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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"

28047 results found.

  1. GRB231111A: Optical follow-up observations with Mephisto
  2. GRB 231111A: GMG observation (correction)
  3. GRB 231111A: GMG observation upper limit
  4. GRB 231106B: GRBAlpha detection
  5. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  6. GRB 231111A: Swift-XRT refined Analysis
  7. GRB 231111A: Mondy optical observations
  8. GRB 231111A: Enhanced Swift-XRT position
  9. GRB 231110A: SAO RAS optical observations
  10. GRB231111A: GIT confirmation of the optical afterglow
  11. GRB 231111A: Nanshan/HMT optical observations
  12. GRB 231111A: Swift detection of a burst with an optical counterpart
  13. Swift GRB231111.60: Global MASTER-Net observations report
  14. GRB231110A: WFST Observation and upper limits
  15. GRB 231110A: Swift detection of a burst
  16. LIGO/Virgo/KAGRA S231110g: Updated Sky localization
  17. LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
  18. LIGO/Virgo/KAGRA S231108u: Updated Sky localization
  19. LIGO/Virgo/KAGRA O4 Landscape
  20. LIGO/Virgo/KAGRA S231108u: Identification of a GW compact binary merger candidate
  21. GRB 231104A: Swift-BAT refined analysis
  22. LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO
  23. GRB 231104A: NuSTAR Observation of the prompt emission
  24. GRB 231104A: 3.6m DOT optical upper limit
  25. IceCube-231103A: Upper limits from a search for additional neutrino events in IceCube
  26. LIGO/Virgo/KAGRA S231106y: one counterpart neutrino candidate from IceCube neutrino searches
  27. Fermi-LAT gamma-ray observations of IceCube-231103A
  28. GRB 231104A: NOT upper limit
  29. GRB 231104A: Fermi GBM Observation
  30. Fermi GRB 231103A: Global MASTER-Net observations report
  31. LIGO/Virgo/KAGRA S231104ac: Updated Sky localization
  32. GRB 231104A: AKO Upper Limit
  33. GRB 231104A: AstroSat CZTI detection
  34. GRB 231104A: Swift-XRT refined Analysis
  35. GRB 231104A: Fermi-LAT detection
  36. LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
  37. GRB 231104A: Swift/UVOT Upper Limits
  38. GRB 231104A: Enhanced Swift-XRT position
  39. GRB231104A: LCOGT Optical Upper Limits
  40. GRB 231104A: Swift detection of a bright burst
  41. Fermi-LAT gamma-ray observations of IceCube-231027A
  42. LIGO/Virgo/KAGRA S231102w: Updated Sky localization
  43. GRB 231101A: Glowbug gamma-ray detection
  44. LIGO/Virgo/KAGRA S231102w: Identification of a GW compact binary merger candidate
  45. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  46. GRB 231101A: Fermi GBM Final Real-time Localization
  47. GRB 231028B: VZLUSAT-2 detection
  48. GRB 231030B: Fermi GBM Detection
  49. IPN triangulation of GRB 231020A
  50. GRB 231030B: BALROG localization (Fermi Trigger 720388704 / GRB 231030832)
  51. GRB 231028A: Swift-BAT refined analysis
  52. IceCube-231027A: Upper limits from a search for additional neutrino events in IceCube
  53. LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
  54. GRB 231024A: AKO Optical Counterpart Candidate
  55. LIGO/Virgo/KAGRA S231029y: One counterpart neutrino candidate from IceCube neutrino searches
  56. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  57. LIGO/Virgo/KAGRA S231029y: Identification of a GW compact binary merger candidate
  58. GRB 231028A: AstroSat CZTI detection
  59. GRB 231028A: Glowbug gamma-ray detection
  60. GRB 231028A: Fermi GBM Detection
  61. LIGO/Virgo/KAGRA S231028bg: Updated Sky localization
  62. LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
  63. GRB 231028A: Swift detection of a burst
  64. GRB 231019A: Glowbug gamma-ray detection
  65. GRB 231025A: Fermi GBM Observation
  66. GRB 231024A: Fermi GBM Observation
  67. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  68. GRB 231020B: AstroSat CZTI detection
  69. GRB 231024A: GOTO optical counterpart candidate
  70. LIGO/Virgo/KAGRA S231025a: two counterpart neutrino candidates from IceCube neutrino searches
  71. The photometry of the transient in Messier 31 field: GMG observation
  72. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  73. LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
  74. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  75. LIGO/Virgo/KAGRA S231020bw: Updated Sky localization
  76. GRB 231020A: Fermi GBM Detection
  77. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  78. GRB 231019A: VZLUSAT-2 detection
  79. GRB 231018A: VZLUSAT-2 detection
  80. GRB 231020B: BALROG localization (Fermi Trigger 719530557 / GRB 231020900)
  81. LIGO/Virgo/KAGRA S231020ba: Updated Sky localization and EM Bright Classification
  82. GRB 231020A: BALROG localization (Fermi Trigger / GRB 231020790)
  83. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  84. GRB 231015A: NuSTAR Detection of Prompt Emission
  85. LIGO/Virgo/KAGRA S231020bw: Identification of a GW compact binary merger candidate
  86. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  87. GRB 231017A: 1.3m DFOT Optical upper limit
  88. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  89. IceCube-231004A: Upper limits from Fermi-GBM Observations
  90. GRB 231018A: Glowbug gamma-ray detection
  91. IPN triangulation of GRB 231018A
  92. GRB 231017A: Swift/UVOT Upper Limit
  93. GRB 230911C: ATCA detection of possible radio counterpart
  94. GRB 231017A: JinShan optical upper limit
  95. GRB 231018A: GROWTH-India Follow-Up of a Fermi Long GRB
  96. LIGO/Virgo/KAGRA S231018cb: One counterpart neutrino candidate event from an IceCube neutrino search
  97. IC231004A: Classification of AT2023uqf/ZTF23abidzvf as a rapidly-evolving supernova with CSM interaction
  98. GRB 231017A: Las Cumbres optical upper limit
  99. GRB 231015A: Glowbug gamma-ray detection
  100. GRB 231017A: LCOGT Optical Upper Limits

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