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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"

12400 results found.

  1. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  2. Fermi GRB 240905D: Global MASTER-Net observations report
  3. Fermi GRB 240905A: Global MASTER-Net observations report
  4. GRB 240905E: NOT optical upper limits
  5. GRB 240905E: REM optical/NIR upper limits
  6. GRB 240905E: LCOGT Optical Upper Limit
  7. GRB 240905E: Swift/UVOT Upper Limits
  8. GRB 240905E: SAO RAS optical upper limit
  9. GRB 240905E: Nanshan/HMT optical upper limit
  10. Swift GRB 240905E: Global MASTER-Net observations report
  11. GRB 240819A: Optical upper limits from TESS
  12. Fermi GRB 240905B: Global MASTER-Net observations report
  13. Swift GRB 240904A: Global MASTER-Net observations report
  14. Fermi trigger No 747163821: Global MASTER-Net observations report
  15. LIGO/Virgo/KAGRA S240825ar: Upper limits from Swift/BAT-GUANO
  16. LIGO/Virgo/KAGRA S240807h: Upper limits from Swift/BAT-GUANO
  17. Fermi trigger No 746923430: Global MASTER-Net observations report
  18. Fermi trigger No 746882332: Global MASTER-Net observations report
  19. GRB 240825A: TSHAO Optical Upper Limit
  20. GRB240828B: REM optical/NIR upper limits
  21. Fermi trigger No 746816563: Global MASTER-Net observations report
  22. GRB 240828B: AbAO optical upper limit
  23. GRB 240825A: SOAR observations
  24. GRB 240828B: Mephisto optical upper limit
  25. GRB 240828B: GRANDMA Optical Upper Limit
  26. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  27. GRB 240828B: J-band upper limit from WINTER
  28. Fermi trigger No 746684112: Global MASTER-Net observations report
  29. GRB 240828B: GMG Optical Upper Limit
  30. GRB 240828B: GWAC-F50A optical upper limit
  31. GRB 240828B: SVOM/C-GFT optical upper limit
  32. GRB 240828B: SAO RAS optical upper limit
  33. GRB 240828B: KAIT optical upper limit
  34. Fermi trigger No 746587425: Global MASTER-Net observations report
  35. GRB 240828A: Swift-XRT afterglow detection
  36. GRB 240828B: Swift-XRT afterglow detection
  37. Swift GRB240829.16: Global MASTER-Net observations report
  38. LAT GRB240828.62: Global MASTER-Net observations report
  39. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  40. GRB 240825A: Upper limits from a neutrino search with IceCube
  41. GRB 240819A as a likely X-Ray Flash
  42. Fermi GRB 240828A: Global MASTER-Net observations report
  43. Fermi trigger No 746438824: Global MASTER-Net observations report
  44. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  45. GRB 240824A: GIT optical upper limit
  46. GRB 240819A: Swift afterglow confirmation
  47. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  48. GRB 240824B: KAIT optical upper limit
  49. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  50. Fermi GRB 240825A: Global MASTER-Net observations report
  51. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  52. GRB 240824B: NOT optical upper limit
  53. Swift GRB 240825A: Global MASTER-Net observations report
  54. GRB 240824A: SVOM/C-GFT optical upper limit
  55. GRB 240824A: Swift-XRT observations
  56. Fermi GRB 240824C: Global MASTER-Net observations report
  57. GRB 240824A: Swift/UVOT Upper Limits
  58. GRB 240821A: Swift/UVOT observations of the XRT sources.
  59. GRB 240824B: MAXI/GSC detection
  60. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  61. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  62. GRB 240824A: KAIT optical upper limit
  63. GRB 240824A: Swift detection of a burst
  64. Swift GRB240824.04: Global MASTER-Net observations report
  65. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  66. GRB 240821A: Colibri Optical Upper Limit
  67. GRB 240821A: Swift-XRT observations
  68. GRB 240821A: REM optical/NIR upper limits
  69. GRB 240821A: JinShan optical upper limits
  70. GRB 240821A: SVOM/VT follow-up and optical upper limit
  71. GRB 240821A: GMG Optical Upper Limit
  72. Fermi GRB 240821A: Global MASTER-Net observations report
  73. Fermi trigger No 745964969: Global MASTER-Net observations report
  74. Fermi trigger No 745925274: Global MASTER-Net observations report
  75. Fermi trigger No 746019401: Global MASTER-Net observations report
  76. Fermi trigger No 745935375: Global MASTER-Net observations report
  77. Fermi GRB 240821B: Global MASTER-Net observations report
  78. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  79. Fermi trigger No 745866488: Global MASTER-Net observations report
  80. GRB 240819A: Swift-XRT observations
  81. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  82. EP240820a: TRT optical upper limit
  83. GRB 240819A: KAIT optical upper limit
  84. EP240816a: PRIME upper limits
  85. Fermi trigger No 745873283: Global MASTER-Net observations report
  86. Fermi trigger No 745871958: Global MASTER-Net observations report
  87. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  88. EP240816a: BOOTES-6/DPRT optical upper limit
  89. Integral GRB240816.79: Global MASTER-Net observations report
  90. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  91. EP240816b: KAIT optical upper limit
  92. Fermi trigger No 745501396: Global MASTER-Net observations report
  93. EP EP240816b: Global MASTER-Net observations report
  94. EP240816b: TRT optical upper limit
  95. Fermi GRB 240814A: Global MASTER-Net observations report
  96. Fermi GRB 240814C: Global MASTER-Net observations report
  97. Fermi trigger No 745306088: Global MASTER-Net observations report
  98. Fermi GRB 240814B: Global MASTER-Net observations report
  99. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  100. Fermi trigger No 745220784: Global MASTER-Net observations report

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