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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"

11761 results found.

  1. GRB 251025B: further Mondy optical observations
  2. SVOM GRB251116C: Global MASTER-Net observations report
  3. GRB 251116C: SVOM detection of a burst
  4. GRB 251115A: Fermi-LAT detection
  5. Fermi GRB 251115A: Global MASTER-Net observations report
  6. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  7. GRB 251115A: Fermi GBM Final Real-time Localization
  8. GRB 251113A: AstroSat CZTI detection
  9. GRB 251114B: Fermi GBM Final Real-time Localization
  10. Konus-Wind detection of GRB 251108C
  11. Konus-Wind detection of GRB 251103A
  12. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  13. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  14. GRB 251111A: SVOM/ECLAIRs refined analysis
  15. GRB 251108C: AstroSat CZTI detection
  16. GRB 251112B: MAXI/GSC detection
  17. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  18. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 3-Initial Localization Volume
  19. GRB 251111A: Swift-XRT observations
  20. GRB 251111A: KAIT optical upper limit
  21. GRB 251111A: SVOM detection of a soft burst
  22. GRB 251105A: AstroSat CZTI detection
  23. IceCube-Cascade 251107A: Upper limits from a search for additional neutrino events in IceCube
  24. Fermi trigger No 784279167: Global MASTER-Net observations report
  25. SVOM GRB251108.54: Global MASTER-Net observations report
  26. SVOM GRB251106.83: Global MASTER-Net observations report
  27. GRB 251106A: Swift-XRT afterglow detection
  28. GRB 251106A: Swift/BAT arcminute localization of a burst
  29. GRB 251106A: MASTER optical observations
  30. GRB 251103B: AstroSat CZTI detection
  31. Fermi trigger No 784034269: Global MASTER-Net observations report
  32. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  33. EP251102a: update of EP-FXT follow-up observation
  34. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  35. LIGO/Virgo/KAGRA S251103f: Identification of a GW compact binary merger candidate
  36. GRB 251103B: GROWTH-India Telescope optical upper limits
  37. GRB 251103A: Swift-XRT afterglow detection
  38. EP251102a: Einstein Probe detection of a fast X-ray transient
  39. GRB 251102A: AstroSat CZTI detection
  40. Fermi GRB 251102A: Global MASTER-Net observations report
  41. GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
  42. Konus-Wind detection of GRB 251028A
  43. IceCube-251025A: Two Transient Candidates from the Zwicky Transient Facility
  44. GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
  45. Fermi GRB 251028B: Global MASTER-Net observations report
  46. GRB251025B: 3.6m DOT Optical Observations
  47. GRB 251028A: MAXI/GSC detection
  48. GRB 251013C : 3.4-m telescope of Iranian National Observatory (INO340) optical observations
  49. Fermi-LAT Gamma-ray Observations of IceCube-251025A
  50. Konus-Wind detection of GRB 251022A
  51. GRB 251027A: Swift-XRT observations
  52. GRB 251022A: SVOM/GRM observation
  53. GRB 251017A: Mondy AZT-33IK and Koshka Zeiss-1000 optical observations
  54. GRB 251026A: Mondy optical upper limit
  55. GRB 251025B: Kilonova-Catcher optical afterglow detection
  56. Konus-Wind detection of GRB 251016A (short/hard)
  57. GRB 251027A: SVOM detection of a faint burst
  58. GRB 251025C: AstroSat CZTI detection
  59. EP251023a: Mondy optical observations
  60. Fermi GRB 251026B: Global MASTER-Net observations report
  61. Fermi GRB 251025C: Global MASTER-Net observations report
  62. GRB 251026A: Swift-XRT observations
  63. GRB 251025B: OHP/T193 optical detection
  64. Konus-Wind detection of GRB 251016B
  65. GRB 251024A: Swift/UVOT Upper Limits
  66. GRB 251025B: Swift-XRT afterglow detection
  67. GRB 251024A: Swift-XRT refined Analysis
  68. GRB 251025B: MASTER OT detection
  69. GRB 251025A: SVOM detection of a faint burst
  70. GRB 251024A: Swift detection of a burst
  71. Swift GRB 251024A: Global MASTER-Net observations report
  72. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  73. GRB 251023C: AstroSat CZTI detection
  74. EP251023b: Global MASTER-Net observations report
  75. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  76. EP251023a: GROWTH-India Telescope optical observations
  77. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  78. EP#01709247298: Swift-XRT counterpart detection
  79. GRB 251013C: further SAO RAS optical observations
  80. GRB 251013C: ISON-Castelgrande observatory optical observations
  81. GRB 251022A: MASTER OT detection
  82. EP251021b/GRB 251021A: SVOM/VT optical candidate
  83. GRB 251023B / MAXI J0451+122: MAXI/GSC detection
  84. Fermi GRB 251023A: Global MASTER-Net observations report
  85. EP251023a: Einstein Probe detection of an X-ray transient
  86. EP/WXT 01709247295: GOTO optical afterglow candidate.
  87. GRB 251022A: GOTO optical counterpart detection
  88. GRB 251022A: Fermi-LAT detection
  89. EP251021b: BOOTES-7 optical upper limit
  90. EP251021b: Einstein Probe detection of a fast X-ray transient
  91. GRB 251016A: SVOM/ECLAIRs refined analysis
  92. Fermi-LAT gamma-ray observations of IceCube-251018A
  93. GRB 251018A: Swift-XRT refined Analysis
  94. IceCube-251018A: Global MASTER-Net observations report
  95. GRB 251017A: COLIBRÍ photometric redshift
  96. GRB 251017A: Swift-XRT refined Analysis
  97. Swift GRB 251018A: Global MASTER-Net observations report
  98. GRB 251016A: AstroSat CZTI detection of a short burst
  99. GRB 251016B: AstroSat CZTI detection
  100. GRB 251017A: Swift detection of a burst with an optical counterpart

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