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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"

16319 results found.

  1. GRB 261029A: WFST optical observations
  2. GRB 261029A: ULL-ASTRO-MASTER observations with LCO 1-m telescope at Siding Spring Observatory
  3. GRB 261029A: Ondrejov D50 optical observations, possible rebrightening
  4. GRB 261029A: Liverpool Telescope observations
  5. GRB 261029A: NuSTAR detection of bright prompt emission
  6. GRB 261029A: Optical detection with 60cm Panzhihua Telescope
  7. GRB 261029A: Fermi GBM Observation
  8. GRB 261029A: FRAM-ORM and FRAM-Auger optical afterglow light curve
  9. GRB 261029A: SVOM/GRM observation of a bright burst
  10. GRB261029A: Infrared fading detected with MDM/MIRAGE
  11. GRB 261029A: SVOM/VT optical observation
  12. GRB 261029A / AT2026ahaw: r- and i-band optical follow-up with the PKU 60cm Telescope
  13. GRB 261029A: SVOM/C-GFT optical observations
  14. EP261010a: Xinglong optical follow-up
  15. GRB 261029A: EP-FXT follow-up observation
  16. GRB 261029A: Fermi-LAT detection
  17. GRB 261029A: LCO optical observations (correction to GCN 46082)
  18. GRB 261029A: SVOM/COLIBRÍ (FM-GFT) optical observations
  19. GRB 261029A: LCO optical observations
  20. GRB 261029A: NOT imaging and spectroscopic redshift z = 3.27
  21. GRB261029A: Early infrared detection with MDM/MIRAGE
  22. GRB 261029A: KAIT optical observations
  23. GRB 261029A: TRT optical observations
  24. EP261006a / AT 2026aetp: Xinglong 2.16-m optical follow-up
  25. EP261025a: EP-FXT follow-up observations
  26. GRB 261029A: GOTO optical counterpart candidate
  27. GRB261026A: Infrared detection with MDM/MIRAGE
  28. GRB 261026A: SVOM/VT optical blue bump
  29. GRB 261026A: SAO RAS optical observations
  30. GRB 261026A: EP-FXT follow-up observation
  31. GRB 261024A: SVOM/GRM observation
  32. GRB 261026A: Upper Limit with 60cm Panzhihua Telescope
  33. GRB 261026A: OHP/T120 optical imaging
  34. GRB 261026A: Ondrejov D50 optical limit
  35. GRB 261026A: ULL-ASTRO-MASTER optical detection with LCO 40-cm telescope at Haleakalā Observatory
  36. GRB 261026A: J-band observations by the SYSU 80cm infrared telescope
  37. GRB 261026A: SVOM/VT optical observations
  38. GRB 261026A: WINTER J-band observations
  39. GRB 261019A: SVOM/GRM observation
  40. GRB 261026A: SVOM/VT optical observation from VHF data
  41. GRB 261026A: KAIT optical observations
  42. GRB 261026A: SVOM/COLIBRÍ (FM-GFT) optical observations
  43. EP261025a: J-band upper limit with WINTER
  44. EP261023a: J-band upper limit with WINTER
  45. EP 261025a: COLIBRÍ optical upper limit
  46. EP261023a: J band upper limit by SYSU 80cm infrared telescope
  47. EP261015a: VST optical observations
  48. EP261023a: Mondy optical upper limit
  49. EP261015a: MAO/AZT-22 optical observations
  50. EP261015a: VLA non-detection
  51. EP261023a: NOT optical counterpart candidate
  52. EP261015a: GSP multiband optical follow-up observations
  53. GRB 261017A: SVOM/GRM observation
  54. EP261015a: Further optical observations with the 1.3m DFOT
  55. EP261015a: AZT-20 Assy-Turgen optical observations
  56. GRB 261017A: SAO RAS optical upper limit
  57. EP261015a: Wendelstein 43 cm optical observations
  58. EP261015a: Follow-up with the 1.3m DFOT
  59. EP261015a: Terskol Zeiss-2000 optical upper limit
  60. EP261007b: Further EP-FXT follow-up observations
  61. GRB 261017A: COLIBRÍ optical upper limit
  62. EP261015a: COLIBRÍ optical observations of a rebrightening
  63. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  64. GRB 261017A: R-band upper limit with the 1.3-m DFOT
  65. EP261015b: NOT Optical Observations
  66. GRB 261017A : MITSuME Akeno optical upper limits
  67. GRB 261017A: Nanshan/NEXT optical upper limit
  68. GRB261010A: Retraction of Keck/MOSFIRE near-IR source
  69. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  70. EP261015a: refined analysis of EP-FXT observations
  71. EP261015a: J-band upper limit with WINTER
  72. EP261006a / AT 2026aetp: Optical follow-up with the 1.3-m DFOT
  73. GRB 261011A: 1.3m DFOT optical upper limit
  74. EP261015a: SVOM/VT optical observation
  75. EP261015a: COLIBRÍ optical observations
  76. GRB261010A: Keck/MOSFIRE detection of a near-IR source
  77. EP261015a: Einstein Probe detection of a fast X-ray transient
  78. EP261015a (WXT 11900947714): Possible optical counterpart from NOT and LCO
  79. GRB 261010A: ASKAP non-detection of a radio afterglow
  80. GRB 261011A: SAO RAS and AbAO optical observations
  81. GRB 261008A: SVOM/GRM observation
  82. EP261006a : MeerKAT radio observations.
  83. GRID detection of GRB 261010A
  84. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  85. GRB 261010A: a Type I-L (merger-driven) GRB candidate
  86. GRB 261011A: 10.4m GTC spectroscopic redshift (z = 2.407)
  87. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  88. GRB 261011A: REM optical/NIR observations
  89. GRB 261011A: SOAR optical afterglow observations at ~17 hours
  90. EP261006a: 10 GHz VLA observations
  91. GRB 261011A: VLT/X-shooter redshift constraints
  92. GRB 261011A : MITSuME Akeno optical afterglow candidate detection
  93. GRB 261011A: Optical followup from Sichuan South Observatory
  94. GRB 261011A: GMG Optical Observation
  95. GRB 261011A: Liverpool Telescope optical observations
  96. GRB 261011A: J-band observations by the SYSU 80cm infrared telescope
  97. GRB 261010A: NOT confirmation of the optical afterglow
  98. GRB 261011A: continued LCO optical observations
  99. GRB 261011A: GROWTH-India Telescope optical observations
  100. GRB 261011A: Luminance-band upper limit from a 28cm telescope in Chengde

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