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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.

Advanced Search Examples (click to copy):

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

19662 results found.

  1. Improved IPN triangulation of GRB 250107C
  2. GRB 250114A: Swift-BAT refined analysis
  3. LIGO/Virgo S250119cv: Swift XRT observations, 5 X-ray sources
  4. GRB 250119C: Swift/BAT-GUANO localization skymap of a short burst
  5. GRB 250119B: Swift/BAT-GUANO localization skymap of a long burst
  6. GRB 250118A: Swift/BAT-GUANO localization skymap of a short burst
  7. Konus-Wind detection of GRB 250117A
  8. IPN triangulation of GRB 250117A (short)
  9. GRB 250117A: SVOM/GRM observation of a short burst
  10. GRB 250117A: Swift/BAT-GUANO localization skymap of a short burst
  11. Swift Trigger 1282245 is not a GRB
  12. GRB 250114B: Swift-XRT afterglow detection
  13. GRB 250101A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations and rebrightening.
  14. IPN triangulation of GRB 250113A
  15. GRB 250114B: Swift-XRT observations
  16. GRB 250114A: LCO optical counterpart detection.
  17. GRB 250114A: GRANDMA/TAROT optical afterglow detection
  18. GRB 250114A: Swift-XRT refined Analysis
  19. GRB 250114A: LCOGT optical afterglow i-band detection
  20. GRB 250114B: Swift ToO observations
  21. EP250111a: SAO RAS optical upper limit
  22. GRB 250114A: Enhanced Swift-XRT position
  23. GRB 250114A: REM detection of the optical and NIR counterpart
  24. Swift GRB250114A: Global MASTER-Net OT detection
  25. GRB 250114A: LCO optical observations
  26. GRB 250114A: TRT optical observations
  27. Swift GRB 250114A: Global MASTER-Net observations report
  28. GRB 250114A: Swift detection of a burst with an optical counterpart
  29. GRB 250107A: VZLUSAT-2 detection
  30. GRB 250109A / EP250109a: GRBAlpha detection
  31. GRB 250106A: Swift-XRT afterglow detection
  32. GRB 250109A / EP250109a: Mephisto optical upper limits
  33. EP250111a: Swift/XRT detection and fading
  34. EP250108a / AT 2025kg: Swift UVOT detections
  35. GRB 250109A / EP250109A: Swift/BAT-GUANO localization skymap of a burst
  36. GRB 250109A / EP250109a: Swift detection of the X-ray afterglow
  37. GRB 250108A: Swift/XRT afterglow fading
  38. EP250109a / GRB 250109A: refined EP-WXT analysis and EP-FXT follow-up observation
  39. EP250109a: Swift/UVOT non-detection
  40. IPN triangulation of GRB 250107D (short/hard)
  41. IPN triangulation of GRB 250107C
  42. GRB 250108B: Swift-BAT refined analysis
  43. GRB 250108B: 1.3m DFOT upper limit
  44. GRB 250108B: REM optical/NIR upper limits
  45. EP250109a: GOTO optical upper limits
  46. EP250109a: Swift/XRT non-detection
  47. GRB 250108A: Swift/UVOT Upper Limits
  48. GRB 250108A: NOT optical upper limit
  49. GRB 250108B: Swift-XRT refined Analysis
  50. Swift GRB 250108B: Global MASTER-Net observations report
  51. GRB 250108A: Swift-XRT afterglow detection
  52. GRB 250108B: Swift/UVOT Upper Limits
  53. GRB 250103A: Swift-XRT afterglow detection
  54. GRB 250108B: Enhanced Swift-XRT position
  55. GRB 250108B: Swift detection of a burst
  56. GRB 250108A: Swift ToO observations
  57. GRB 250107A: Fermi GBM Observation
  58. GRB 241228B: Fermi-LAT detection
  59. GRB 250107A: Swift ToO observations
  60. GRB 250107A: Swift/BAT-GUANO arcminute localization of a burst
  61. GRB 250106A: NOT optical observations
  62. GRB 250103B: REM optical/NIR upper limits
  63. GRB 250101A: REM optical/NIR counterpart detection
  64. GRB 250106A: Swift-XRT observations
  65. GRB 250106A: Swift ToO observations
  66. GRB 241229A: SVOM/VT optical upperlimit
  67. GRB 250103B: Swift-XRT refined Analysis
  68. GRB 250103B: LCO/1m optical afterglow candidate detection
  69. GRB 250103A: Swift-XRT observations
  70. GRB 250101A: 1.3m DFOT optical afterglow detection
  71. GRB 241229A: 1.3m DFOT upper limit
  72. GRB 241228A: 1.3m DFOT upper limit
  73. GRB 250103B：SVOM/VT optical counterpart
  74. GRB 250101A: further LCOGT optical afterglow observations
  75. GRB 250103B: LCOGT Optical Upper Limit
  76. Swift GRB 250103B: Global MASTER-Net observations report
  77. GRB 250103A: Swift ToO observations
  78. GRB 250101a: Liverpool Telescope optical follow-up
  79. GRB 250103B: SVOM detection of a long burst
  80. GRB 250103B: Swift detection of a burst
  81. LIGO/Virgo/KAGRA S241230bd: Upper limits from Swift/BAT-GUANO
  82. GRB 250101A: Swift-BAT refined analysis
  83. GRB 250101A: further SAO RAS optical observations
  84. GRB 250101A: LCO optical counterpart detection
  85. GRB 250101A: GMG spectroscopic redshift at z ~ 2.481
  86. GRB 250101A: Swift/UVOT Detection
  87. GRB 250101A: 1.6m Mephisto multi-band optical followup
  88. GRB 250101A: Swift-XRT refined Analysis
  89. GRB 250101A: Montarrenti Observatory optical observations and rebrightening
  90. GRB 250101A: LCOGT optical afterglow detection
  91. GRB 250101A: OASDG optical observations
  92. GRB 250101A: BOOTES-4/MET optical afterglow detection
  93. GRB 250101A: SAO RAS optical observations
  94. GRB 250101A: Enhanced Swift-XRT position
  95. GRB 250101A: Xinglong-2.16m spectroscopic redshift
  96. GRB 250101A: SVOM/C-GFT early optical observations
  97. GRB 250101A: MASTER earlier OT observations with SOSS emission features
  98. GRB 250101A: Nanshan/HMT optical observations
  99. GRB 250101A : GIT optical detection
  100. GRB 250101A: Swift detection of a burst with an optical counterpart

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