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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"

19664 results found.

  1. GRB 260924A: CrAO ZTSh optical observations
  2. GRB 261017A: SVOM/GRM observation
  3. GRB 261017A: SAO RAS optical upper limit
  4. GRB 261017A: COLIBRÍ optical upper limit
  5. Konus-Wind detection of GRB 261017A
  6. GRB 261017A: Possible Swift/UVOT Detection
  7. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  8. GRB 261017A: R-band upper limit with the 1.3-m DFOT
  9. GRB 261017A: Swift-BAT refined analysis
  10. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  11. GRB 261017A : MITSuME Akeno optical upper limits
  12. GRB 261017A: Swift-XRT refined Analysis
  13. GRB 261017A: Nanshan/NEXT optical upper limit
  14. GRB 261017A: Enhanced Swift-XRT position
  15. GRB 261017A: Fermi GBM Observation
  16. GRB 261017A: Swift detection of a burst
  17. GRB 261011A: 1.3m DFOT optical upper limit
  18. GRB 261010A: Pan-STARRS z-band imaging and upper limit
  19. GRB 261010A: LBT tentative near-infrared detection
  20. GRB 261010A: Glowbug gamma-ray detection
  21. GRB 261011A: Later-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  22. GRID detection of GRB 261010A
  23. GRB 261011A: GECAM-B observation
  24. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  25. GRB 261010A: Swift-XRT refined Analysis
  26. GRB 261011A: Swift-XRT refined Analysis
  27. GRB 261011A: Enhanced Swift-XRT position
  28. GRB 261011A: 10.4m GTC spectroscopic redshift (z = 2.407)
  29. GRB 261011A: Swift-BAT refined analysis
  30. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  31. GRB 261011A: REM optical/NIR observations
  32. Konus-Wind detection of GRB 261010A
  33. Konus-Wind detection of GRB 261011A
  34. GRB 261011A: SOAR optical afterglow observations at ~17 hours
  35. GRB 261010A: Swift-BAT refined analysis
  36. GRB 261011A : MITSuME Akeno optical afterglow candidate detection
  37. GRB 261011A: Optical followup from Sichuan South Observatory
  38. GRB 261011A: GMG Optical Observation
  39. GRB 261011A: Liverpool Telescope optical observations
  40. GRB 261011A: J-band observations by the SYSU 80cm infrared telescope
  41. GRB 261010A: NOT confirmation of the optical afterglow
  42. GRB 261010A: Fermi GBM Observation
  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/VT optical observation from VHF data
  49. GRB 261011A: LCO optical observations
  50. GRB 261011A: TRT optical afterglow detection
  51. GRB 261011A: GOTO optical counterpart detection
  52. GRB 261011A: Swift detection of an unusual burst
  53. GRB 261010A: Enhanced Swift-XRT position
  54. GRB 261010A: possible optical afterglow detected with the 1.5m OSN
  55. GRB 261010A: NOT possible optical counterpart
  56. GRB 261010A: Swift detection of a burst
  57. EP261006a: Swift/XRT detection of the fading X-ray counterpart
  58. GRB 261007A: Swift-XRT afterglow detection
  59. GRB 261007A: Swift ToO observations
  60. GRB 261005B: Swift-BAT refined analysis
  61. GRB 261005B: Swift-XRT refined Analysis
  62. GRB 261005B: Swift/UVOT Upper Limits
  63. GRB 261005B: J-band upper limit with WINTER
  64. GRB 261005B: Fermi GBM Observation
  65. GRB 261005B: Enhanced Swift-XRT position
  66. GRB 261005B: Swift detection of a burst
  67. EP#01709320865: Swift-XRT observations
  68. Trigger_21915: Swift ToO observations (retracted)
  69. GRB 260924A: Swift/UVOT UV grism spectrum results
  70. GRB 260925A: Swift-BAT refined analysis
  71. Swift Trigger 1513439: consistent with noise and not astrophysical
  72. GRB 260924A: COLIBRÍ optical observations
  73. GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  74. GRB 260925A: Swift-XRT refined Analysis
  75. Swift Trigger 1513439 is probably not a GRB
  76. GRB 260925A: Swift/UVOT Upper Limits
  77. Konus-Wind detection of GRB 260924A
  78. GRB 260922A: Glowbug gamma-ray detection
  79. GRB 260925A: Enhanced Swift-XRT position
  80. GRB 260925A: COLIBRÍ optical upper limits
  81. GRB 260925A: FRAM-Auger optical limit
  82. GRB 260924A: Ondrejov D50 optical afterglow detection
  83. GRB 260924A: SVOM/GRM observation
  84. GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
  85. GRB 260925A: Swift detection of a burst
  86. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  87. GRB 260924A: Swift/UVOT Detection
  88. GRB 260924A: Swift-BAT refined analysis
  89. GRB 260924A: NuSTAR detection of prompt emission
  90. GRB 260924A: Swift/UVOT Upper Limits
  91. GRB 260924A: Swift-XRT refined Analysis
  92. Konus-Wind detection of GRB 260922A
  93. GRB 260922A: NuSTAR detection of prompt emission
  94. GRB 260921A: NuSTAR detection of prompt emission
  95. GRB 260921A: SVOM/GRM observation
  96. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  97. GRB 260924A: Fermi GRB Observation
  98. Konus-Wind detection of GRB 260921A (possible merger-origin)
  99. GRB 260924A: Fermi-LAT detection of a bright burst
  100. GRB 260924A: AstroSat CZTI detection

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