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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"

32533 results found.

  1. IceCube-231103A: No candidates from the Zwicky Transient Facility
  2. LIGO/Virgo/KAGRA S231108u: Updated Sky localization
  3. Fermi GRB 231108A: Global MASTER-Net observations report
  4. LIGO/Virgo/KAGRA S231108u: Identification of a GW compact binary merger candidate
  5. GRB 231106A: AstroSat CZTI detection
  6. GRB 231106A: CALET Gamma-Ray Burst Monitor detection
  7. GRB 231104A: Swift-BAT refined analysis
  8. Fermi GRB 231106A: Global MASTER-Net observations report
  9. GRB 231104A: Wendelstein Optical/Infrared Observations
  10. GRB 231104A: NuSTAR Observation of the prompt emission
  11. GRB 231104A: 3.6m DOT optical upper limit
  12. IceCube-231103A: Upper limits from a search for additional neutrino events in IceCube
  13. Fermi-LAT gamma-ray observations of IceCube-231103A
  14. GRB 231104A: NOT upper limit
  15. GRB 231104A: Fermi GBM Observation
  16. Fermi GRB 231103A: Global MASTER-Net observations report
  17. LIGO/Virgo/KAGRA S231104ac: Updated Sky localization
  18. GRB 231104A: AKO Upper Limit
  19. GRB 231104A: AstroSat CZTI detection
  20. GRB 231104A: Fermi-LAT detection
  21. LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
  22. GRB 231104A: Swift/UVOT Upper Limits
  23. GRB231104A: LCOGT Optical Upper Limits
  24. Fermi-LAT gamma-ray observations of IceCube-231027A
  25. LIGO/Virgo/KAGRA S231102w: Updated Sky localization
  26. GRB 231101A: Glowbug gamma-ray detection
  27. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  28. LIGO/Virgo/KAGRA S231102w: Identification of a GW compact binary merger candidate
  29. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  30. GRB 231030B: GRBAlpha detection
  31. GRB 231030B: Fermi GBM Detection
  32. GRB 231030B: AstroSat CZTI detection
  33. Fermi GRB 231030B: Global MASTER-Net observations report
  34. IPN triangulation of GRB 231020A
  35. GRB 231028A: Swift-BAT refined analysis
  36. IceCube-231027A: Upper limits from a search for additional neutrino events in IceCube
  37. GRB 231024A: AKO Optical Counterpart Candidate
  38. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  39. Fermi GRB 231030A: Global MASTER-Net observations report
  40. LIGO/Virgo/KAGRA S231029y: Identification of a GW compact binary merger candidate
  41. GRID detection of GRB 231020A
  42. GRB 231028A: AstroSat CZTI detection
  43. GRB 231028A: Glowbug gamma-ray detection
  44. GRB 231028A: Fermi GBM Detection
  45. Swift GRB 231028A: Global MASTER-Net observations report
  46. LIGO/Virgo/KAGRA S231028bg: Updated Sky localization
  47. LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
  48. GRB 231028A: Swift detection of a burst
  49. GRB 231019A: Glowbug gamma-ray detection
  50. IC231004A: GRANDMA observations of AT2023uqf/ZTF23abidzvf candidate
  51. GRB 231025A: Fermi GBM Observation
  52. GRB 231024A: Fermi GBM Observation
  53. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  54. GRB 231024A: X-shooter spectroscopy of AT2023vuc/GOTO23baj reveals a young supernova with flash ionisation features
  55. GRB 231024A: LCOGT and ZTF detections of the GOTO optical counterpart candidate
  56. GRB 231020A: AstroSat CZTI detection
  57. GRB 231020B: AstroSat CZTI detection
  58. GRB 231024A: GOTO optical counterpart candidate
  59. The photometry of the transient in Messier 31 field: GMG observation
  60. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  61. LIGO/Virgo/KAGRA S231020bw: Updated Sky localization
  62. GRB 231020A: Fermi GBM Detection
  63. GRID detection of GRB 231004A
  64. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  65. GRB 231019A: VZLUSAT-2 detection
  66. GRB 231018A: VZLUSAT-2 detection
  67. LIGO/Virgo/KAGRA S231020ba: Updated Sky localization and EM Bright Classification
  68. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  69. GRB 231015A: NuSTAR Detection of Prompt Emission
  70. Fermi GRB 231020A: Global MASTER-Net observations report
  71. LIGO/Virgo/KAGRA S231020bw: Identification of a GW compact binary merger candidate
  72. GRB 231012A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  73. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  74. GRB 231017A: 1.3m DFOT Optical upper limit
  75. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  76. IceCube-231004A: Upper limits from Fermi-GBM Observations
  77. GRB 231018A: GRBAlpha detection
  78. GRB 231018A: CALET Gamma-Ray Burst Monitor detection
  79. Fermi GRB 231019A: Global MASTER-Net observations report
  80. GRB 231018A: Glowbug gamma-ray detection
  81. Konus-Wind detection of GRB 231018A
  82. IPN triangulation of GRB 231018A
  83. GRB 231017A: Swift/UVOT Upper Limit
  84. GRB 230911C: ATCA detection of possible radio counterpart
  85. GRB 231017A: GOTO optical upper limits
  86. GRB 231017A: JinShan optical upper limit
  87. GRB 231018A: GROWTH-India Follow-Up of a Fermi Long GRB
  88. IC231004A: Classification of AT2023uqf/ZTF23abidzvf as a rapidly-evolving supernova with CSM interaction
  89. GRB 231017A: Las Cumbres optical upper limit
  90. GRB 231015A: Glowbug gamma-ray detection
  91. GRB 231017A: LCOGT Optical Upper Limits
  92. GRB231017A: GROWTH-India upper limits on the optical afterglow
  93. GRB 231015A: AstroSat CZTI detection
  94. GRB 231018A: Fermi GBM Detection
  95. GRB 231017A: Fermi GBM Detection
  96. GRB 231017A: Swift-XRT observations
  97. GRB 231012B may not be a GRB
  98. GRB 231017A: Swift ToO observations
  99. GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
  100. Fermi-LAT gamma-ray observations of IceCube-231014A

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