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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"

31734 results found.

  1. GRB 221017A: Swift-XRT observations
  2. Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)
  3. GRB 221009A: TNG NIR detection
  4. GRB 221009A: BOAO NIR detections
  5. GRB 221009A X-ray light-curve and the indication of TeV light-curve
  6. AGILE detection of a burst from SGR J1935+2154 reported by VZLUSAT-2
  7. GRB 221009A: Spectroscopic detection of emerging SN features
  8. GRB 221009A: Continued LDT Afterglow Monitoring
  9. GRB 221013B: Swift/BAT-GUANO detection
  10. SGR 1935+2154: Bursting activity detected by VZLUSAT-2
  11. AGILE detection of the 2022 October 17 burst from SGR J1935+2154 reported by Konus-Wind
  12. GRB 221009A: GRANDMA observations
  13. SGR 1935+2154: Detection by GRBAlpha
  14. GRB 221009A: Medicina Radio Telescope observations
  15. GRB 221017A: Swift ToO observations
  16. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  17. GRB 221009A: Second epoch of NuSTAR data
  18. IPN triangulation of GRB 221017A (long)
  19. GRB 221016A: Swift-BAT refined analysis
  20. GRB 221016A: Swift/UVOT Detection
  21. GRB 221016A: Swift-XRT refined Analysis
  22. Konus-Wind detection of GRB 221016A
  23. GRB 221016A: Fermi GBM observation
  24. GRB 220926B: Detection by GRBAlpha
  25. GRB 221016A: z-band upper limit, possible afterglow brightening
  26. GRB 221016A: LCOGT Optical Afterglow Detection
  27. GRB 221009A: Faulkes Telescope North continued optical afterglow follow-up
  28. Konus-Wind detection of a short burst coincident with a bright radio burst from SGR 1935+2154
  29. GRB 221009A: continued Assy optical afterglow observations, possible SN evidence
  30. Konus-Wind observation of the recent SGR 1935+2154 activity
  31. GRB 221009A: LEIA X-ray Afterglow Detection
  32. GRB 221009A: ATCA radio spectrum
  33. GRB 221009A: VLT spectroscopic detection of the host galaxy
  34. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  35. GRB 221009A: ATCA detection
  36. GRB 221009A: Armchair Energetics
  37. GRB 221009A: ALMA and ACA detections
  38. GRB 221009A: Fermi LAT data rate effects due to extremely high flux
  39. GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection
  40. GRB 221009A: Pan-STARRS optical photometry
  41. GRB 221009A: VLA detection
  42. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  43. GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
  44. GRB 221009A: OHP optical observations
  45. GRB221009A: RTT-150 optical observations
  46. GRB 221009A: HEBS detection
  47. GRB 221009A: Gemini-South Infrared Afterglow Detection
  48. GRB221009A: Gemini-South Optical Afterglow Detection
  49. GRB 221009A: a 397.7 GeV photon observed by Fermi-LAT at 0.4 day after the GBM trigger
  50. GRB 221009A: Gamma-ray Detection by SIRI-2
  51. GRB221009A: Detection as sudden ionospheric disturbances (SID)
  52. GRB221009A: RTT-150 optical observations
  53. MAXI GRB 221006A: Redshifts of the possible host galaxies
  54. GRB 221009A: search for neutrinos with KM3NeT
  55. GRB 221009A: MeerKAT detection
  56. GRB 221009A: Lowell Discovery Telescope Afterglow Detection
  57. GRB221009A: LCOGT Continued Observations - Optical Upper Limits
  58. Fermi Gamma-ray Burst Monitor continues to detect SGR 1935+2154
  59. GRB 221009A/Swift J1913.1+1946: low-frequency ASKAP observations
  60. GRB 221006A: Swift-XRT afterglow detection
  61. GRB 221009A: MITSuME Okayama optical observation
  62. GRB 221009A: Sayan observatory 1.6-m telescope observations
  63. GRB 221009A: GMG observation
  64. Afterglow limits of GRB 221006A from OHP
  65. GRB221009A: optical afterglow measurements from Konkoly Observatory
  66. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  67. GRB 221009A: COATLI Continued Monitoring of the Afterglow
  68. INTEGRAL detection of a burst from SGR J1935+2154
  69. GRB 221009A: NuSTAR Detection
  70. GRB 221009A: NICER follow-up observations
  71. GRB 221009A: LCOGT Optical Afterglow Detection
  72. GRB 221009A: COATLI Detection of the Afterglow
  73. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  74. GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis
  75. GRB 221009A: Detection by GRBAlpha
  76. GRB 221009A: Sintez-Newton/CrAO optical observations
  77. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  78. GRB 221006A: Swift ToO observations
  79. Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A
  80. GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
  81. GRB 221009A: BlackGEM optical observations
  82. LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV
  83. GRB 221009A: NOEMA mm detection
  84. GRB 221006A: CALET Gamma-Ray Burst Monitor detection
  85. GRB 221009A: Continued Swift/XRT observations
  86. GRB 221009A/Swift J1913.1+1946: Assy optical afterglow observation
  87. GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations
  88. Konus-Wind detection of GRB 221009A
  89. GRB 221009A: Lulin SLT-40cm optical observations
  90. Swift J1913.1+1946: New Photometry
  91. GRB 221009A: Upper limits from a neutrino search with IceCube
  92. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  93. GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
  94. GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
  95. GRB221009A/Swift J1913.1+1946: INTEGRAL SPI/ACS observations
  96. ​GRB 221009A: Multi-color detection of the optical
  97. GRB 221009A: Fermi-LAT refined analysis
  98. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  99. GRB 221009: Swift/UVOT Detection
  100. GRB221009A/Swift J1913.1+1946: ATA follow-up observations

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