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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').
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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"

19321 results found.

  1. IceCube-Cascade 251112A: Upper limits from a search for additional neutrino events in IceCube
  2. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  3. Fermi GRB 251115A: Global MASTER-Net observations report
  4. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  5. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  6. GRB 251113A: Glowbug gamma-ray detection
  7. GRB 251112A: Swift-BAT refined analysis
  8. Fermi trigger No 784717756: Global MASTER-Net observations report
  9. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  10. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  11. Fermi GRB 251114A: Global MASTER-Net observations report
  12. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  13. Fermi GRB 251113A: Global MASTER-Net observations report
  14. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  15. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  16. GRB 251112A: Swift-XRT refined Analysis
  17. GRB 251108C: AstroSat CZTI detection
  18. GRB 251112B: MAXI/GSC detection
  19. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  20. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  21. GRB 251108B: Glowbug gamma-ray detection
  22. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  23. Fermi trigger No 784621743: Global MASTER-Net observations report
  24. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 3-Initial Localization Volume
  25. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  26. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  27. GRB 251111A: Swift-XRT afterglow detection
  28. SVOM GRB251111.42: Global MASTER-Net observations report
  29. GRB 251111A: Swift-XRT observations
  30. SVOM GRB251111.22: Global MASTER-Net observations report
  31. GRB 251111A: EP-FXT counterpart detection
  32. GRB 251013C: Chandra X-ray observations and jet break detection
  33. GRB 251111A: SVOM detection of a soft burst
  34. GRB 251103B: Swift-BAT refined analysis
  35. GRB 251105A: AstroSat CZTI detection
  36. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  37. IceCube-Cascade 251107A: Upper limits from a search for additional neutrino events in IceCube
  38. LIGO/Virgo/KAGRA S251108fi: Updated Sky localization
  39. LIGO/Virgo/KAGRA S251108dn: Updated Sky localization
  40. Fermi trigger No 784329591: Global MASTER-Net observations report
  41. LIGO/Virgo/KAGRA S251108fi: Identification of a GW compact binary merger candidate
  42. Fermi trigger No 784279167: Global MASTER-Net observations report
  43. SVOM GRB251108.54: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S251108dn: Identification of a GW compact binary merger candidate
  45. SVOM GRB251106.83: Global MASTER-Net observations report
  46. LIGO/Virgo/KAGRA S251105aj: Updated Sky localization
  47. LIGO/Virgo/KAGRA S251103f: Updated Sky localization
  48. GRB 251106A: Swift-XRT afterglow detection
  49. Fermi GBM Sub-Threshold Detection of GRB 251106A
  50. GRB 251106A: MASTER optical observations
  51. GRB 251103B: AstroSat CZTI detection
  52. GRB 251025C: TERI Gamma-ray detection
  53. GRB 251016B: TERI Gamma-ray detection
  54. GRB 251016A: TERI Gamma-ray detection of a short burst
  55. GRB 250920C: TERI Gamma-ray detection
  56. Fermi trigger No 784034269: Global MASTER-Net observations report
  57. GRB 251105A: Fermi GBM Observation
  58. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  59. Fermi GBM Sub-Threshold Detection of GRB 251105B
  60. LIGO/Virgo/KAGRA S251105aj: Identification of a GW compact binary merger candidate
  61. GRB 251103B: Fermi GBM observation
  62. EP251102a: FTW optical and NIR observations
  63. GRB 251103A: OHP/T193 optical observations
  64. GRB 251103B: Nanshan/HMT optical upper limit
  65. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  66. GRB 251103A: Swift/BAT-GUANO arcminute localization of a burst
  67. GRB 251103B: Swift-XRT refined Analysis
  68. LIGO/Virgo/KAGRA S251103f: Identification of a GW compact binary merger candidate
  69. EP251102a: NIR observations with WINTER
  70. GRB 251103A: J-band detection with WINTER
  71. GRB 251103B: Enhanced Swift-XRT position
  72. GRB 251103B: Swift detection of a burst
  73. GRB 251103A: Fermi GBM Observation
  74. GRB 251103A: SVOM/GRM observation
  75. GRB 251103A: Swift-XRT afterglow detection
  76. LIGO/Virgo/KAGRA S251031cq: Updated Sky localization
  77. GRB 251103A: LCO optical observation
  78. EP251102.890: COLIBRÍ optical counterpart candidate
  79. GRB 251031A: Fermi GBM Observation
  80. LIGO/Virgo/KAGRA S251031cq: Identification of a GW compact binary merger candidate
  81. GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
  82. GRB 251031A: BALROG localization (Fermi Trigger 783588065 / GRB 251031306)
  83. GRB 251028A: Fermi GBM Observation
  84. GRB 250926A: VZLUSAT-2 detection
  85. GRB 251026B: Fermi GBM Observation
  86. GRB 251026A/EP251026a: SVOM/VT optical counterpart
  87. GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
  88. GRB 251028B: Glowbug gamma-ray detection
  89. GRB 251028A: Glowbug gamma-ray detection
  90. GRB 251028A: BALROG localization (Fermi Trigger 783314796 / GRB 251028143)
  91. GRB 251028A: MAXI/GSC detection
  92. IceCube-251025A: Upper limits from a search for additional neutrino events in IceCube
  93. GRB 251026B: Swift-XRT observations of GOTO25jgl/AT2025absf
  94. GRB 251025C: Glowbug gamma-ray detection
  95. Fermi-LAT Gamma-ray Observations of IceCube-251025A
  96. GRB 251027A: Swift-XRT observations
  97. GRB 251017A: Mondy AZT-33IK and Koshka Zeiss-1000 optical observations
  98. GRB 251027A: SVOM detection of a faint burst
  99. LIGO/Virgo/KAGRA S251026bn: Updated Sky localization
  100. Fermi GRB 251025C: Global MASTER-Net observations report

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