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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"

32540 results found.

  1. GRB231111A: YAHPT Observations
  2. GRB231111A: GIT confirmation of the optical afterglow
  3. GRB 231111A: MASTER OT earlier detection
  4. GRB 231111A: Nanshan/HMT optical observations
  5. GRB231110A: WFST Observation and upper limits
  6. LIGO/Virgo/KAGRA S231110g: Updated Sky localization
  7. LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
  8. IceCube-231103A: No candidates from the Zwicky Transient Facility
  9. LIGO/Virgo/KAGRA S231108u: Updated Sky localization
  10. Fermi GRB 231108A: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S231108u: Identification of a GW compact binary merger candidate
  12. GRB 231106A: AstroSat CZTI detection
  13. GRB 231106A: CALET Gamma-Ray Burst Monitor detection
  14. GRB 231104A: Swift-BAT refined analysis
  15. Fermi GRB 231106A: Global MASTER-Net observations report
  16. GRB 231104A: Wendelstein Optical/Infrared Observations
  17. GRB 231104A: NuSTAR Observation of the prompt emission
  18. GRB 231104A: 3.6m DOT optical upper limit
  19. IceCube-231103A: Upper limits from a search for additional neutrino events in IceCube
  20. Fermi-LAT gamma-ray observations of IceCube-231103A
  21. GRB 231104A: NOT upper limit
  22. GRB 231104A: Fermi GBM Observation
  23. Fermi GRB 231103A: Global MASTER-Net observations report
  24. LIGO/Virgo/KAGRA S231104ac: Updated Sky localization
  25. GRB 231104A: AKO Upper Limit
  26. GRB 231104A: AstroSat CZTI detection
  27. GRB 231104A: Fermi-LAT detection
  28. LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
  29. GRB 231104A: Swift/UVOT Upper Limits
  30. GRB231104A: LCOGT Optical Upper Limits
  31. Fermi-LAT gamma-ray observations of IceCube-231027A
  32. LIGO/Virgo/KAGRA S231102w: Updated Sky localization
  33. GRB 231101A: Glowbug gamma-ray detection
  34. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  35. LIGO/Virgo/KAGRA S231102w: Identification of a GW compact binary merger candidate
  36. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  37. GRB 231030B: GRBAlpha detection
  38. GRB 231030B: Fermi GBM Detection
  39. GRB 231030B: AstroSat CZTI detection
  40. Fermi GRB 231030B: Global MASTER-Net observations report
  41. IPN triangulation of GRB 231020A
  42. GRB 231028A: Swift-BAT refined analysis
  43. IceCube-231027A: Upper limits from a search for additional neutrino events in IceCube
  44. GRB 231024A: AKO Optical Counterpart Candidate
  45. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  46. Fermi GRB 231030A: Global MASTER-Net observations report
  47. LIGO/Virgo/KAGRA S231029y: Identification of a GW compact binary merger candidate
  48. GRID detection of GRB 231020A
  49. GRB 231028A: AstroSat CZTI detection
  50. GRB 231028A: Glowbug gamma-ray detection
  51. GRB 231028A: Fermi GBM Detection
  52. Swift GRB 231028A: Global MASTER-Net observations report
  53. LIGO/Virgo/KAGRA S231028bg: Updated Sky localization
  54. LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
  55. GRB 231028A: Swift detection of a burst
  56. GRB 231019A: Glowbug gamma-ray detection
  57. IC231004A: GRANDMA observations of AT2023uqf/ZTF23abidzvf candidate
  58. GRB 231025A: Fermi GBM Observation
  59. GRB 231024A: Fermi GBM Observation
  60. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  61. GRB 231024A: X-shooter spectroscopy of AT2023vuc/GOTO23baj reveals a young supernova with flash ionisation features
  62. GRB 231024A: LCOGT and ZTF detections of the GOTO optical counterpart candidate
  63. GRB 231020A: AstroSat CZTI detection
  64. GRB 231020B: AstroSat CZTI detection
  65. GRB 231024A: GOTO optical counterpart candidate
  66. The photometry of the transient in Messier 31 field: GMG observation
  67. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  68. LIGO/Virgo/KAGRA S231020bw: Updated Sky localization
  69. GRB 231020A: Fermi GBM Detection
  70. GRID detection of GRB 231004A
  71. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  72. GRB 231019A: VZLUSAT-2 detection
  73. GRB 231018A: VZLUSAT-2 detection
  74. LIGO/Virgo/KAGRA S231020ba: Updated Sky localization and EM Bright Classification
  75. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  76. GRB 231015A: NuSTAR Detection of Prompt Emission
  77. Fermi GRB 231020A: Global MASTER-Net observations report
  78. LIGO/Virgo/KAGRA S231020bw: Identification of a GW compact binary merger candidate
  79. GRB 231012A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  80. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  81. GRB 231017A: 1.3m DFOT Optical upper limit
  82. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  83. IceCube-231004A: Upper limits from Fermi-GBM Observations
  84. GRB 231018A: GRBAlpha detection
  85. GRB 231018A: CALET Gamma-Ray Burst Monitor detection
  86. Fermi GRB 231019A: Global MASTER-Net observations report
  87. GRB 231018A: Glowbug gamma-ray detection
  88. Konus-Wind detection of GRB 231018A
  89. IPN triangulation of GRB 231018A
  90. GRB 231017A: Swift/UVOT Upper Limit
  91. GRB 230911C: ATCA detection of possible radio counterpart
  92. GRB 231017A: GOTO optical upper limits
  93. GRB 231017A: JinShan optical upper limit
  94. GRB 231018A: GROWTH-India Follow-Up of a Fermi Long GRB
  95. IC231004A: Classification of AT2023uqf/ZTF23abidzvf as a rapidly-evolving supernova with CSM interaction
  96. GRB 231017A: Las Cumbres optical upper limit
  97. GRB 231015A: Glowbug gamma-ray detection
  98. GRB 231017A: LCOGT Optical Upper Limits
  99. GRB231017A: GROWTH-India upper limits on the optical afterglow
  100. GRB 231015A: AstroSat CZTI detection

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