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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"

32720 results found.

  1. GRB 251022A: SVOM/GRM observation
  2. GRB 251026B: Swift ToO observations
  3. GRB 251026A/EP251026a: Einstein Probe detection of a fast X-ray transient
  4. GRB 251027A: LCO optical upper limit
  5. GRB 251027A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  6. GRB 251017A: Mondy AZT-33IK and Koshka Zeiss-1000 optical observations
  7. GRB 251023B / EP251023b: Mondy optical upper limit
  8. GRB 251017A: INASAN-Kislovodsk optical observations
  9. GRB 251026A: Mondy optical upper limit
  10. GRB 251025B: Mondy optical observations
  11. GRB 251025B: Kilonova-Catcher optical afterglow detection
  12. Konus-Wind detection of GRB 251016A (short/hard)
  13. GRB 251025B: VLT/MUSE spectroscopic redshift z = 2.003
  14. GRB 251026B: Tentative GOTO optical counterpart candidate
  15. GRB 251025C: AstroSat CZTI detection
  16. EP251023a: Mondy optical observations
  17. GRB 251025C: CALET Gamma-Ray Burst Monitor detection
  18. GRB 251025B: MAO/AZT-22 optical observations
  19. LIGO/Virgo/KAGRA S251026bn: Updated Sky localization
  20. Fermi GRB 251026B: Global MASTER-Net observations report
  21. Fermi GRB 251025C: Global MASTER-Net observations report
  22. LIGO/Virgo/KAGRA S251026bn: Identification of a GW compact binary merger candidate
  23. GRB 251026A: Swift-XRT observations
  24. GRB 251025B: OHP/T193 optical detection
  25. GRB 251025B: J-band detection with WINTER
  26. GRB 251026A: SVOM/C-GFT upper limit
  27. IceCube-251025A: DDOTI Optical Upper Limit
  28. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  29. GRB 251025B: SVOM/VT optical bump
  30. GRB 251025B: SVOM/COLIBRÍ (FM-GFT) strong rebrightening of the optical counterpart
  31. GRB 251023A: SVOM/GRM observation
  32. GRB 251025B: ULL-ASTRO-MASTER optical counterpart detection with IAC80 telescope at Teide Observatory
  33. Konus-Wind detection of GRB 251016B
  34. GRB 251025B: GROWTH-India Telescope optical observations
  35. GRB 251024A: Swift/UVOT Upper Limits
  36. GRB 251025B: Swift-XRT afterglow detection
  37. GRB 251024A: Swift-BAT refined analysis
  38. GRB 251025A (sb25102501): stellar flare confirmed
  39. GRB 251025B: SVOM/VT optical observations with VHF data
  40. GRB 251025B: MASTER OT detection
  41. GRB 251025B: SVOM/C-GFT optical counterpart detection
  42. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  43. GRB 251025A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  44. GRB 251025A: SVOM/VT VHF optical upper limit
  45. GRB 251003A: VLA Detection
  46. GRB 251023C: Glowbug gamma-ray detection
  47. GRB 251024A: LCOGT Optical Afterglow Detection
  48. GRB 251022A: KAIT optical observations
  49. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  50. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  51. EP251023a: MAO/AZT-22 optical observations
  52. GRB 251023B: OHP/T193 optical observations
  53. EP251023a: OHP/T193 optical observations
  54. GRB 251023C: AstroSat CZTI detection
  55. EP251023b/GRB 251023B: JinShan optical observation
  56. GRB 251022A: Swift-XRT detection of GOTO25iym
  57. EP251023b: Global MASTER-Net observations report
  58. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  59. GRB 251023C: CALET Gamma-Ray Burst Monitor detection
  60. GRB 251022A: GROWTH-India Telescope optical observations
  61. EP251023a: GROWTH-India Telescope optical observations
  62. GRB 251022A: Fermi GBM Observation
  63. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  64. GRB 251023A: Glowbug gamma-ray detection
  65. GRB 251023B: Glowbug gamma-ray detection
  66. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  67. EP251023a: Global MASTER-Net observations report
  68. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  69. IPN triangulation of GRB 251016B
  70. GRB 251023B: CALET Gamma-Ray Burst Monitor detection
  71. EP#01709247298: Swift-XRT counterpart detection
  72. EP251023a: COLIBRÍ optical observations
  73. GRB 251013C: further SAO RAS optical observations
  74. EP251023a: Keck/LRIS spectroscopic redshift z=2.232
  75. GRB 251022A: COLIBRÍ optical observations
  76. GRB 251013C: ISON-Castelgrande observatory optical observations
  77. GRB 251022A: MASTER OT detection
  78. GRB 251022A: DDOTI Optical Detection
  79. EP251021b/GRB 251021A: SVOM/VT optical candidate
  80. EP251023a: NOT optical counterpart detection
  81. Fermi GRB 251023A: Global MASTER-Net observations report
  82. EP251023a: GSP Optical Counterpart Detection
  83. EP251023a: Einstein Probe detection of an X-ray transient
  84. GRB 251022A: GOTO optical counterpart detection
  85. GRB 251022A: Fermi-LAT detection
  86. GRB 251022A: Tiled Swift observations
  87. GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
  88. EP251021b: BOOTES-7 optical upper limit
  89. GRB 250911A: MAXI/GSC detection
  90. LIGO/Virgo/KAGRA S251021u: Updated Sky localization
  91. GRB 251016A: SVOM/ECLAIRs refined analysis
  92. LIGO/Virgo/KAGRA S251021u: Identification of a GW compact binary merger candidate
  93. LIGO/Virgo/KAGRA S251018bi: Updated Sky localization
  94. Fermi-LAT gamma-ray observations of IceCube-251018A
  95. GRB 251017A : RAPAS follow-up observations
  96. IceCube-251018A: Upper limits from a search for additional neutrino events in IceCube
  97. GRB 251017A: COLIBRÍ optical observations of a late plateau
  98. IceCube-251018A: DDOTI Optical Upper Limit
  99. GRB 251017A: Swift-BAT refined analysis
  100. GRB 251016A: Fermi GBM Observation

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