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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"

752 results found.

  1. GRB 240415A: Prompt Swift-XRT observations
  2. IPN triangulation of GRB 240410A
  3. X-ray transient EP240315a: second epoch e-MERLIN radio observations
  4. Fermi trigger No 731303574: Global MASTER-Net observations report
  5. IPN triangulation of GRB 240303B
  6. IPN triangulation of GRB 240125A (short)
  7. IPN triangulation of GRB 240123C (short)
  8. IPN triangulation of GRB 240112A (long)
  9. LIGO/Virgo/KAGRA S240107b: Identification of a GW compact binary merger candidate
  10. LIGO/Virgo/KAGRA S231213ap: Identification of a GW compact binary merger candidate
  11. IPN triangulation of GRB 231129C
  12. IPN triangulation of GRB 231205A
  13. LIGO/Virgo/KAGRA S231206cc: Identification of a GW compact binary merger candidate
  14. LIGO/Virgo/KAGRA S231206ca: Identification of a GW compact binary merger candidate
  15. GRB 231205B: Ondrejov D50 optical upper limit
  16. LIGO/Virgo/KAGRA S231129ac: Identification of a GW compact binary merger candidate
  17. LIGO/Virgo/KAGRA S231127cg: Identification of a GW compact binary merger candidate
  18. Konus-Wind detection of GRB 231020A
  19. 231118A: Swift-UVOT Detection
  20. LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
  21. GRB 231118A: Las Cumbres optical detection
  22. LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
  23. LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
  24. LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
  25. GRB 231117A: Swift detection of a bright short burst
  26. GRB 231115A: Non-detection in low-latency of gravitational waves with LIGO/Virgo/KAGRA
  27. LIGO/Virgo/KAGRA S231114n: Identification of a GW compact binary merger candidate
  28. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  29. LIGO/Virgo/KAGRA S231113bw: Identification of a GW compact binary merger candidate
  30. LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
  31. LIGO/Virgo/KAGRA S231108u: Identification of a GW compact binary merger candidate
  32. LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
  33. LIGO/Virgo/KAGRA S231102w: Identification of a GW compact binary merger candidate
  34. IPN triangulation of GRB 231020A
  35. LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
  36. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  37. GRB 230911C: ATCA detection of possible radio counterpart
  38. GRB 231017A: Las Cumbres optical upper limit
  39. LIGO/Virgo/KAGRA S231008ap: Identification of a GW compact binary merger candidate
  40. LIGO/Virgo/KAGRA S231005ah: Identification of a GW compact binary merger candidate
  41. LIGO/Virgo/KAGRA S231001aq: Identification of a GW compact binary merger candidate
  42. LIGO/Virgo/KAGRA S230928cb: Identification of a GW compact binary merger candidate
  43. LIGO/Virgo/KAGRA S230927be: Identification of a GW compact binary merger candidate
  44. LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
  45. LIGO/Virgo/KAGRA S230924an: Identification of a GW compact binary merger candidate
  46. IPN triangulation of GRB 230919A (short)
  47. LIGO/Virgo/KAGRA S230920al: Identification of a GW compact binary merger candidate
  48. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  49. LIGO/Virgo/KAGRA S230914ak: Identification of a GW compact binary merger candidate
  50. IPN triangulation of GRB 230911D (long)
  51. IPN triangulation of GRB 230906A (short)
  52. LIGO/Virgo/KAGRA S230904n: Identification of a GW compact binary merger candidate
  53. LIGO/Virgo/KAGRA S230831e: Identification of a GW compact binary merger candidate
  54. LIGO/Virgo/KAGRA S230814ah: Updated Sky localization
  55. LIGO/Virgo/KAGRA S230824r: Identification of a GW compact binary merger candidate
  56. GRB 230812B: AstroSat LAXPC detection
  57. LIGO/Virgo/KAGRA S230820bq: Identification of a GW compact binary merger candidate
  58. LIGO/Virgo/KAGRA S230819ax: Identification of a GW compact binary merger candidate
  59. Swift GRB230818.98: Global MASTER-Net observations report
  60. IPN triangulation of GRB 230815B
  61. LIGO/Virgo/KAGRA S230814r: Identification of a GW compact binary merger candidate
  62. LIGO/Virgo/KAGRA S230811n: Identification of a GW compact binary merger candidate
  63. LIGO/Virgo/KAGRA S230807f: Identification of a GW compact binary merger candidate
  64. LIGO/Virgo/KAGRA S230806ak: Identification of a GW compact binary merger candidate
  65. LIGO/Virgo/KAGRA S230805x: Identification of a GW compact binary merger candidate
  66. IPN triangulation of GRB 230803A
  67. LIGO/Virgo/KAGRA S230731an: Identification of a GW compact binary merger candidate
  68. GRB 230723B: MITSuME Ishigaki optical observation
  69. IPN triangulation of GRB 230723A (short)
  70. LIGO/Virgo/KAGRA S230723ac: Identification of a GW compact binary merger candidate
  71. IPN triangulation of GRB 230715D
  72. LIGO/Virgo/KAGRA S230709bi: Identification of a GW compact binary merger candidate
  73. LIGO/Virgo/KAGRA S230708cf: Identification of a GW compact binary merger candidate
  74. LIGO/Virgo/KAGRA S230707ai: Identification of a GW compact binary merger candidate
  75. LIGO/Virgo/KAGRA S230706ah: Identification of a GW compact binary merger candidate
  76. LIGO/Virgo/KAGRA S230702an: Identification of a GW compact binary merger candidate
  77. LIGO/Virgo/KAGRA S230630bq: Identification of a GW compact binary merger candidate
  78. IPN triangulation of GRB 230625B (ultra-long)
  79. LIGO/Virgo/KAGRA S230628ax: Identification of a GW compact binary merger candidate
  80. LIGO/Virgo/KAGRA S230627c: Identification of a GW compact binary merger candidate
  81. LIGO/Virgo/KAGRA S230624av: Identification of a GW compact binary merger candidate
  82. GRB 230622A: Swift-XRT refined Analysis
  83. IPN triangulation of GRB 230616A (short)
  84. GRB 230614C: AstroSat CZTI detection
  85. LIGO/Virgo S230611l: Global MASTER-Net observations report
  86. LIGO/Virgo/KAGRA S230609u: Identification of a GW compact binary merger candidate
  87. LIGO/Virgo/KAGRA S230608as: Identification of a GW compact binary merger candidate
  88. LIGO/Virgo/KAGRA S230606d: Identification of a GW compact binary merger candidate
  89. LIGO/Virgo/KAGRA S230605o: Identification of a GW compact binary merger candidate
  90. LIGO/Virgo/KAGRA S230601bf: Identification of a GW compact binary merger candidate
  91. IPN triangulation of GRB 230430A (short)
  92. IPN triangulation of GRB 230418A (short)
  93. GRB 230405B: Fermi GBM Observation
  94. IPN triangulation of GRB 230304B
  95. IPN triangulation of GRB 230308A (short/bright)
  96. Further improved IPN localization for GRB 230307A
  97. Swift GRB230311.84: Global MASTER-Net observations report
  98. Improved IPN localization for GRB 230307A
  99. IPN triangulation of GRB 230307A (long/very bright)
  100. Konus-Wind detection of GRB 230217A

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