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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"

28084 results found.

  1. LIGO/Virgo/KAGRA S231129ac: Updated Sky localization
  2. GRB 231129A: Swift-XRT refined Analysis
  3. Fermi trigger No 722977823: Global MASTER-Net observations report
  4. GRB 231129B: MAXI/GSC detection
  5. Fermi-LAT gamma-ray observations of IceCube-231125A
  6. LIGO/Virgo/KAGRA S231129ac: Identification of a GW compact binary merger candidate
  7. GRB 231129A: INTEGRAL detection of a long GRB
  8. GRB 231129A: Swift detection of a burst
  9. LIGO/Virgo/KAGRA S231127cg: Updated Sky localization
  10. GRB 231123C: Fermi GBM Observation
  11. GRB 231123B: Fermi GBM Observation
  12. IceCube-231125A: Upper limits from a search for additional neutrino events in IceCube
  13. LIGO/Virgo/KAGRA S231127cg: Identification of a GW compact binary merger candidate
  14. GRB 231117A: MeerKAT 1.3GHz detection
  15. GRB 231127A: AstroSat CZTI detection
  16. GRB 231125A (short): Glowbug gamma-ray detection
  17. GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  18. GRB 231125A: AstroSat CZTI detection of a short burst
  19. GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
  20. GRB 231123C: Insight-HXMT/HE detection
  21. Fermi trigger No 722460326: Global MASTER-Net observations report
  22. GRB 231123C (short): Glowbug gamma-ray detection
  23. GRB 231124A: Glowbug gamma-ray detection
  24. GRB230728A: VIRT optical upper limit
  25. GRB230506C: VIRT optical upper limit
  26. GRB230506B: VIRT optical upper limit
  27. GRB 231123C: Swift/BAT-GUANO detection of a short burst likely outside the coded FOV
  28. LIGO/Virgo/KAGRA S231118an: Updated Sky localization and EM Bright Classification
  29. GRB 231117A: Mondy optical observations
  30. LIGO/Virgo/KAGRA S231123cg: Identification of a GW compact binary merger candidate
  31. GRB 231118A: REM optical afterglow detection
  32. GRB 231122B: AstroSat CZTI detection
  33. GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  34. GRB 231122B: Glowbug gamma-ray detection
  35. GRB 231117A: Continued GTC Observations
  36. GRB 231122A: GECAM detection
  37. GRB 231122B: GECAM detection
  38. GRB 231117A: Swift/UVOT late time observations
  39. GRB 231117A: GTC Near-Infrared Observations
  40. GRB 231117A: Swift-BAT refined analysis
  41. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  42. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
  43. LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
  44. LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
  45. LIGO/Virgo/KAGRA S231119u: Updated Sky localization and Source Classification
  46. LIGO/Virgo/KAGRA S231118ab: Updated Sky localization and Source Classification
  47. LIGO/Virgo/KAGRA S231118d: Updated Sky localization and Source Classification
  48. GRB 231118A: VZLUSAT-2 detection
  49. GRB 231117A: AMI-LA radio observations
  50. GRB 231118A: Swift-BAT refined analysis
  51. 231118A: Swift-UVOT Detection
  52. GRB231117A: Swift-UVOT detection
  53. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  54. GRB 231118B: Fermi GBM observation
  55. GRB 231118A: Fermi GBM observation
  56. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  57. GRB 231117A: Swift-XRT refined Analysis
  58. GRB 231118A: Swift-XRT refined Analysis
  59. GRB 231118A: MeerLICHT afterglow detection
  60. LIGO/Virgo/KAGRA S231119u: One counterpart neutrino candidate from IceCube neutrino searches
  61. GRB 231117A: OHP/T120 optical observations
  62. GRB 231118A: VLT/X-shooter redshift
  63. Fermi trigger No 722039659: Global MASTER-Net observations report
  64. GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
  65. LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
  66. GRB 231117A: AKO Follow-Up Observation
  67. GRB 231118A: Las Cumbres optical detection
  68. GRB 231118B: BALROG localization (Fermi Trigger 722039659 / GRB 231118940)
  69. GRB 231118A: LCOGT Optical Observations
  70. GRB 231118A: Enhanced Swift-XRT position
  71. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  72. GRB 231118A: Skynet Optical Afterglow Discovery
  73. LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
  74. GRB 231117A: GRBAlpha detection
  75. LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
  76. GRB 231115A: Wendelstein Optical/Infrared Observations
  77. GRB 231115A: JinShan optical upper limits
  78. LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
  79. GRB 231117A: GIT optical follow-up
  80. GRB 231117A: LT observations consistent with fading
  81. GRB 231117A: REM optical and NIR early-time observations
  82. GRB 231117A: AKO Optical Upper Limit
  83. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  84. GRB 231117A (short): Glowbug gamma-ray detection
  85. GRB 231117A: ATLAS non-detection of an optical counterpart
  86. GRB 231115A : OHP/T120 optical upper limit
  87. GRB 231117A : MITSuME Akeno optical upper limits
  88. GRB 231117A: Enhanced Swift-XRT position
  89. GRB 231117A: AstroSat CZTI detection of a bright short burst
  90. GRB 231117A: Swift detection of a bright short burst
  91. GRB 231115A: Non-detection of radio emission with CHIME/FRB
  92. GRB 231111A: Swift/UVOT Detection
  93. MAGIC observation of GRB 231115A, a possible magnetar giant flare
  94. GRB231115A: Liverpool Telescope imaging
  95. GRB 231115A: NuSTAR Follow-Up Observations
  96. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  97. GRB 231115A: Swift-XRT and Swift-UVOT observations
  98. GRB 231115A: AGILE/MCAL upper limits
  99. GRB 231115A: Insight-HXMT/HE detection
  100. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar

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