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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

12316 results found.

  1. GRB 260924A: Upper limits from a neutrino search with IceCube
  2. Fermi GRB 260926C: Global MASTER-Net observations report
  3. Fermi GRB 260926A: Global MASTER-Net observations report
  4. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  5. GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  6. EP260924a: J-band upper limit by SYSU 80cm infrared telescope
  7. GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
  8. GRB 260925A: Swift/UVOT Upper Limits
  9. GRB 260925A: COLIBRÍ optical upper limits
  10. EP260924a: J-band upper limit with WINTER
  11. GRB 260924A: Swift/UVOT Detection
  12. GRB 260924A: Swift/UVOT Upper Limits
  13. Konus-Wind detection of GRB 260922A
  14. Konus-Wind detection of GRB 260921A (possible merger-origin)
  15. Fermi GRB 260923A: Global MASTER-Net observations report
  16. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  17. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  18. GRB 260922A: J-band upper limit with WINTER
  19. GRB 260922A: Swift/UVOT Upper Limits
  20. GRB 260922A: COLIBRÍ optical upper limits
  21. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  22. GRB 260922A: SVOM/C-GFT optical upper limit
  23. GRB 260922A: Swift detection of a burst
  24. EP Alert 260921.58: Global MASTER-Net observations report
  25. Swift GRB 260921A: Global MASTER-Net observations report
  26. EP Alert 260921.01: Global MASTER-Net observations report
  27. EP260920b: Global MASTER-Net observations report
  28. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  29. EP Alert 260920.66: Global MASTER-Net observations report
  30. EP260920a: NOT early time optical upper limits
  31. EP260920a: NOT optical upper limits
  32. EP260920a: SVOM/VT optical upper limits
  33. EP260917a: Global MASTER-Net observations report
  34. EP260920a: COLIBRÍ optical upper limits
  35. EP260917b: EP-FXT non-detection and upper limit
  36. IceCube Alert 260919A: Global MASTER-Net observations report
  37. EP Alert 260919.40: Global MASTER-Net observations report
  38. GRB 260915A: VLT optical and near-infrared upper limits
  39. EP260806a: Yamaguchi Interferometer radio detections
  40. EP260917a: SVOM/VT optical upper limits
  41. GRB 260918A: SVOM/C-GFT optical upper limits
  42. EP Alert 260918.62: Global MASTER-Net observations report
  43. EP Alert 260918.24: Global MASTER-Net observations report
  44. SVOM GRB260918.16: Global MASTER-Net observations report
  45. Konus-Wind detection of GRB 260916B (short/hard)
  46. GRB 260918A: SVOM/VT optical upper limits
  47. GRB 260917B: Mondy optical upper limit
  48. EP260917A: J-band upper limit with WINTER
  49. EP Alert 260917.32: Global MASTER-Net observations report
  50. EP260917a: COLIBRÍ optical upper limits
  51. GRB 260918A: LCO optical upper limits
  52. GRB 260918A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  53. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  54. SVOM GRB260917.16: Global MASTER-Net observations report
  55. Fermi trigger No 811304653: Global MASTER-Net observations report
  56. GRB 260915A: J-band upper limit with WINTER
  57. Fermi trigger No 811264269: Global MASTER-Net observations report
  58. GRB 260909A: Swift-XRT observations
  59. GRB 260916A: MAXI/GSC detection
  60. MAXI GRB260916.37: Global MASTER-Net observations report
  61. GRB 260915A: J-band upper limit by SYSU 80cm infrared telescope
  62. GRB 260915A: SVOM/C-GFT optical upper limits
  63. GRB 260915A: SVOM/VT refined early optical upper limits
  64. GRB 260915A: SVOM/VT optical upper limits
  65. GRB 260915A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  66. GRB 260915A: NOT optical upper limit
  67. SVOM GRB260915.05: Global MASTER-Net observations report
  68. GRB 260915A: SVOM/VT optical upper limits from VHF data
  69. GRB 260915A: LCO optical upper limits
  70. EP Alert 260914.53: Global MASTER-Net observations report
  71. SVOM GRB260914.47: Global MASTER-Net observations report
  72. SVOM GRB260913.32: Global MASTER-Net observations report
  73. GRB 260913A: SVOM/C-GFT optical upper limit
  74. GRB 260909A: OSN 1.5m, CAHA 2.2m and GTC 10.4m optical upper limits
  75. GRB 260909A: CrAO and AbAO optical upper limits
  76. GRB 260909A: KAIT optical upper limit
  77. GRB 260903A: Swift-XRT observations
  78. GRB 260909A: OHP/T193 z-band upper limit
  79. GRB 260909A: VLT optical and near-infrared upper limits
  80. EP Alert 260909.53: Global MASTER-Net observations report
  81. GRB 260909A: SVOM/VT optical upper limits
  82. GRB 260909A: Mondy optical observations and afterglow candidate
  83. GRB 260909A: Xinglong 2.16m optical upper limit
  84. GRB 260909A: SVOM/C-GFT optical upper limit
  85. Fermi trigger No 810554827: Global MASTER-Net observations report
  86. EP Alert 260908.60: Global MASTER-Net observations report
  87. Fermi GRB 260907B: Global MASTER-Net observations report
  88. GRB 260903A: SAO RAS optical upper limit
  89. Fermi GRB 260907A: Global MASTER-Net observations report
  90. EP Alert 260905.11: Global MASTER-Net observations report
  91. GRB 260903A: J-band upper limit with WINTER
  92. EP Alert 260903.47: Global MASTER-Net observations report
  93. GRB260903A: Liverpool Telescope optical observations
  94. EP Alert 260903.62: Global MASTER-Net observations report
  95. NuSTAR Transient 260828: SOAR Optical Upper Limits
  96. SVOM GRB260903A: Global MASTER-Net observations report
  97. EP260901a: SVOM/VT optical upper limits
  98. EP260901a: EP-FXT follow-up observation
  99. Konus-Wind detection of GRB 260829A
  100. EP260830a: EP-FXT follow-up observation

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