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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

26038 results found.

  1. Swift GRB 221027B: Global MASTER-Net observations report
  2. GRB 221027B: Swift-XRT refined Analysis
  3. GRB 221027B: BOOTES-1 optical upper limit
  4. GRB 221027B: Enhanced Swift-XRT position
  5. GRB 221027B: Swift detection of a burst
  6. Konus-Wind detection of GRB 221022B
  7. GRB 221024A: Mondy optical observations
  8. GRB 221027A: Fermi-LAT detection
  9. GRB 221009A: Further Gemini-South Infrared Observations
  10. GRB 221024A: GRANDMA observations
  11. IPN triangulation of GRB 221022C (short)
  12. GRB 221024A: Swift-BAT refined analysis
  13. GRB 221009A: SARA-RM 1m Optical Afterglow Detection
  14. GRB 221009A: spectroscopic confirmation of SN in LBT spectra
  15. GRB 221024A: Swift/UVOT UV upper limits
  16. GRB 221022A: Swift-XRT observations
  17. GRB 221024A: Swift-XRT refined Analysis
  18. GRB 221022B: Detection by GRBAlpha
  19. GRB 221025A: Fermi-LAT detection
  20. IPN triangulation of GRB 221022B (long)
  21. GRB 221024A: GIT confirmation of the optical afterglow
  22. GRB 221024A: Enhanced Swift-XRT position
  23. GRB 221024A: D50 candidate afterglow
  24. GRB 221022B: AstroSat CZTI detection
  25. GRB 221022A: Fermi GBM detection
  26. GRB 221022A: Swift ToO observations
  27. GRB 221023A: Fermi-LAT detection
  28. GRB 221022B: Fermi GBM detection
  29. GRB 221021A: Fermi GBM observation
  30. GRB 221009A: Determination of the black holes mass and spin
  31. GRB 221024A: Swift detection of a burst
  32. GRB 221022A: Swift/BAT-GUANO detection
  33. GRB 221022B: Swift/BAT-GUANO detection outside the coded FOV
  34. GRB 221009A: James Webb Space Telescope Observations
  35. GRB 221009A: optical observations, SN photometric evidence
  36. GRB 221021A: Swift/BAT-GUANO detection outside the coded FOV
  37. GRB 221009A: 1.3m DFOT Optical Observations
  38. GRB221009A: LBT optical imaging
  39. GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow
  40. GRB 221017A: Swift-XRT observations
  41. Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)
  42. GRB 221009A: TNG NIR detection
  43. GRB 221009A: BOAO NIR detections
  44. GRB 221009A X-ray light-curve and the indication of TeV light-curve
  45. GRB 221009A: Spectroscopic detection of emerging SN features
  46. GRB 221009A: Continued LDT Afterglow Monitoring
  47. GRB 221013B: Swift/BAT-GUANO detection
  48. AGILE detection of the 2022 October 17 burst from SGR J1935+2154 reported by Konus-Wind
  49. GRB 221009A: GRANDMA observations
  50. The probability of observing GRB 221009A at z = 0.151
  51. GRB 221017A: Swift ToO observations
  52. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  53. GRB 221009A: Second epoch of NuSTAR data
  54. GRB 221016A: Swift-BAT refined analysis
  55. GRB 221016A: Swift/UVOT Detection
  56. GRB 221016A: Swift-XRT refined Analysis
  57. Konus-Wind detection of GRB 221016A
  58. GRB 221016A: Fermi GBM observation
  59. GRB 221009A: A type I BdHN of exceptional energetics
  60. GRB 221016A: z-band upper limit, possible afterglow brightening
  61. GRB 221016A: Enhanced Swift-XRT position
  62. GRB 221016A: LCOGT Optical Afterglow Detection
  63. GRB 221016A: Swift detection of a burst
  64. Swift GRB221016.99: Global MASTER-Net observations report
  65. GRB 221009A: Faulkes Telescope North continued optical afterglow follow-up
  66. GRB 221009A: continued Assy optical afterglow observations, possible SN evidence
  67. GRB 221009A: LEIA X-ray Afterglow Detection
  68. GRB 221009A: ATCA radio spectrum
  69. GRB 221009A: VLT spectroscopic detection of the host galaxy
  70. GRB 221009A: Armchair Energetics
  71. GRB 221009A: ALMA and ACA detections
  72. GRB 221009A: Fermi LAT data rate effects due to extremely high flux
  73. GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection
  74. GRB 221009A: Pan-STARRS optical photometry
  75. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  76. GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
  77. GRB 221009A: IXPE preliminary upper limits of X-ray polarization
  78. GRB 221009A: HEBS detection
  79. GRB 221009A: Gemini-South Infrared Afterglow Detection
  80. GRB221009A: Gemini-South Optical Afterglow Detection
  81. GRB 221009A: Gamma-ray Detection by SIRI-2
  82. GRB221009A: Detection as sudden ionospheric disturbances (SID)
  83. MAXI GRB 221006A: Redshifts of the possible host galaxies
  84. GRB 221009A: search for neutrinos with KM3NeT
  85. GRB 221009A: Lowell Discovery Telescope Afterglow Detection
  86. GRB221009A: LCOGT Continued Observations - Optical Upper Limits
  87. GRB 221009A/Swift J1913.1+1946: low-frequency ASKAP observations
  88. GRB 221006A: Swift-XRT afterglow detection
  89. GRB 221009A: MITSuME Okayama optical observation
  90. GRB 221009A: Sayan observatory 1.6-m telescope observations
  91. GRB 221009A: GMG observation
  92. Afterglow limits of GRB 221006A from OHP
  93. GRB221009A: optical afterglow measurements from Konkoly Observatory
  94. GRB 221009A/Swift J1913.1+1946: SMA observations
  95. GRB 221009A: COATLI Continued Monitoring of the Afterglow
  96. GRB 221009A/Swift J1913.1+1946: eMERLIN observations
  97. INTEGRAL detection of a burst from SGR J1935+2154
  98. GRB 221009A: NuSTAR Detection
  99. GRB 221009A: LCOGT Optical Afterglow Detection
  100. GRB 221009A: COATLI Detection of the Afterglow

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