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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"

37228 results found.

  1. GRB 261011A: 1.3m DFOT optical upper limit
  2. GRB 261010A: Pan-STARRS z-band imaging and upper limit
  3. EP241111a and EP250125a: Upper limits from SVOM/GRM Observations
  4. GRB 261010A: VLA radio observations
  5. GRB261010A: Keck/MOSFIRE detection of a near-IR source
  6. GRB 261010A: ASKAP non-detection of a radio afterglow
  7. GRB 261010A: LBT tentative near-infrared detection
  8. GRB 261011A: SAO RAS and AbAO optical observations
  9. GRB 261010A: Glowbug gamma-ray detection
  10. GRB 261008A: SVOM/GRM observation
  11. GRB 261009A: GECAM-B detection of a burst
  12. GRB 261010A: initial pulse rest-frame energetics from Konus-Wind detection
  13. GRB 261010A: a short minimum variability timescale and a distinct pulse evolution compatible with a merger origin
  14. GRB 261013A: Fermi GBM Final Real-time Localization
  15. GRB 261011A: Later-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  16. GRID detection of GRB 261010A
  17. GRB 261011A: GECAM-B observation
  18. GRB 261011B: GECAM-B observation
  19. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  20. GRB 261010A: Swift-XRT refined Analysis
  21. GRB 261011A: Swift-XRT refined Analysis
  22. GRB 261011A: Enhanced Swift-XRT position
  23. GRB 261010A: a Type I-L (merger-driven) GRB candidate
  24. GRB 261011A: 10.4m GTC spectroscopic redshift (z = 2.407)
  25. GRB 261011A: Swift-BAT refined analysis
  26. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  27. GRB 261011A: REM optical/NIR observations
  28. Konus-Wind detection of GRB 261010A
  29. Konus-Wind detection of GRB 261011A
  30. Konus-Wind detection of GRB 261007A/EP261007a
  31. GRB 261011A: SOAR optical afterglow observations at ~17 hours
  32. GRB 261011A: VLT/X-shooter redshift constraints
  33. GRB 261012A: MAXI GSC detection
  34. GRB 261010A: Swift-BAT refined analysis
  35. GRB 261011A : MITSuME Akeno optical afterglow candidate detection
  36. GRB 261011A: Optical followup from Sichuan South Observatory
  37. GRB 261011A: GMG Optical Observation
  38. GRB 261011A: Liverpool Telescope optical observations
  39. GRB 261011A: J-band observations by the SYSU 80cm infrared telescope
  40. GRB 261010A: NOT confirmation of the optical afterglow
  41. GRB 261010A: Fermi GBM Observation
  42. GRB 261011B: Fermi GBM Final Localization
  43. GRB 261011A: continued LCO optical observations
  44. GRB 261011A: GROWTH-India Telescope optical observations
  45. GRB 261011A: Luminance-band upper limit from a 28cm telescope in Chengde
  46. Swift GRB 261011A: Global MASTER-Net observations report
  47. GRB 261011A: Optical follow-up observations with Kinder
  48. GRB 261011A: SVOM/C-GFT optical observations
  49. GRB 261011A: LCO optical observations
  50. GRB 261011A: SVOM/VT optical observation from VHF data
  51. GRB 261011A: LCO optical observations
  52. GRB 261011A: TRT optical afterglow detection
  53. GRB 261011A: GOTO optical counterpart detection
  54. GRB 261011A: Swift detection of an unusual burst
  55. GRB 261011A: SVOM detection of a long bright burst
  56. GRB 261010A: Enhanced Swift-XRT position
  57. GRB 261010A: possible optical afterglow detected with the 1.5m OSN
  58. GRB 261010A: NOT possible optical counterpart
  59. GRB 261010A: Swift detection of a burst
  60. GRB 261010A: Fermi GBM Final Real-time Localization
  61. GRB 261001A: SVOM/GRM observation
  62. GRB 261009A: Fermi GBM Final Real-time Localization
  63. GRB 261008A: GECAM-B observation
  64. EP261006a: Optical follow-up observations with MATCH
  65. GRB 261007A: SVOM/ECLAIRs refined analysis
  66. GRB 261007A / EP261007a: SVOM/GWAC-F60A/B observations
  67. GRB 261007A: Glowbug gamma-ray detection
  68. GRB 261008A: Fermi GBM Final Real-time Localization
  69. GRB 261007A: NOT optical observations
  70. GRB 261007A: SVOM/GRM observation
  71. GRB 261007A / EP261007a: AstroSat CZTI detection
  72. GRB 261005A: GECAM-B observation
  73. EP261007a/GRB 261007A：Xinglong optical observation
  74. GRB 261007A/EP261007a: Optical follow-up observations with Kinder
  75. EP261006a: Optical follow-up observations with Kinder
  76. GRB 261007A / EP261007a: SVOM/VT optical observations
  77. GRB 261007A: Swift-XRT afterglow detection
  78. GRB 261007A: SVOM/COLIBRÍ (FM-GFT) optical observations
  79. GRB 261007A / EP261007a: NuSTAR detection of prompt emission
  80. GRB 261007A / EP261007a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at McDonald Observatory
  81. GRB 261007A: Autonomous identification and follow-up of the counterpart to GRB 261007A by BTSbot with ZTF and P60/SEDM
  82. GRB 261007A: GROWTH-India Telescope optical observations
  83. GRB 261007A / EP261007a: TRT optical observations
  84. GRB 261007A: Swift ToO observations
  85. GRB 261007A: SVOM/C-GFT optical observations
  86. GRB 261007A / EP261007a: LCO optical observations
  87. GRB 261007B: Fermi GBM Final Real-time Localization
  88. GRB 261005B: Swift-BAT refined analysis
  89. GRB 261007A: WINTER J-band observations
  90. GRB 261007A: Fermi GBM observation
  91. GRB 261007A / EP261007a: VLT/X-shooter spectroscopic redshift z = 2.101
  92. EP261007a/GRB 261007A: Einstein Probe detection of an X-ray transient
  93. GRB 261007A: KAIT optical counterpart candidate
  94. GRB 261007A: SVOM detection of a burst
  95. GRB 261005B: Swift-XRT refined Analysis
  96. GRB 261005A: Glowbug gamma-ray detection
  97. GRB 261005B: Swift/UVOT Upper Limits
  98. GRB 261005B: J-band upper limit with WINTER
  99. GRB 261001A: GECAM-B observation of a likely long GRB
  100. GRB 261005B: Fermi GBM Observation

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