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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"

11756 results found.

  1. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  2. GRB 251115A: Fermi GBM Final Real-time Localization
  3. GRB 251113A: AstroSat CZTI detection
  4. GRB 251114B: Fermi GBM Final Real-time Localization
  5. Konus-Wind detection of GRB 251108C
  6. Konus-Wind detection of GRB 251103A
  7. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  8. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  9. GRB 251111A: SVOM/ECLAIRs refined analysis
  10. GRB 251108C: AstroSat CZTI detection
  11. GRB 251112B: MAXI/GSC detection
  12. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  13. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 3-Initial Localization Volume
  14. GRB 251111A: Swift-XRT observations
  15. GRB 251111A: KAIT optical upper limit
  16. GRB 251111A: SVOM detection of a soft burst
  17. GRB 251105A: AstroSat CZTI detection
  18. IceCube-Cascade 251107A: Upper limits from a search for additional neutrino events in IceCube
  19. Fermi trigger No 784279167: Global MASTER-Net observations report
  20. SVOM GRB251108.54: Global MASTER-Net observations report
  21. SVOM GRB251106.83: Global MASTER-Net observations report
  22. GRB 251106A: Swift-XRT afterglow detection
  23. GRB 251106A: Swift/BAT arcminute localization of a burst
  24. GRB 251106A: MASTER optical observations
  25. GRB 251103B: AstroSat CZTI detection
  26. Fermi trigger No 784034269: Global MASTER-Net observations report
  27. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  28. EP251102a: update of EP-FXT follow-up observation
  29. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  30. LIGO/Virgo/KAGRA S251103f: Identification of a GW compact binary merger candidate
  31. GRB 251103B: GROWTH-India Telescope optical upper limits
  32. GRB 251103A: Swift-XRT afterglow detection
  33. EP251102a: Einstein Probe detection of a fast X-ray transient
  34. GRB 251102A: AstroSat CZTI detection
  35. Fermi GRB 251102A: Global MASTER-Net observations report
  36. GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
  37. Konus-Wind detection of GRB 251028A
  38. IceCube-251025A: Two Transient Candidates from the Zwicky Transient Facility
  39. GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
  40. Fermi GRB 251028B: Global MASTER-Net observations report
  41. GRB251025B: 3.6m DOT Optical Observations
  42. GRB 251028A: MAXI/GSC detection
  43. GRB 251013C : 3.4-m telescope of Iranian National Observatory (INO340) optical observations
  44. Fermi-LAT Gamma-ray Observations of IceCube-251025A
  45. Konus-Wind detection of GRB 251022A
  46. GRB 251027A: Swift-XRT observations
  47. GRB 251022A: SVOM/GRM observation
  48. GRB 251017A: Mondy AZT-33IK and Koshka Zeiss-1000 optical observations
  49. GRB 251026A: Mondy optical upper limit
  50. GRB 251025B: Kilonova-Catcher optical afterglow detection
  51. Konus-Wind detection of GRB 251016A (short/hard)
  52. GRB 251027A: SVOM detection of a faint burst
  53. GRB 251025C: AstroSat CZTI detection
  54. EP251023a: Mondy optical observations
  55. Fermi GRB 251026B: Global MASTER-Net observations report
  56. Fermi GRB 251025C: Global MASTER-Net observations report
  57. GRB 251026A: Swift-XRT observations
  58. GRB 251025B: OHP/T193 optical detection
  59. Konus-Wind detection of GRB 251016B
  60. GRB 251024A: Swift/UVOT Upper Limits
  61. GRB 251025B: Swift-XRT afterglow detection
  62. GRB 251024A: Swift-XRT refined Analysis
  63. GRB 251025B: MASTER OT detection
  64. GRB 251025A: SVOM detection of a faint burst
  65. GRB 251024A: Swift detection of a burst
  66. Swift GRB 251024A: Global MASTER-Net observations report
  67. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  68. GRB 251023C: AstroSat CZTI detection
  69. EP251023b: Global MASTER-Net observations report
  70. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  71. EP251023a: GROWTH-India Telescope optical observations
  72. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  73. EP#01709247298: Swift-XRT counterpart detection
  74. GRB 251013C: further SAO RAS optical observations
  75. GRB 251013C: ISON-Castelgrande observatory optical observations
  76. GRB 251022A: MASTER OT detection
  77. EP251021b/GRB 251021A: SVOM/VT optical candidate
  78. GRB 251023B / MAXI J0451+122: MAXI/GSC detection
  79. Fermi GRB 251023A: Global MASTER-Net observations report
  80. EP251023a: Einstein Probe detection of an X-ray transient
  81. EP/WXT 01709247295: GOTO optical afterglow candidate.
  82. GRB 251022A: GOTO optical counterpart detection
  83. GRB 251022A: Fermi-LAT detection
  84. EP251021b: BOOTES-7 optical upper limit
  85. EP251021b: Einstein Probe detection of a fast X-ray transient
  86. GRB 251016A: SVOM/ECLAIRs refined analysis
  87. Fermi-LAT gamma-ray observations of IceCube-251018A
  88. GRB 251018A: Swift-XRT refined Analysis
  89. IceCube-251018A: Global MASTER-Net observations report
  90. GRB 251017A: COLIBRÍ photometric redshift
  91. GRB 251017A: Swift-XRT refined Analysis
  92. Swift GRB 251018A: Global MASTER-Net observations report
  93. GRB 251016A: AstroSat CZTI detection of a short burst
  94. GRB 251016B: AstroSat CZTI detection
  95. GRB 251017A: Swift detection of a burst with an optical counterpart
  96. sb25101602: Swift-XRT counterpart detection
  97. GRB 251016A: SVOM detection of a short burst
  98. Fermi-LAT Gamma-ray Observations of IceCube-251014A
  99. Konus-Wind detection of GRB 251007A
  100. GRB 251014B: VLT/FORS2 Optical Observation

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