detection
  33. IceCube-251218A: COLIBRÍ optical upper limits
  34. GRB 251214B: VIRT Optical Upper Limit
  35. GRB 251215A: Swift/UVOT Upper LImits
  36. GRB 251202A/EP251202a: Koshka optical upper limit
  37. GRB 251214B: Mondy optical upper limit
  38. GRB 251215A: COLIBRÍ optical upper limit
  39. EP251214b: KAIT optical upper limit
  40. GRB 251215A: Swift-XRT observations
  41. EP251214a: Optical upper limit with Kinder observations
  42. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  43. GRB 251215A: Glowbug gamma-ray detection
  44. GRB 251214B: UAFO optical upper limit
  45. GRB 251214B: VLT/X-shooter observations
  46. GRB 251202A: radio detection with the VLA
  47. EP251214b : Einstein Probe detection of a fast X-ray transient
  48. EP251214b : Einstein Probe detection of a fast X-ray transient
  49. GRB 251214B: AbAO optical observations
  50. GRB 251214B: LCO detection of the optical counterpart
  51. EP251214b (EP trigger 01709250023): LCO optical limits
  52. GRB 251203B: AbAO optical observations
  53. GRB 251215A: Swift/BAT-GUANO arcminute localization of a burst
  54. GRB 251214B: Swift-XRT refined Analysis
  55. GRB 251213A: SVOM/GRM observation
  56. EP251214a: KAIT optical upper limit
  57. GRB 251214D: AstroSat CZTI detection of a long burst
  58. GRB 251214B: Swift/UVOT Detection
  59. GRB 251214B: COLIBRÍ observations of the afterglow
  60. EP251214a: EP-FXT non-detection and upper limit
  61. GRB 251214B: 1.3m DFOT optical detection
  62. GRB 251214B: Enhanced Swift-XRT position
  63. GRB 251214B: Xinglong-2.16m optical observation
  64. GRB 251214B : MASTER optical afterglow detection
  65. GRB 251214B: SVOM/C-GFT optical observations
  66. EP251214a: COLIBRÍ optical upper limit
  67. EP251214.305: COLIBRÍ optical upper limit
  68. GRB 251214B: Swift detection of a burst with an optical counterpart
  69. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  70. Fermi GRB 251214A: Global MASTER-Net observations report
  71. EP251212a: KAIT optical upper limit
  72. EP251212a : COLIBRÍ optical upper limit
  73. EP251212a: Einstein Probe detection of an X-ray transient
  74. IceCube-251210A: DDOTI Optical Upper Limit
  75. GRB 251205A: 1.3m DFOT optical upper limit
  76. GRB 251209A: AstroSat CZTI detection
  77. EP251124a: Mondy optical upper limit
  78. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  79. EP251130a: Mondy and AbAO optical observations
  80. GRB 251208A: Glowbug gamma-ray detection
  81. GRB 251208B: COLIBRÍ optical upper limits
  82. EP251118a / GRB 251118C: VLT/MUSE redshift confirmation
  83. GRB 251206A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  84. GRB 251208B: Swift-XRT afterglow detection
  85. GRB 251208D: LAST optical upper limit
  86. GRB 251208D: LCO analysis of the XRT sources
  87. GRB 251208B: GROWTH-India Telescope optical upper limits
  88. GRB 251205A: J-band detection with WINTER
  89. GRB 251208D: Swift-XRT observations
  90. GRB 251208A: SVOM/GRM observation of a short burst
  91. GRB 251208C: SVOM/GRM observation of a short burst
  92. GRB 251129A: e-MERLIN C-band observations
  93. GRB 251205A: Liverpool Telescope further optical follow-up observations
  94. GRB 251208D: LCO optical upper limits
  95. GRB 251205A : MITSuME Akeno optical afterglow candidate detection
  96. GRB 251205A: Liverpool Telescope further optical follow-up observations
  97. GRB 251205A: GROWTH-India Telescope optical observations
  98. GRB 251205A: Swift/UVOT Detection
  99. GRB 251205A: Liverpool Telescope optical follow-up observations
  100. GRB 251203C: Swift/UVOT Upper Limit

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