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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"

18364 results found.

  1. EP251230a / GRB 251230A: Einstein Probe detection of an X-ray transient
  2. LIGO/Virgo/KAGRA S251112cm: Candidates from the NSF-DOE Vera C. Rubin Observatory
  3. The EP-WXT trigger 01709250693/GRB 251230A: Las Cumbres detection of the optical counterpart
  4. EP251229a: Einstein Probe detection of an X-ray transient
  5. GRB 251230A: Swift detection of a burst with a bright optical counterpart
  6. GRB 251222A/EP251222b: 1.6m Mephisto optical followup
  7. The EP-WXT trigger 01709250662 is likely a flaring star
  8. GRB 251226A: SVOM/GRM observation
  9. The EP-WXT trigger 01709250617 is likely a flaring star
  10. GRB 251222A/EP251222b: Optical detection with Kinder observations
  11. EP251222a: Optical upper limit with Kinder observations
  12. GRB 251205A: Kilonova-Catcher optical afterglow detection
  13. GRB 251222A: AbAO optical observations
  14. GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
  15. GRB 251222A: ZTSH BVRI optical observations
  16. GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations
  17. GRB 251222A: Continued 1.3m DFOT optical observation
  18. EP251220a: 3.6m DOT optical afterglow detection
  19. EP251220a: CrAO ZTSh optical observations
  20. EP251221a: PRIME upper limit
  21. EP251221a: Liverpool Telescope upper limits
  22. EP251222a: refined analysis of the EP-WXT and EP-FXT observations
  23. EP251222b/GRB 251222A: refined analysis of the EP-WXT and EP-FXT observations
  24. GRB 251222A: Swift-XRT afterglow detection
  25. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  26. EP251222a: NTT/ULTRACAM optical observations
  27. GRB 251222A / EP251222b: GOTO optical counterpart detection
  28. GRB 251222A / EP251222b: LCO optical observations
  29. GRB 251222A: 1.3m DFOT optical detection
  30. GRB251221A: 7DT optical upper limits
  31. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  32. EP251222a: Einstein Probe detection of an X-ray transient
  33. The EP-WXT trigger 01709250397 is likely a flaring star
  34. GRB 251222A: PRIME near-infrared detection
  35. EP251221a: NOT optical upper limit
  36. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  37. IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
  38. IPN triangulation of GRB 251220B (short)
  39. GRB 251222A: SVOM/VT optical candidate
  40. GRB 251222A: SVOM detection of a long burst
  41. EP251220a: PRIME upper limit
  42. GRB 251221A: PRIME near-infrared observation
  43. GRB 251221A: UAFO and Mondy optical upper limit
  44. EP251221a: Einstein Probe detection of a fast X-ray transient
  45. GRB 251221A: Swift/UVOT Upper Limits
  46. GRB 251221A: Enhanced Swift-XRT position
  47. EP251220a: EP-FXT follow-up observation
  48. GRB 251220B: SVOM/GRM observation of a short burst
  49. EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
  50. EP 251220a: GOTO optical counterpart detection
  51. GRB 251221A: COLIBRÍ detection of the optical counterpart
  52. EP 251220a: COLIBRÍ detection of the optical counterpart
  53. GRB 251221A: Swift detection of a burst
  54. EP251220a: EP detection of a fast X-ray transient
  55. GRB 251219A: SVOM/GRM observation of a short burst
  56. GRB 251215A: Swift-XRT afterglow detection
  57. IceCube-251218A: COLIBRÍ optical upper limits
  58. GRB 251214B: VIRT Optical Upper Limit
  59. GRB 251215A: Swift/UVOT Upper LImits
  60. GRB 251202A/EP251202a: Koshka optical upper limit
  61. GRB 251214B: Mondy optical upper limit
  62. GRB 251215A: COLIBRÍ optical upper limit
  63. EP251214b: KAIT optical upper limit
  64. EP251214a: Optical upper limit with Kinder observations
  65. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  66. GRB 251214B: UAFO optical upper limit
  67. GRB 251214B: VLT/X-shooter observations
  68. GRB 251202A: radio detection with the VLA
  69. EP251214b : Einstein Probe detection of a fast X-ray transient
  70. EP251214b : Einstein Probe detection of a fast X-ray transient
  71. GRB 251214B: AbAO optical observations
  72. GRB 251214B: LCO detection of the optical counterpart
  73. EP251214b (EP trigger 01709250023): LCO optical limits
  74. GRB 251203B: AbAO optical observations
  75. GRB 251213A: SVOM/GRM observation
  76. EP251214a: KAIT optical upper limit
  77. GRB 251213A: AstroSat CZTI detection
  78. GRB 251214B: Swift/UVOT Detection
  79. GRB 251214B: COLIBRÍ observations of the afterglow
  80. EP251214a: EP-FXT non-detection and upper limit
  81. GRB 251214B: 1.3m DFOT optical detection
  82. GRB 251214B: Enhanced Swift-XRT position
  83. GRB 251214B: Xinglong-2.16m optical observation
  84. GRB 251214B: SVOM/C-GFT optical observations
  85. EP251214a: COLIBRÍ optical upper limit
  86. EP251214.305: COLIBRÍ optical upper limit
  87. GRB 251214B: Swift detection of a burst with an optical counterpart
  88. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  89. EP251212a: KAIT optical upper limit
  90. EP251212a / GRB 251212A: AstroSat CZTI detection
  91. EP251212a: EP-FXT follow-up observation
  92. EP251212a : COLIBRÍ optical upper limit
  93. EP251212a: Einstein Probe detection of an X-ray transient
  94. IceCube-251210A: DDOTI Optical Upper Limit
  95. GRB 251209A: Fermi GBM observation
  96. GRB 251205A: 1.3m DFOT optical upper limit
  97. EP251124a: Mondy optical upper limit
  98. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  99. EP251130a: Mondy and AbAO optical observations
  100. GRB 251208B: COLIBRÍ optical upper limits

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