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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"

26119 results found.

  1. GRB 240912A: Swift-BAT refined analysis
  2. IPN triangulation of GRB 240913C / EP 240913a
  3. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  4. GRB 240916A: Fermi GBM Observation
  5. GRB 240916A (AT 2024vlp / GOTO24fzn): VLT/X-shooter redshift
  6. GRB 240916A: Swift-XRT afterglow detection
  7. GRB 240916A: Swift ToO observations
  8. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  9. EP240913a/GRB 240913C: KAIT optical upper limit
  10. GRB 240914A: Swift-XRT observations
  11. GRB 240910A: SVOM/VT optical observations
  12. GRB 240914A: Swift ToO observations
  13. EP240913a: ESO-NTT optical observations
  14. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  15. GRB 240905E: further NOT optical observations
  16. EP240913a: EP-WXT detection of a fast X-ray transient
  17. GRB 240911A: LCO optical observations
  18. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  19. GRB 240912A: Swift/UVOT Detection
  20. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  21. GRB 240912A: SVOM/GRM observation
  22. GRB 240911A: Swift-XRT observations
  23. GRB 240912A: J-band observations with WINTER
  24. GRB 240912A: Swift-XRT refined Analysis
  25. GRB 240912A: Fermi GBM Observation
  26. Swift GRB 240912A: Global MASTER-Net observations report
  27. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  28. GRB 240911A: Tiled Swift observations
  29. GRB 240912A: NOT optical spectroscopy
  30. GRB 240912A: Enhanced Swift-XRT position
  31. GRB 240912A: Redshift from OSIRIS+/GTC
  32. GRB 240910A: Redshift from OSIRIS+/GTC
  33. GRB 240912A: Swift detection of a burst with an optical counterpart
  34. GRB 240910A: Fermi GBM Observation
  35. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  36. GRB 240910A: JinShan optical observations
  37. GRB 240910A: GOTO candidate optical counterpart
  38. EP240908a: Optical afterglow confirmation
  39. GRB 240910A: Swift ToO observations
  40. IPN triangulation of GRB 240905B (short)
  41. GRB 240905E: SVOM/VT optical observations
  42. LIGO/Virgo/KAGRA S240908bs: Upper limits from Swift/BAT-GUANO
  43. LIGO/Virgo/KAGRA S240907cg: Upper limits from Swift/BAT-GUANO
  44. EP240908a: optical afterglow candidate
  45. GRB 240905B: GOTO optical upper limits
  46. GRB 240905E: GIT optical upper limit
  47. GRB 240905B: Swift-XRT observations
  48. GRB 240905E: Gaoyazi/GOT optical upper limits
  49. GRB 240905B: Fermi-LAT detection
  50. GRB 240905B: Swift ToO observations
  51. GRB 240905E: J-band observations with WINTER
  52. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  53. GRB 240905E: AKO Optical Upper Limit
  54. GRB 240905E: SVOM/C-GFT optical upper limit
  55. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  56. GRB 240905E: NOT optical upper limits
  57. GRB 240905E: REM optical/NIR upper limits
  58. GRB 240905E: Swift-XRT refined Analysis
  59. GRB 240905E: SVOM/GRM observation
  60. GRB 240905E: LCOGT Optical Upper Limit
  61. GRB 240905E: Swift/UVOT Upper Limits
  62. GRB 240905E: SAO RAS optical upper limit
  63. GRB 240825A: Montarrenti Observatory optical follow-up observations
  64. GRB 240905E: Nanshan/HMT optical upper limit
  65. Swift GRB 240905E: Global MASTER-Net observations report
  66. GRB 240905E: Swift detection of a burst
  67. GRB 240819A: Optical upper limits from TESS
  68. Swift GRB 240904A: Global MASTER-Net observations report
  69. GRB 240904A: Swift detection of a burst
  70. LIGO/Virgo/KAGRA S240825ar: Upper limits from Swift/BAT-GUANO
  71. LIGO/Virgo/KAGRA S240807h: Upper limits from Swift/BAT-GUANO
  72. GRB 240828A: GECAM detection
  73. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  74. GRB 240825A: MeerLICHT afterglow detection
  75. GRB 240821A: VLT spectroscopic observations
  76. GRB 240825A: TSHAO Optical Upper Limit
  77. GRB240828B: REM optical/NIR upper limits
  78. GRB 240828B: AbAO optical upper limit
  79. GRB 240828B: Mephisto optical upper limit
  80. GRB 240828B: GRANDMA Optical Upper Limit
  81. GRB 240829A: Swift-BAT refined analysis
  82. GRB 240825A: Swift-BAT refined analysis
  83. GRB 240828B: J-band upper limit from WINTER
  84. GRB 240828B: GMG Optical Upper Limit
  85. GRB 240828A: KAIT continued optical observations
  86. GRB 240828B: GWAC-F50A optical upper limit
  87. GRB 240828B: SVOM/C-GFT optical upper limit
  88. GRB 240828B: SAO RAS optical upper limit
  89. GRB 240828B: KAIT optical upper limit
  90. GRB 240828A: Fermi GBM Observation
  91. GRB 240828A: KAIT Optical Afterglow Candidate
  92. GRB 240825A: SVOM/VT optical detection
  93. GRB 240828A: Swift-XRT afterglow detection
  94. GRB 240825A: iTelescope optical observations
  95. GRB 240828B: Swift-XRT afterglow detection
  96. GRB 240829A: Swift detection of a burst
  97. Swift GRB240829.16: Global MASTER-Net observations report
  98. GRB 240828A: Fermi-LAT detection
  99. GRB 240828A: Tiled Swift observations
  100. GRB 240825A: Upper limits from a neutrino search with IceCube

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