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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"

28123 results found.

  1. GRB 251022A: SVOM/GRM observation
  2. GRB 251026A/EP251026a: Einstein Probe detection of a fast X-ray transient
  3. GRB 251027A: LCO optical upper limit
  4. GRB 251027A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  5. GRB 251017A: Mondy AZT-33IK and Koshka Zeiss-1000 optical observations
  6. GRB 251023B / EP251023b: Mondy optical upper limit
  7. GRB 251017A: INASAN-Kislovodsk optical observations
  8. GRB 251026A: Mondy optical upper limit
  9. GRB 251025B: Mondy optical observations
  10. GRB 251025B: Kilonova-Catcher optical afterglow detection
  11. GRB 251025B: VLT/MUSE spectroscopic redshift z = 2.003
  12. GRB 251027A: SVOM detection of a faint burst
  13. EP251023a: Mondy optical observations
  14. GRB 251025B: MAO/AZT-22 optical observations
  15. LIGO/Virgo/KAGRA S251026bn: Updated Sky localization
  16. Fermi GRB 251025C: Global MASTER-Net observations report
  17. LIGO/Virgo/KAGRA S251026bn: Identification of a GW compact binary merger candidate
  18. GRB 251026A: Swift-XRT observations
  19. GRB 251025B: OHP/T193 optical detection
  20. GRB 251025B: J-band detection with WINTER
  21. GRB 251026A: SVOM/C-GFT upper limit
  22. IceCube-251025A: DDOTI Optical Upper Limit
  23. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  24. GRB 251026A: SVOM detection of a long burst
  25. GRB 251025B: SVOM/COLIBRÍ (FM-GFT) strong rebrightening of the optical counterpart
  26. GRB 251023A: SVOM/GRM observation
  27. GRB 251025B: ULL-ASTRO-MASTER optical counterpart detection with IAC80 telescope at Teide Observatory
  28. GRB 251025B: GROWTH-India Telescope optical observations
  29. GRB 251024A: Swift/UVOT Upper Limits
  30. GRB 251025B: Swift-XRT afterglow detection
  31. GRB 251024A: Swift-BAT refined analysis
  32. GRB 251024A: Swift-XRT refined Analysis
  33. GRB 251025A (sb25102501): stellar flare confirmed
  34. GRB 251025B: SVOM/VT optical observations with VHF data
  35. GRB 251025B: MASTER OT detection
  36. GRB 251025B: SVOM/C-GFT optical counterpart detection
  37. GRB 251025B: SVOM detection of a burst
  38. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  39. GRB 251025A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  40. GRB 251025A: SVOM/VT VHF optical upper limit
  41. GRB 251025A: SVOM detection of a faint burst
  42. GRB 251003A: VLA Detection
  43. GRB 251024A: Enhanced Swift-XRT position
  44. GRB 251023C: Glowbug gamma-ray detection
  45. GRB 251024A: LCOGT Optical Afterglow Detection
  46. GRB 251022A: KAIT optical observations
  47. GRB 251024A: Swift detection of a burst
  48. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  49. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  50. EP251023a: MAO/AZT-22 optical observations
  51. GRB 251023C: AstroSat CZTI detection
  52. EP251023b/GRB 251023B: JinShan optical observation
  53. GRB 251022A: Swift-XRT detection of GOTO25iym
  54. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  55. GRB 251022A: GROWTH-India Telescope optical observations
  56. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  57. EP251023a: GROWTH-India Telescope optical observations
  58. GRB 251022A: Fermi GBM Observation
  59. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  60. GRB 251023A: Glowbug gamma-ray detection
  61. GRB 251023B: Glowbug gamma-ray detection
  62. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  63. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  64. IPN triangulation of GRB 251016B
  65. EP#01709247298: Swift-XRT counterpart detection
  66. EP251023a: COLIBRÍ optical observations
  67. GRB 251013C: further SAO RAS optical observations
  68. GRB 251022A: COLIBRÍ optical observations
  69. GRB 251013C: ISON-Castelgrande observatory optical observations
  70. GRB 251022A: MASTER OT detection
  71. GRB 251022A: DDOTI Optical Detection
  72. EP251021b/GRB 251021A: SVOM/VT optical candidate
  73. GRB 251023B / MAXI J0451+122: MAXI/GSC detection
  74. EP251023a: NOT optical counterpart detection
  75. EP251023a: GSP Optical Counterpart Detection
  76. EP251023a: Einstein Probe detection of an X-ray transient
  77. GRB 251016B: Fermi GBM Detection
  78. GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
  79. EP251021b: Einstein Probe detection of a fast X-ray transient
  80. LIGO/Virgo/KAGRA S251021u: Updated Sky localization
  81. LIGO/Virgo/KAGRA S251021u: Identification of a GW compact binary merger candidate
  82. LIGO/Virgo/KAGRA S251018bi: Updated Sky localization
  83. Fermi-LAT gamma-ray observations of IceCube-251018A
  84. GRB 251017A : RAPAS follow-up observations
  85. IceCube-251018A: Upper limits from a search for additional neutrino events in IceCube
  86. GRB 251017A: COLIBRÍ optical observations of a late plateau
  87. IceCube-251018A: DDOTI Optical Upper Limit
  88. GRB 251017A: Swift-BAT refined analysis
  89. GRB 251018A: Fermi GBM Observation
  90. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  91. GRB 251018A: Swift-XRT refined Analysis
  92. GRB 251018A: Enhanced Swift-XRT position
  93. LIGO/Virgo/KAGRA S251018bi: Identification of a GW compact binary merger candidate
  94. GRB 251016A: Swift-XRT afterglow detection
  95. GRB 251017A: Swift/UVOT Detection
  96. GRB 251016A: Swift/UVOT Detection
  97. GRB 251018A: Swift/UVOT Detection
  98. GRB 251016A: VLT/FORS2 Optical Observation
  99. GRB 251017A: COLIBRÍ photometric redshift
  100. GRB 251017A: Swift-XRT refined Analysis

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