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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').
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"

3821 results found.

  1. Fermi GRB 231103A: Global MASTER-Net observations report
  2. GRB 231104A: Fermi-LAT detection
  3. LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
  4. IceCube Alert 231103.39: Global MASTER-Net observations report
  5. Fermi trigger No 720498201: Global MASTER-Net observations report
  6. GRB 231024A: AKO Optical Counterpart Candidate
  7. Fermi GRB 231030A: Global MASTER-Net observations report
  8. LIGO/Virgo/KAGRA S231029y: One counterpart neutrino candidate from IceCube neutrino searches
  9. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  10. LIGO/Virgo/KAGRA S231029y: Identification of a GW compact binary merger candidate
  11. LIGO/Virgo/KAGRA S231029k: Global MASTER-Net observations report
  12. Fermi trigger No 720224759: Global MASTER-Net observations report
  13. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  14. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  15. IC231004A: GRANDMA observations of AT2023uqf/ZTF23abidzvf candidate
  16. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  17. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  18. Fermi GRB 231019A: Global MASTER-Net observations report
  19. LIGO/Virgo/KAGRA S231014r: Identification of a GW compact binary merger candidate
  20. GRB 230827B: 10.4m GTC spectroscopic redshift
  21. LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
  22. LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
  23. IPN triangulation of GRB 230919A (short)
  24. transient AT2023sva: imaging and spectroscopic observations from MISTRAL at Observatoire de Haute-Provence
  25. LIGO/Virgo/KAGRA S230920al: Identification of a GW compact binary merger candidate
  26. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  27. IceCube-230914A: Upper limits from a search for additional neutrino events in IceCube
  28. GRB 230911A: Swift-XRT afterglow detection
  29. Fermi trigger No 716449174: Global MASTER-Net observations report
  30. IceCube Alert 230914.22: Global MASTER-Net observations report
  31. GRB 230911A: GOTO optical counterpart candidate
  32. GRB 230906A: Chandra detection of the X-ray afterglow
  33. GRB 230903A: VLT/X-shooter optical observations
  34. GRB 230904C: Fermi GBM Final Localization
  35. Fermi GRB 230903A: Global MASTER-Net observations report
  36. GRB 230904B is not a GRB
  37. GRB 230904B: BALROG localization (Fermi Trigger 715526984 / GRB 230904562)
  38. GRB 230828A: AstroSat CZTI detection
  39. GRB 230828A: GRBAlpha detection
  40. Swift Trigger 1188089 is not a GRB
  41. Fermi GRB 230827A: Global MASTER-Net observations report
  42. GRB 230824A: AKO Photometric Follow-up Observations
  43. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  44. GRB 230818B: VZLUSAT-2 detection
  45. LIGO/Virgo/KAGRA S230820bq: Identification of a GW compact binary merger candidate
  46. GRB 230818A: SAO RAS Zeiss-1000 observations
  47. Fermi GRB 230818A: Global MASTER-Net observations report
  48. GRB 230818A: Swift detection of a burst
  49. Fermi GRB 230817A: Global MASTER-Net observations report
  50. GRB 230816A: TShAO and Assy optical observations
  51. GRB 230816A: SAO RAS optical observations
  52. IPN triangulation of GRB 230815B
  53. GRB 230812B: Fermi-LAT detection
  54. GRB 230812B: Fermi GBM Observation of a very bright burst
  55. LAT GRB230812.79: Global MASTER-Net observations report
  56. GRB 230812B: Fermi GBM detection of an extremely bright GRB
  57. LIGO/Virgo/KAGRA S230802aq: AstroSat CZTI non-detection and upper limits
  58. IceCube-230724A: JCMT/SCUBA-2 submm observations
  59. LIGO/Virgo/KAGRA S230731an: AstroSat CZTI non-detection and upper limits
  60. LIGO/Virgo/KAGRA S230729z: Identification of a GW compact binary merger candidate
  61. LIGO/Virgo/KAGRA S230726a: Identification of a GW compact binary merger candidate
  62. IceCube Alert 230724.08: Global MASTER-Net observations report
  63. GRB 230724A: Fermi GBM Final Real-time Localization
  64. Fermi trigger No 711805358: Global MASTER-Net observations report
  65. Fermi GRB 230723A: Global MASTER-Net observations report
  66. GRB 230707A: Fermi GBM Detection
  67. Fermi GRB 230707A: Global MASTER-Net observations report
  68. Fermi trigger No 710117592: Global MASTER-Net observations report
  69. GRB 230628E: ATCA rapid radio follow-up
  70. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  71. GRB 230628E - VLT spectroscopic observations
  72. Fermi GRB 230628C: Global MASTER-Net observations report
  73. Fermi GRB 230628D: Global MASTER-Net observations report
  74. GRB 230628E: Swift detection of a burst
  75. GRB 230626A: GRBAlpha detection
  76. GRB 230623A: MAXI/GSC detection
  77. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  78. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  79. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  80. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  81. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  82. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  83. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  84. LIGO/Virgo S230619i: Global MASTER-Net observations report
  85. LIGO/Virgo S230618aq: Global MASTER-Net observations report
  86. LIGO/Virgo S230618y: Global MASTER-Net observations report
  87. LIGO/Virgo S230618s: Global MASTER-Net observations report
  88. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  89. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  90. LIGO/Virgo S230618k: Global MASTER-Net observations report
  91. LIGO/Virgo S230617bc: Global MASTER-Net observations report
  92. LIGO/Virgo S230617aq: Global MASTER-Net observations report
  93. LIGO/Virgo S230617aj: Global MASTER-Net observations report
  94. GRB 230616A: AstroSat CZTI detection
  95. LIGO/Virgo/KAGRA S230529ay: Upper limits from a two-week IceCube neutrino search
  96. LIGO/Virgo S230615be: Global MASTER-Net observations report
  97. LIGO/Virgo S230608aw: Global MASTER-Net observations report
  98. LIGO/Virgo S230609a: Global MASTER-Net observations report
  99. LIGO/Virgo S230608ah: Global MASTER-Net observations report
  100. GRB 230606A: Enhanced Swift-XRT position

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