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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"

4255 results found.

  1. GRB 231129A: JinShan optical upper limit
  2. GRB 231129C: GRBAlpha detection
  3. GRB 231129C: Glowbug gamma-ray detection
  4. GRB 231129A: optical upper limit in Mondy observatory
  5. GRB 231129C: AstroSat CZTI detection
  6. GRB 231129C: CALET Gamma-Ray Burst Monitor detection
  7. GRB 231129C: Fermi GBM Observation of a very bright GRB
  8. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  9. GRB 231129C: MAXI/GSC detection
  10. GRB 231129C: BALROG localization (Fermi Trigger / GRB 231129799)
  11. GRB 231129C: Fermi GBM detection of a very bright burst
  12. GRB 231129C: Fermi GBM Final Real-time Localization
  13. Fermi trigger No 722977823: Global MASTER-Net observations report
  14. GRB 231129B: MAXI/GSC detection
  15. Integral GRB231129.21: Global MASTER-Net observations report
  16. LIGO/Virgo/KAGRA S231129ac: Identification of a GW compact binary merger candidate
  17. Fermi trigger No 722507896: Global MASTER-Net observations report
  18. Fermi trigger No 722462310: Global MASTER-Net observations report
  19. Fermi trigger No 722349867: Global MASTER-Net observations report
  20. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  21. GRB 231118A: Fermi GBM Final Real-time Localization
  22. LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
  23. GRB 231117A: AKO Optical Upper Limit
  24. Swift GRB 231117A: Global MASTER-Net observations report
  25. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  26. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  27. GRB 231115A: archival HST observations
  28. GECAM-B observation of a short burst from SGR J1555-5402
  29. SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
  30. GRB 231111A: GMG observation (correction)
  31. GRB 231111A: GMG observation upper limit
  32. Fermi GRB 231108A: Global MASTER-Net observations report
  33. Fermi GRB 231106A: Global MASTER-Net observations report
  34. GRB 231104A: 3.6m DOT optical upper limit
  35. Fermi GRB 231103A: Global MASTER-Net observations report
  36. GRB 231104A: Fermi-LAT detection
  37. LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
  38. IceCube Alert 231103.39: Global MASTER-Net observations report
  39. Fermi trigger No 720498201: Global MASTER-Net observations report
  40. GRB 231024A: AKO Optical Counterpart Candidate
  41. Fermi GRB 231030A: Global MASTER-Net observations report
  42. LIGO/Virgo/KAGRA S231029y: One counterpart neutrino candidate from IceCube neutrino searches
  43. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S231029y: Identification of a GW compact binary merger candidate
  45. LIGO/Virgo/KAGRA S231029k: Global MASTER-Net observations report
  46. Fermi trigger No 720224759: Global MASTER-Net observations report
  47. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  48. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  49. IC231004A: GRANDMA observations of AT2023uqf/ZTF23abidzvf candidate
  50. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  51. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  52. Fermi GRB 231019A: Global MASTER-Net observations report
  53. LIGO/Virgo/KAGRA S231014r: Identification of a GW compact binary merger candidate
  54. GRB 230827B: 10.4m GTC spectroscopic redshift
  55. LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
  56. LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
  57. IPN triangulation of GRB 230919A (short)
  58. transient AT2023sva: imaging and spectroscopic observations from MISTRAL at Observatoire de Haute-Provence
  59. LIGO/Virgo/KAGRA S230920al: Identification of a GW compact binary merger candidate
  60. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  61. IceCube-230914A: Upper limits from a search for additional neutrino events in IceCube
  62. GRB 230911A: Swift-XRT afterglow detection
  63. Fermi trigger No 716449174: Global MASTER-Net observations report
  64. IceCube Alert 230914.22: Global MASTER-Net observations report
  65. GRB 230911A: GOTO optical counterpart candidate
  66. GRB 230906A: Chandra detection of the X-ray afterglow
  67. GRB 230903A: VLT/X-shooter optical observations
  68. GRB 230904C: Fermi GBM Final Localization
  69. Fermi GRB 230903A: Global MASTER-Net observations report
  70. GRB 230904B is not a GRB
  71. GRB 230904B: BALROG localization (Fermi Trigger 715526984 / GRB 230904562)
  72. GRB 230828A: AstroSat CZTI detection
  73. GRB 230828A: GRBAlpha detection
  74. Swift Trigger 1188089 is not a GRB
  75. Fermi GRB 230827A: Global MASTER-Net observations report
  76. GRB 230824A: AKO Photometric Follow-up Observations
  77. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  78. GRB 230818B: VZLUSAT-2 detection
  79. LIGO/Virgo/KAGRA S230820bq: Identification of a GW compact binary merger candidate
  80. GRB 230818A: SAO RAS Zeiss-1000 observations
  81. Fermi GRB 230818A: Global MASTER-Net observations report
  82. GRB 230818A: Swift detection of a burst
  83. Fermi GRB 230817A: Global MASTER-Net observations report
  84. GRB 230816A: TShAO and Assy optical observations
  85. GRB 230816A: SAO RAS optical observations
  86. IPN triangulation of GRB 230815B
  87. GRB 230812B: Fermi-LAT detection
  88. GRB 230812B: Fermi GBM Observation of a very bright burst
  89. LAT GRB230812.79: Global MASTER-Net observations report
  90. GRB 230812B: Fermi GBM detection of an extremely bright GRB
  91. LIGO/Virgo/KAGRA S230802aq: AstroSat CZTI non-detection and upper limits
  92. IceCube-230724A: JCMT/SCUBA-2 submm observations
  93. LIGO/Virgo/KAGRA S230731an: AstroSat CZTI non-detection and upper limits
  94. LIGO/Virgo/KAGRA S230729z: Identification of a GW compact binary merger candidate
  95. LIGO/Virgo/KAGRA S230726a: Identification of a GW compact binary merger candidate
  96. IceCube Alert 230724.08: Global MASTER-Net observations report
  97. GRB 230724A: Fermi GBM Final Real-time Localization
  98. Fermi trigger No 711805358: Global MASTER-Net observations report
  99. Fermi GRB 230723A: Global MASTER-Net observations report
  100. GRB 230707A: Fermi GBM Detection

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