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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').
Advanced Search

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"

18488 results found.

  1. GRB 251024A: LCOGT Optical Afterglow Detection
  2. GRB 251022A: KAIT optical observations
  3. GRB 251024A: Swift detection of a burst
  4. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  5. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  6. EP251023a: MAO/AZT-22 optical observations
  7. EP251023b/GRB 251023B: JinShan optical observation
  8. GRB 251022A: Swift-XRT detection of GOTO25iym
  9. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  10. GRB 251022A: GROWTH-India Telescope optical observations
  11. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  12. EP251023a: GROWTH-India Telescope optical observations
  13. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  14. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  15. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  16. IPN triangulation of GRB 251016B
  17. EP251023a: COLIBRÍ optical observations
  18. GRB 251013C: further SAO RAS optical observations
  19. GRB 251022A: COLIBRÍ optical observations
  20. GRB 251013C: ISON-Castelgrande observatory optical observations
  21. GRB 251022A: MASTER OT detection
  22. GRB 251022A: DDOTI Optical Detection
  23. EP251021b/GRB 251021A: SVOM/VT optical candidate
  24. EP251023a: NOT optical counterpart detection
  25. EP251023a: Einstein Probe detection of an X-ray transient
  26. EP251021b: Einstein Probe detection of a fast X-ray transient
  27. GRB 250911A: MAXI/GSC detection
  28. LIGO/Virgo/KAGRA S251021u: Identification of a GW compact binary merger candidate
  29. GRB 251017A : RAPAS follow-up observations
  30. GRB 251017A: COLIBRÍ optical observations of a late plateau
  31. IceCube-251018A: DDOTI Optical Upper Limit
  32. GRB 251018A: Swift-XRT refined Analysis
  33. GRB 251018A: Enhanced Swift-XRT position
  34. LIGO/Virgo/KAGRA S251018bi: Identification of a GW compact binary merger candidate
  35. GRB 251016A: Swift-XRT afterglow detection
  36. GRB 251017A: Swift/UVOT Detection
  37. GRB 251016A: Swift/UVOT Detection
  38. GRB 251018A: Swift/UVOT Detection
  39. GRB 251016A: VLT/FORS2 Optical Observation
  40. GRB 251017A: COLIBRÍ photometric redshift
  41. GRB 251018A: TRT optical afterglow detection
  42. GRB 251018A: Swift detection of a burst with an optical counterpart
  43. GRB 251017A: J-band detection with WINTER
  44. GRB 251013C: Liverpool Telescope observations
  45. GRB 251013C: Leavitt Observatory optical photometry
  46. GRB 251017A: JinShan observations of the optical afterglow
  47. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  48. GRB 251016A: AstroSat CZTI detection of a short burst
  49. GRB 251017A: Enhanced Swift-XRT position
  50. GRB 251017A: COLIBRÍ Early Afterglow Detection
  51. GRB 251017A: Swift detection of a burst with an optical counterpart
  52. GRB 251013C: JinShan observations of the non-thermal rebrightening of the optical counterpart
  53. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) observations of a strong and late rebrightening of the optical counterpart
  54. sb25101602: Swift-XRT counterpart detection
  55. GRB 251014A: Swift-XRT observations
  56. GRB 251014B: PRIME J-band upper limit
  57. GRB 251013C: Kilonova-Catcher optical afterglow detection
  58. GRB 251013D: Swift/UVOT Observations
  59. GRB 251013C: Swift/UVOT Detection
  60. GRB 251013C: detection of a radio counterpart at 15.5GHz
  61. Swift Trigger 1404295: possible GRB 251015A
  62. GRB 251014B: Swift/UVOT Upper Limits
  63. GRB 251014B: VLT/FORS2 Optical Observation
  64. GRB 251014D: Swift/UVOT Upper Limits
  65. GRB 251014D: Swift-XRT afterglow detection
  66. GRB 251013C: MAO/AZT-22 optical observations
  67. GRB 251011B: SVOM/VT optical upper limit
  68. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) further multi-band optical observations
  69. GRB 251013C: Calapai Observatory, Massa S. Giorgio (Messina), optical observation
  70. GRB 251014D: Swift detection of a burst
  71. GRB 251014A: PRIME near-infrared upper limits
  72. GRB 251014A: VLT/FORS2 Optical Observation
  73. GRB 251013C: MarSEC, optical afterglow photometry
  74. GRB 251013C: OHP/T193 optical afterglow photometry and spectroscopy
  75. GRB 251013D: LAST optical upper limit on Swift/BAT-GUANO localization
  76. GRB 251013C: Bassano Bresciano Observatory optical observations
  77. GRB 251013C: Early and late-time optical counterpart detection by LCO
  78. GRB 251014A: DDOTI Upper Limit
  79. GRB 251013C NUTTelA-TAO / BSTI Early Measurements
  80. LIGO/Virgo/KAGRA S251014cn: Identification of a GW compact binary merger candidate
  81. GRB 251013C: ULL-ASTRO-MASTER detection of the optical afterglow with the LCO 40-cm telescope at Sutherland Observatory
  82. GRB 251013C: Asiago optical observations
  83. GRB 251013C: ABObservatory optical observations
  84. GRB 251014A: SAO RAS optical upper limit
  85. GRB 251013C: J band observations by SYSU 80cm infrared telescope
  86. GRB 251013C: EP-FXT counterpart detection
  87. GRB 251013C: AstroSat CZTI detection
  88. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) detection of the optical counterpart
  89. GRB 251013C: DDOTI detection of the optical afterglow
  90. GRB 251013C: SAO RAS optical observations
  91. GRB 251013C: LCO optical afterglow detection
  92. GRB 251013C: LAST detection of optical counterpart
  93. GRB 251013C: SVOM/VT optical observation
  94. GRB 251013C: SVOM detection of a burst
  95. GRB 251013B: SVOM/GRM observation
  96. GRB 251013A: SVOM/GRM observation
  97. GRB 251003A: Mondy optical upper limit
  98. MASTER OT J011025.98-583210.6 : SVOM/VT optical observation
  99. GRB 251011B: Swift/UVOT Upper Limits
  100. GRB 251011B: SVOM/GRM observation

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