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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"

45803 results found.

  1. EP250108a / AT 2025kg: SAO RAS optical observations
  2. EP241021a: SMA radio observation
  3. GRB 250113A: SVOM/GRM observation of a long burst
  4. GRB 250107A: VZLUSAT-2 detection
  5. EP250109b: optical upper limits with the Liverpool Telescope
  6. GRB 250109A / EP250109a: GRBAlpha detection
  7. GRB 250107D: GRBAlpha detection
  8. GRB 250106A: Swift-XRT afterglow detection
  9. Fermi trigger No 758442826: Global MASTER-Net observations report
  10. EP250111a: KAIT optical observations
  11. GRB 250109A / EP250109a: Mephisto optical upper limits
  12. EP250108a: Mephisto detection
  13. EP250111a: Mondy optical observation
  14. EP250108a / AT 2025kg: LCO optical observations
  15. EP250111a: Global MASTER-Net observations report
  16. EP250111a: Swift/XRT detection and fading
  17. EP250108a / AT 2025kg: Swift UVOT detections
  18. EP250108a / AT 2025kg (the "kangaroo”): VLT/X-shooter spectroscopic redshift z = 0.176 and LFBOT classification
  19. EP250108a: optical follow-up observations with the Liverpool Telescope
  20. EP250111a: NOT likely optical counterpart
  21. EP250111a: a new X-ray transient detected by Einstein Probe
  22. EP250109a/GRB 250109A:SVOM/VT optical counterpart
  23. GRB 250101B: Fermi GBM Observation
  24. EP250108a: further NOT optical observations
  25. GRB 250109A / EP250109a: Terskol (INASAN) and SAO RAS observations
  26. GRB 250109A / EP250109A: Swift/BAT-GUANO localization skymap of a burst
  27. GRB 250109A / EP250109a: Swift detection of the X-ray afterglow
  28. GRB 250108A: Swift/XRT afterglow fading
  29. GRB 250107D: CALET Gamma-Ray Burst Monitor detection
  30. GRB 250107C: CALET Gamma-Ray Burst Monitor detection
  31. Konus-Wind detection of GRB 250107C
  32. LIGO/Virgo/KAGRA S250109bi: Updated Sky localization
  33. LIGO/Virgo/KAGRA S250109f: Updated Sky localization
  34. LIGO/Virgo/KAGRA S250108eo: Updated Sky localization
  35. EP-WXT trigger EP250108a：Xinglong optical follow-up observations
  36. GRB 250101A: CMO RC-500 optical observations
  37. EP250109a / GRB 250109A: refined EP-WXT analysis and EP-FXT follow-up observation
  38. EP250108a: EP-FXT follow-up observation
  39. GRB 250109A: Fermi GBM Observation
  40. The EP-WXT trigger 01709130111 is likely a flaring star
  41. EP250108a: NOT optical observations
  42. EP-WXT trigger EP250109a：Xinglong optical follow-up observations
  43. GRB 250109a: GMG Optical Upper Limit
  44. EP250109a: Swift/UVOT non-detection
  45. Konus-Wind detection of GRB 250107D (short/hard)
  46. IPN triangulation of GRB 250107D (short/hard)
  47. IPN triangulation of GRB 250107C
  48. EP250108a: Liverpool Telescope likely optical counterpart
  49. GRB 250108B: Gemini-North likely redshift z = 2.197
  50. GRB 250108B: Swift-BAT refined analysis
  51. GRB 250108B: 1.3m DFOT upper limit
  52. GRB 250108B: REM optical/NIR upper limits
  53. GRB 250109A /EP250109a: Fermi GBM Final Localization
  54. EP250109a: SVOM/VT optical candidate
  55. EP250109a: Global MASTER-Net observations report
  56. GRB 250107C: SVOM/GRM observation
  57. GRB 250101A: Terskol K-800 optical observations
  58. EP250109a: GOTO optical upper limits
  59. EP250109a: Swift/XRT non-detection
  60. GRB 250108A: Swift/UVOT Upper Limits
  61. EP250108a: Global MASTER-Net observations report
  62. EP250109a: EP-WXT detection of an X-ray transient
  63. LIGO/Virgo/KAGRA S250109bi: Identification of a GW compact binary merger candidate
  64. GRB 250108A: NOT optical upper limit
  65. EP250108a: EP-WXT detection of an X-ray transient
  66. LIGO/Virgo/KAGRA S250109f: Identification of a GW compact binary merger candidate
  67. GRB 250108B: Swift-XRT refined Analysis
  68. Swift GRB 250108B: Global MASTER-Net observations report
  69. Fermi Gamma-ray Burst Monitor trigger 758061038/250108855 is not a GRB
  70. LIGO/Virgo/KAGRA S250108ha: Retraction of GW compact binary merger candidate
  71. GRB 250108B: Gemini-North Candidate Optical Afterglow Detection
  72. GRB 250103A: 1.6m Mephisto optical observations
  73. GRB 250108A: Swift-XRT afterglow detection
  74. GRB 250108A:SVOM/VT optical candidate
  75. LIGO/Virgo/KAGRA S250108eo: Identification of a GW compact binary merger candidate
  76. GRB 250108B: Swift/UVOT Upper Limits
  77. GRB 250103A: Swift-XRT afterglow detection
  78. GRB 250108B: Enhanced Swift-XRT position
  79. GRB 250108B: Swift detection of a burst
  80. GRB 250108A: Swift ToO observations
  81. GRB 250108A: SVOM detection of a soft long burst
  82. GRB 250107A: Fermi GBM Observation
  83. GRB 241228B: Fermi-LAT detection
  84. Fermi GRB 250107B: Global MASTER-Net observations report
  85. GRB 250107A: Swift ToO observations
  86. GRB 250107A: Swift/BAT-GUANO arcminute localization of a burst
  87. GRB 250107B: Fermi GBM Final Real-time Localization
  88. GRB 250106A: SVOM/VT 2nd optical deep observation
  89. GRB 250101A: J band upper limit by SYSU 80cm telescope
  90. GRB 250107A: Fermi GBM Final Real-time Localization
  91. EPWXT01709129925: Xinglong optical observations
  92. GRB 250106A: NOT optical observations
  93. LIGO/Virgo/KAGRA S250104v: Updated Sky localization
  94. GRB 250103B: REM optical/NIR upper limits
  95. GRB 250101A: REM optical/NIR counterpart detection
  96. GRB 250106A: Swift-XRT observations
  97. GRB 250106A: SVOM/VT optical candidate
  98. GRB 250106A: Swift ToO observations
  99. The EP-WXT trigger 01709129925 is likely a flaring star
  100. GRB 250106A: SVOM detection of a long burst

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