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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.

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

11755 results found.

  1. LIGO/Virgo/KAGRA S241109bn: Global MASTER-Net observations report
  2. EP241109a: confirmation of a stellar flare by BOOTES-7
  3. GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
  4. EP241107a: AKO Optical Afterglow Follow-Up Observations
  5. EP241107a: AKO Optical Afterglow Detection
  6. Konus-Wind detection of GRB 241105A (short with extended emission)
  7. Konus-Wind detection of GRB 241021A
  8. Fermi GRB 241105A: Global MASTER-Net observations report
  9. EP241104a: EP detection of GRB 241104A X-ray emission
  10. Fermi GRB 241104A: Global MASTER-Net observations report
  11. EP241103a: GIT optical upper limit
  12. EP241021a: OHP/T193 further optical observations
  13. Fermi trigger No 752365806: Global MASTER-Net observations report
  14. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  15. EP241101a: OHP/T193 optical observations
  16. EP241103a: EP observation update
  17. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  18. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  19. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  20. EP241103a: Global MASTER-Net observations report
  21. EP241103a: an X-ray transient detected by Einstein Probe
  22. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  23. EP241021a: Upper limit from Konus-Wind observations
  24. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  25. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  26. EP241026b: Liverpool Telescope optical follow-up
  27. Fermi trigger No 752083996: Global MASTER-Net observations report
  28. GRB 241030A: SAO RAS optical observations
  29. GRB 241030A: Fermi GBM Observation
  30. EP241021a: AMI-LA radio detection
  31. GRB 241030B : GIT optical upper limits
  32. EP EP241030a: Global MASTER-Net observations report
  33. Fermi trigger No 752006065: Global MASTER-Net observations report
  34. Swift GRB241030.77: Global MASTER-Net observations report
  35. GRB241030B: Fermi GBM Observation
  36. GRB 241030B: BTA observations
  37. GRB 241030B: optical observations from the INAF Asiago Observatory
  38. GRB 241030B: Nanshan/HMT optical afterglow detection
  39. Konus-Wind detection of GRB 241030A
  40. GRB 241030B: Swift detection of a burst
  41. GRB 241030B: Fermi GBM Final Real-time Localization
  42. GRB 241030A: Fermi-LAT detection
  43. GRB 241030A: Swift/UVOT Detection
  44. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  45. EP241021a: ATCA radio observations
  46. GRB 241029A: Fermi GBM Observation
  47. Fermi trigger No 751861204: Global MASTER-Net observations report
  48. Konus-Wind detection of GRB 241025A
  49. GRB 241025A: further SAO RAS optical observations
  50. GRB 241026A: BTA and Zeiss-1000 optical observations
  51. GRB 241026A Fermi GBM Analysis
  52. GRB 241025A: SAO RAS optical observations
  53. EP241021a: further SAO RAS optical observations
  54. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  55. GRB 241026A: Swift-XRT refined Analysis
  56. GRB 241026A: SAO RAS observations of possible optical afterglow
  57. GRB 241026A: Swift detection of a burst
  58. Swift GRB241026.95: Global MASTER-Net observations report
  59. GRB241025A: 1.3m DFOT optical afterglow detection
  60. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  61. Fermi trigger No 751554401: Global MASTER-Net observations report
  62. Fermi GRB 241025A: Global MASTER-Net observations report
  63. GRB 241001A: ATCA radio observations
  64. EP241021a: VLT/FORS2 redshift z = 0.75
  65. Fermi trigger No 751449953: Global MASTER-Net observations report
  66. EP241021a: SAO RAS optical observations
  67. EP241021a: EP-FXT follow-up observation update
  68. GRB241017A: 1.3m DFOT optical upper limit
  69. EP241021a: EP detection of a fast X-ray transient
  70. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  71. Konus-Wind detection of GRB 241018A
  72. GRB 241018A/sb24101802: Mephisto optical upper limit
  73. GRB 240727A: VIRT Optical Upper Limit
  74. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  75. Fermi trigger No 750788395: Global MASTER-Net observations report
  76. Fermi GRB 241016B: Global MASTER-Net observations report
  77. Fermi GRB 241016A: Global MASTER-Net observations report
  78. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  79. GRB241013A: REM observations
  80. GRB 241013A: a long GRB detected by INTEGRAL
  81. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  82. Fermi Gamma-ray Burst Monitor GRB trigger 750372658/241011869 (GRB 241011A) is not a GRB
  83. GRB 241011A: Fermi GBM Final Real-time Localization
  84. GRB 241010A: Swift-XRT refined Analysis
  85. Fermi trigger No 750211959: Global MASTER-Net observations report
  86. Fermi trigger No 750291012: Global MASTER-Net observations report
  87. GRB 241010A: Swift detection of a burst with an optical counterpart
  88. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  89. GRB 241008A: Fermi-LAT detection
  90. GRB 241002B: Swift-XRT afterglow detection
  91. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  92. GRB 240910A: LBT optical observations
  93. GRB 241006A: Swift-XRT refined Analysis
  94. IceCube Alert 241006.94: Global MASTER-Net observations report
  95. GRB 241006A: Swift detection of a burst
  96. Swift GRB241006.91: Global MASTER-Net observations report
  97. EP trigger ID 01709065118: the X-ray transient is likely a stellar flare event
  98. GRB 241001A : ECLAIRs spectral analysis and XRF classification
  99. Fermi trigger No 749693019: Global MASTER-Net observations report
  100. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst

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