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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"

36226 results found.

  1. GRB 261108A: LCO optical upper limits
  2. GRB 261108A: FRAM-Auger optical limits
  3. GRB 261103A: SVOM/VT optical upper limits
  4. GRB 261108A: SVOM detection of a burst
  5. GRB 261108A: Fermi GBM Final Real-time Localization
  6. GRB 261029C: SVOM/GRM detection of a short burst
  7. GRB 261103A: SVOM/ECLAIRs refined analysis
  8. Konus-Wind detection of GRB 261024D
  9. Konus-Wind detection of GRB 261029C (short / bright)
  10. GRB 261104A：EP-FXT follow-up observation
  11. GRB 261104A: DECam Detection of an Optical Counterpart Candidate
  12. GRB 261104A: SVOM/ECLAIRs refined analysis
  13. GRB 261104A: SVOM/VT optical upper limits
  14. IPN triangulation of GRB 261029C (short / bright)
  15. IPN triangulation of GRB 261025B (short)
  16. GRB 261103A: SVOM/C-GFT optical upper limit
  17. IPN triangulation of GRB 261024A
  18. GRB 261104A: LCO optical upper limits
  19. GRB 261104A: SVOM detection of burst
  20. GRB 260924A: CrAO ZTSh optical observations
  21. GRB 261029A : MITSuME Akeno optical afterglow detection
  22. GRB 261030C: AstroSat CZTI detection
  23. GRB 261029A: VST/OmegaCAM detection of the optical afterglow at 3 days
  24. GRB 261029A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation
  25. GRB 261103A: LCO optical upper limits
  26. GRB 261103A: SVOM/ECLAIRs detection of a burst through on-ground search
  27. Konus-Wind detection of GRB 261029A
  28. GRB 261029A: SAO RAS optical observations
  29. EP261015a/SN 2026ahoa: VLT/FORS2 discovery of a pre-peak type Ic-BL supernova at a tentative spectroscopic redshift z=0.31
  30. GRB 261102A: Fermi GBM Detection
  31. GRB 261029C: AstroSat CZTI detection of a short burst
  32. GRB 261102A: Fermi GBM Final Real-time Localization
  33. GRB 261101B: BALROG localization (Fermi Trigger 815240277 / GRB 261101651)
  34. GRB 261101B: Fermi GBM Final Real-time Localization
  35. GRB 261101A: Fermi GBM Final Real-time Localization
  36. GRB 261030A: Fermi GBM Detection
  37. Fermi GRB 261030B: Global MASTER-Net observations report
  38. GRB 261030B: Fermi GBM Final Real-time Localization
  39. GRB 261029A: SVOM/ECLAIRs refined analysis
  40. The EP-WXT trigger 01709321980: KAIT confirmation of a stellar flare
  41. GRB 261030A: BALROG localization (Fermi Trigger 815070447 / GRB 261030686)
  42. GRB 261030A: Fermi GBM Final Real-time Localization
  43. GRB 261029A / AT 2026ahaw: Optical upper limits from the PKU 60cm Telescope
  44. GRB 261029A: Glowbug gamma-ray detection
  45. GRB 261024D: SVOM/GRM observation
  46. GRB 261026A: Mondy, SAO RAS and Terskol optical observations
  47. GRB 261029A : SVOM/GWAC-F60 observations
  48. GRB 261029A: GECAM-B detection of a bright burst
  49. GRB 261029A: WFST optical observations
  50. GRB 261029A: ULL-ASTRO-MASTER observations with LCO 1-m telescope at Siding Spring Observatory
  51. GRB 261029A: Ondrejov D50 optical observations, possible rebrightening
  52. GRB 261029A: Liverpool Telescope observations
  53. GRB 261029A: NuSTAR detection of bright prompt emission
  54. GRB 261029A: Optical detection with 60cm Panzhihua Telescope
  55. GRB 261029A: Fermi GBM Observation
  56. GRB 261029A: FRAM-ORM and FRAM-Auger optical afterglow light curve
  57. GRB 261029A: SVOM/GRM observation of a bright burst
  58. GRB 261029A: CALET Gamma-Ray Burst Monitor detection
  59. IPN triangulation of GRB 261024D
  60. GRB261029A: Infrared fading detected with MDM/MIRAGE
  61. GRB 261029A: SVOM/VT optical observation
  62. GRB 261029B : AstroSat CZTI detection
  63. GRB 261029A / AT2026ahaw: r- and i-band optical follow-up with the PKU 60cm Telescope
  64. GRB 261029A : AstroSat CZTI detection
  65. GRB 261029A: SVOM/C-GFT optical observations
  66. GRB 261029A: EP-FXT follow-up observation
  67. GRB 261029A: Fermi-LAT detection
  68. GRB 261029A: LCO optical observations (correction to GCN 46082)
  69. GRB 261029A: SVOM/COLIBRÍ (FM-GFT) optical observations
  70. GRB 261029A: LCO optical observations
  71. GRB 261029A: NOT imaging and spectroscopic redshift z = 3.27
  72. GRB261029A: Early infrared detection with MDM/MIRAGE
  73. GRB 261029A: KAIT optical observations
  74. GRB 261029A: TRT optical observations
  75. GRB 261029B: Fermi GBM Final Real-time Localization
  76. GRB 261028B / MAXI J1609-487: MAXI GSC detection
  77. GRB 261029A: GOTO optical counterpart candidate
  78. GRB 261029A: SVOM detection of a burst
  79. GRB 261029A: Fermi GBM Final Real-time Localization
  80. GRB 261021A: Glowbug gamma-ray detection
  81. GRB 261028A: Fermi GBM Final Localization
  82. GRB 261026A: SVOM/ECLAIRs refined analysis
  83. GRB 261024C: GECAM-B observation
  84. GRB 261026B: AstroSat CZTI detection
  85. GRB 261024D: Insight-HXMT/HE detection
  86. GRB261026A: Infrared detection with MDM/MIRAGE
  87. GRB 261026A: SVOM/VT optical blue bump
  88. GRB 261026A: SAO RAS optical observations
  89. GRB 261024D: GECAM-B observation
  90. GRB 261026A: EP-FXT follow-up observation
  91. GRB 261024A: SVOM/GRM observation
  92. GRB 261026A: Upper Limit with 60cm Panzhihua Telescope
  93. GRB 261026A: OHP/T120 optical imaging
  94. GRB 261024D: Glowbug gamma-ray detection
  95. GRB 261026B: NuSTAR detection of prompt emission
  96. GRB 261024D: NuSTAR detection of prompt emission
  97. GRB 261024C: NuSTAR detection of prompt emission
  98. GRB 261026A: Ondrejov D50 optical limit
  99. GRB 261026A: ULL-ASTRO-MASTER optical detection with LCO 40-cm telescope at Haleakalā Observatory
  100. GRB 261026A: J-band observations by the SYSU 80cm infrared telescope

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