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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. Fermi GRB 241104A: Global MASTER-Net observations report
  2. EP241101a: EP-FXT observations update
  3. EP241103a: GIT optical upper limit
  4. Fermi trigger No 752365806: Global MASTER-Net observations report
  5. EP241103a: GOTO optical upper limit
  6. EP241101a: Possible detection of an optical counterpart with FTW
  7. EP241101a: Optical upper limits with Kinder observations
  8. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  9. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  10. EP241103a: GSP optical upper limit
  11. EP241103a: Global MASTER-Net observations report
  12. EP241101a: Global MASTER-Net observations report
  13. EP241101a: BOOTES-7 optical upper limit
  14. EP241101a: EP-WXT detection of a fast X-ray transient
  15. Swift GRB 241101A: Global MASTER-Net observations report
  16. EP241021a: Upper limit from Konus-Wind observations
  17. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  18. GRB 241030B: Montarrenti Observatory optical upper limit
  19. EP241026b: Liverpool Telescope optical follow-up
  20. Fermi trigger No 752083996: Global MASTER-Net observations report
  21. GRB 241030B : GIT optical upper limits
  22. GRB 241030B: LCOGT Optical Upper Limits
  23. GRB 241030B: Swift/UVOT Detection
  24. EP EP241030a: Global MASTER-Net observations report
  25. Fermi trigger No 752006065: Global MASTER-Net observations report
  26. Swift GRB241030.77: Global MASTER-Net observations report
  27. GRB 241030B : MITSuME Akeno optical upper limits
  28. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  29. GRB 241030B: optical observations from the INAF Asiago Observatory
  30. GRB241030B: GRANDMA/TAROT Upper Limit
  31. Konus-Wind detection of GRB 241030A
  32. GRB 241030B: Swift detection of a burst
  33. Fermi GRB 241030A: Global MASTER-Net observations report
  34. Swift GRB 241030A: Global MASTER-Net observations report
  35. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  36. GRB 241026A: Swift/UVOT Upper Limits
  37. GRB 241029A: Swift-XRT observations
  38. Fermi trigger No 751861204: Global MASTER-Net observations report
  39. EP241026B: GROWTH-India Telescope optical upper limit
  40. GRB 241025A: Swift/UVOT Detection
  41. GRB 241026A: J-band observations with WINTER
  42. EP241021a: e-MERLIN radio observation
  43. EP EP241026b: Global MASTER-Net observations report
  44. Fermi trigger No 751616906: Global MASTER-Net observations report
  45. Fermi GRB 241026A: Global MASTER-Net observations report
  46. Swift GRB241026.95: Global MASTER-Net observations report
  47. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  48. Fermi trigger No 751563375: Global MASTER-Net observations report
  49. Fermi trigger No 751554401: Global MASTER-Net observations report
  50. EP 241021a: Swift-XRT observations
  51. Fermi GRB 241025A: Global MASTER-Net observations report
  52. Swift GRB 241025A: Global MASTER-Net observations report
  53. Fermi GRB 241024B: Global MASTER-Net observations report
  54. GRB 241010A: VIRT Optical Upper Limit
  55. Fermi trigger No 751449953: Global MASTER-Net observations report
  56. EP241021a: Optical upper limits with Kinder observations
  57. EP EP241021a: Global MASTER-Net observations report
  58. GRB241017A: 1.3m DFOT optical upper limit
  59. GRB 241018A: 1.3m DFOT Optical upper limit
  60. EP241021a: GOTO optical upper limits
  61. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  62. GRB 241018A/sb24101802: Mephisto optical upper limit
  63. GRB 241017A/sb24101702: Mephisto optical upper limit
  64. GRB 241018A: BOOTES-4/MET optical upper limit
  65. GRB 241018A: Mondy optical upper limit
  66. GRB 241018A: GROWTH-India telescope optical upper limit
  67. GRB241018A: XingLong Optical Upper Limit
  68. GRB 241018A: Swift-XRT observations
  69. GRB 241018A: REM optical/NIR upper limits
  70. GRB 241017A: SVOM/VT follow-up and optical upper limit
  71. GRB 241018A: LCO/0.4m optical upper limits
  72. GRB 241006A: VIRT Optical Upper Limit
  73. GRB 240727A: VIRT Optical Upper Limit
  74. GRB 241017A: Swift-XRT observations
  75. GRB 241017A: GROWTH-India Telescope optical upper limit
  76. GRB 241017A: J-band upper limit from WINTER
  77. Fermi trigger No 750788395: Global MASTER-Net observations report
  78. Fermi GRB 241016B: Global MASTER-Net observations report
  79. Fermi GRB 241016A: Global MASTER-Net observations report
  80. IceCube Alert 241016.04: Global MASTER-Net observations report
  81. GRB 241009A: LCO optical upper limits
  82. Fermi GRB 241013B: Global MASTER-Net observations report
  83. Integral GRB241013.04: Global MASTER-Net observations report
  84. GRB 241009A: GRANDMA optical upper limits
  85. GRB 241009A: Swift-XRT afterglow detection
  86. GRB 241006A: ATCA Radio Upper Limits
  87. Fermi trigger No 750211959: Global MASTER-Net observations report
  88. Swift GRB 241010A: Global MASTER-Net observations report
  89. Fermi trigger No 750291012: Global MASTER-Net observations report
  90. GRB 241010A: J-band observations with WINTER
  91. Fermi GRB 241010B: Global MASTER-Net observations report
  92. IceCube-241006A: Upper limits from a search for additional neutrino events in IceCube
  93. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  94. GRB 241002A: NOT optical upper limits
  95. Fermi GRB 241008A: Global MASTER-Net observations report
  96. GRB 241006A: GRANDMA optical upper limits
  97. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  98. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  99. GRB 241006A: PRIME near-infrared upper limits
  100. GRB 241006A: Swift/UVOT Upper Limits

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