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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

12314 results found.

  1. Fermi GRB 260926A: Global MASTER-Net observations report
  2. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  3. GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  4. EP260924a: J-band upper limit by SYSU 80cm infrared telescope
  5. GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
  6. GRB 260925A: Swift/UVOT Upper Limits
  7. GRB 260925A: COLIBRÍ optical upper limits
  8. EP260924a: J-band upper limit with WINTER
  9. GRB 260924A: Swift/UVOT Detection
  10. GRB 260924A: Swift/UVOT Upper Limits
  11. Konus-Wind detection of GRB 260922A
  12. Konus-Wind detection of GRB 260921A (possible merger-origin)
  13. Fermi GRB 260923A: Global MASTER-Net observations report
  14. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  15. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  16. GRB 260922A: J-band upper limit with WINTER
  17. GRB 260922A: Swift/UVOT Upper Limits
  18. GRB 260922A: COLIBRÍ optical upper limits
  19. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  20. GRB 260922A: SVOM/C-GFT optical upper limit
  21. GRB 260922A: Swift detection of a burst
  22. EP Alert 260921.58: Global MASTER-Net observations report
  23. Swift GRB 260921A: Global MASTER-Net observations report
  24. EP Alert 260921.01: Global MASTER-Net observations report
  25. EP260920b: Global MASTER-Net observations report
  26. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  27. EP Alert 260920.66: Global MASTER-Net observations report
  28. EP260920a: NOT early time optical upper limits
  29. EP260920a: NOT optical upper limits
  30. EP260920a: SVOM/VT optical upper limits
  31. EP260917a: Global MASTER-Net observations report
  32. EP260920a: COLIBRÍ optical upper limits
  33. EP260917b: EP-FXT non-detection and upper limit
  34. IceCube Alert 260919A: Global MASTER-Net observations report
  35. EP Alert 260919.40: Global MASTER-Net observations report
  36. GRB 260915A: VLT optical and near-infrared upper limits
  37. EP260806a: Yamaguchi Interferometer radio detections
  38. EP260917a: SVOM/VT optical upper limits
  39. GRB 260918A: SVOM/C-GFT optical upper limits
  40. EP Alert 260918.62: Global MASTER-Net observations report
  41. EP Alert 260918.24: Global MASTER-Net observations report
  42. SVOM GRB260918.16: Global MASTER-Net observations report
  43. Konus-Wind detection of GRB 260916B (short/hard)
  44. GRB 260918A: SVOM/VT optical upper limits
  45. GRB 260917B: Mondy optical upper limit
  46. EP260917A: J-band upper limit with WINTER
  47. EP Alert 260917.32: Global MASTER-Net observations report
  48. EP260917a: COLIBRÍ optical upper limits
  49. GRB 260918A: LCO optical upper limits
  50. GRB 260918A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  51. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  52. SVOM GRB260917.16: Global MASTER-Net observations report
  53. Fermi trigger No 811304653: Global MASTER-Net observations report
  54. GRB 260915A: J-band upper limit with WINTER
  55. Fermi trigger No 811264269: Global MASTER-Net observations report
  56. GRB 260909A: Swift-XRT observations
  57. GRB 260916A: MAXI/GSC detection
  58. MAXI GRB260916.37: Global MASTER-Net observations report
  59. GRB 260915A: J-band upper limit by SYSU 80cm infrared telescope
  60. GRB 260915A: SVOM/C-GFT optical upper limits
  61. GRB 260915A: SVOM/VT refined early optical upper limits
  62. GRB 260915A: SVOM/VT optical upper limits
  63. GRB 260915A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  64. GRB 260915A: NOT optical upper limit
  65. SVOM GRB260915.05: Global MASTER-Net observations report
  66. GRB 260915A: SVOM/VT optical upper limits from VHF data
  67. GRB 260915A: LCO optical upper limits
  68. EP Alert 260914.53: Global MASTER-Net observations report
  69. SVOM GRB260914.47: Global MASTER-Net observations report
  70. SVOM GRB260913.32: Global MASTER-Net observations report
  71. GRB 260913A: SVOM/C-GFT optical upper limit
  72. GRB 260909A: OSN 1.5m, CAHA 2.2m and GTC 10.4m optical upper limits
  73. GRB 260909A: CrAO and AbAO optical upper limits
  74. GRB 260909A: KAIT optical upper limit
  75. GRB 260903A: Swift-XRT observations
  76. GRB 260909A: OHP/T193 z-band upper limit
  77. GRB 260909A: VLT optical and near-infrared upper limits
  78. EP Alert 260909.53: Global MASTER-Net observations report
  79. GRB 260909A: SVOM/VT optical upper limits
  80. GRB 260909A: Mondy optical observations and afterglow candidate
  81. GRB 260909A: Xinglong 2.16m optical upper limit
  82. GRB 260909A: SVOM/C-GFT optical upper limit
  83. Fermi trigger No 810554827: Global MASTER-Net observations report
  84. EP Alert 260908.60: Global MASTER-Net observations report
  85. Fermi GRB 260907B: Global MASTER-Net observations report
  86. GRB 260903A: SAO RAS optical upper limit
  87. Fermi GRB 260907A: Global MASTER-Net observations report
  88. EP Alert 260905.11: Global MASTER-Net observations report
  89. GRB 260903A: J-band upper limit with WINTER
  90. EP Alert 260903.47: Global MASTER-Net observations report
  91. GRB260903A: Liverpool Telescope optical observations
  92. EP Alert 260903.62: Global MASTER-Net observations report
  93. NuSTAR Transient 260828: SOAR Optical Upper Limits
  94. SVOM GRB260903A: Global MASTER-Net observations report
  95. EP260901a: SVOM/VT optical upper limits
  96. EP260901a: EP-FXT follow-up observation
  97. Konus-Wind detection of GRB 260829A
  98. EP260830a: EP-FXT follow-up observation
  99. EP260901a: Global MASTER-Net observations report
  100. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per

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