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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"

28203 results found.

  1. EP261015b: NOT Optical Observations
  2. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  3. EP261015c: refined analysis of the EP-FXT observation favors a stellar flare interpretation
  4. GRB 261017A : MITSuME Akeno optical upper limits
  5. GRB 261017A: Swift-XRT refined Analysis
  6. GRB 261017A: Nanshan/NEXT optical upper limit
  7. GRB 261017A: Enhanced Swift-XRT position
  8. GRB 261017A: Fermi GBM Observation
  9. GRB 261017A: Swift detection of a burst
  10. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  11. EP261015b: Refined analysis of EP-FXT observations
  12. EP261015b: J-band upper limit by the SYSU 80cm infrared telescope
  13. EP261015a: refined analysis of EP-FXT observations
  14. EP261015c: J-band upper limit with WINTER
  15. EP261015a: J-band upper limit with WINTER
  16. EP261006a / AT 2026aetp: Optical follow-up with the 1.3-m DFOT
  17. GRB 261011A: 1.3m DFOT optical upper limit
  18. GRB 261010A: Pan-STARRS z-band imaging and upper limit
  19. EP261015a: SVOM/VT optical observation
  20. GRB 261010A: VLA radio observations
  21. EP261015a: COLIBRÍ optical observations
  22. EP261015c: Einstein Probe detection of a fast X-ray transient
  23. EP261015b: Einstein Probe detection of an X-ray transient
  24. EP261015a: Einstein Probe detection of a fast X-ray transient
  25. EP261015a (WXT 11900947714): Possible optical counterpart from NOT and LCO
  26. GRB 261010A: LBT tentative near-infrared detection
  27. GRB 261011A: SAO RAS and AbAO optical observations
  28. GRB 261010A: Glowbug gamma-ray detection
  29. GRB 261008A: SVOM/GRM observation
  30. GRB 261009A: GECAM-B detection of a burst
  31. EP261006a : MeerKAT radio observations.
  32. IceCube-261012A: Upper limits from a search for additional neutrino events in IceCube
  33. GRB 261010A: a short minimum variability timescale and a distinct pulse evolution compatible with a merger origin
  34. Fermi-LAT Gamma-ray Observations of IceCube-261012A
  35. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  36. GRB 261010A: Swift-XRT refined Analysis
  37. GRB 261011A: Swift-XRT refined Analysis
  38. GRB 261011A: Enhanced Swift-XRT position
  39. GRB 261010A: a Type I-L (merger-driven) GRB candidate
  40. GRB 261011A: Swift-BAT refined analysis
  41. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  42. MAXI GRB261012.23: Global MASTER-Net observations report
  43. GRB 261011A: REM optical/NIR observations
  44. GRB 261011A: SOAR optical afterglow observations at ~17 hours
  45. EP261006a: 10 GHz VLA observations
  46. GRB 261011A: VLT/X-shooter redshift constraints
  47. GRB 261012A: MAXI GSC detection
  48. GRB 261010A: Swift-BAT refined analysis
  49. GRB 261011A : MITSuME Akeno optical afterglow candidate detection
  50. GRB 261011A: Optical followup from Sichuan South Observatory
  51. GRB 261011A: GMG Optical Observation
  52. GRB 261011A: Liverpool Telescope optical observations
  53. GRB 261011A: J-band observations by the SYSU 80cm infrared telescope
  54. GRB 261010A: NOT confirmation of the optical afterglow
  55. GRB 261010A: Fermi GBM Observation
  56. GRB 261011A: continued LCO optical observations
  57. EP261007b: Global MASTER-Net observations report
  58. GRB 261011A: GROWTH-India Telescope optical observations
  59. GRB 261011A: Luminance-band upper limit from a 28cm telescope in Chengde
  60. Swift GRB 261011A: Global MASTER-Net observations report
  61. GRB 261011A: Optical follow-up observations with Kinder
  62. GRB 261011A: SVOM/C-GFT optical observations
  63. EP261007b: Second EP-FXT follow-up observation and a possible X-ray counterpart to the optical transient
  64. GRB 261011A: LCO optical observations
  65. GRB 261011A: SVOM/VT optical observation from VHF data
  66. GRB 261011A: LCO optical observations
  67. GRB 261011A: TRT optical afterglow detection
  68. GRB 261011A: Swift detection of an unusual burst
  69. GRB 261011A: SVOM detection of a long bright burst
  70. GRB 261010A: Enhanced Swift-XRT position
  71. EP261010a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  72. EP261006a / AT 2026aetp: Luminance-band optical follow-up with small-aperture telescopes
  73. GRB 261010A: Swift detection of a burst
  74. EP261006a: Kilonova-Catcher optical follow-up and detection
  75. EP261006a / AT 2026aetp: Multiband optical follow-up with the PKU 60cm Telescope
  76. EP261010a: SVOM/VT optical upper limits
  77. EP261006a: Liverpool Telescope optical follow-up
  78. EP261010a: NOT optical upper limits
  79. EP261010a: Global MASTER-Net observations report
  80. EP261010a Einstein Probe detection of an X-ray transient
  81. GRB261007A: Lesedi optical afterglow detection
  82. EP261006a: Xinglong 2.16m/BFOSC optical follow-up observations
  83. EP261007b: SVOM/ECLAIRs Upper Limit
  84. EP261006a: Optical follow-up observations with MATCH
  85. EP261007b: J-band upper limit by SYSU 80cm infrared telescope
  86. EP261007b: Refined analysis of the EP-WXT and autonomous EP-FXT observations
  87. GRB 261007A: SVOM/ECLAIRs refined analysis
  88. GRB 261007A / EP261007a: SVOM/GWAC-F60A/B observations
  89. GRB 261007A: Glowbug gamma-ray detection
  90. EP261007b: NOT optical observations, variable source outside the FXT region
  91. EP261007b: SVOM/C-GFT optical upper limits
  92. EP261007b: J-band upper limit with WINTER
  93. The EP-WXT trigger 01709321008/EP261007b：Xinglong optical upper limit
  94. EP261006a: Swift/XRT detection of the fading X-ray counterpart
  95. EP261007a/GRB 261007A：Xinglong optical observation
  96. GRB 261007A/EP261007a: Optical follow-up observations with Kinder
  97. EP261006a: Optical follow-up observations with Kinder
  98. EP261006a: Liverpool Telescope optical observations
  99. EP261006a: Early Optical Observations by WFST
  100. GRB 261007A / EP261007a: SVOM/VT optical observations

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