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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

21109 results found.

  1. High-precision position of the compact radio counterpart to GRB221009A
  2. GRB 221028A: GRANDMA observations
  3. GRB 221027B: GRANDMA observations
  4. GRB 221028A: 1.3m DFOT Optical upper limit
  5. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  6. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  7. GRB 221028A: HCT optical upper limit
  8. Swift GRB 221028A: Global MASTER-Net observations report
  9. GRB 221027B: Swift/UVOT Upper Limits
  10. Swift GRB 221027B: Global MASTER-Net observations report
  11. GRB 221024A: Mondy optical observations
  12. GRB 221009A: Further Gemini-South Infrared Observations
  13. GRB 221024A: GRANDMA observations
  14. GRB 221009A: SARA-RM 1m Optical Afterglow Detection
  15. GRB 221009A: spectroscopic confirmation of SN in LBT spectra
  16. GRB 221024A: Swift/UVOT UV upper limits
  17. GRB 221022A: Swift-XRT observations
  18. LAT GRB221025.04: Global MASTER-Net observations report
  19. GRB 221022A: Swift ToO observations
  20. GRB 221009A: James Webb Space Telescope Observations
  21. GRB 221009A: optical observations, SN photometric evidence
  22. GRB 221009A: 1.3m DFOT Optical Observations
  23. GRB221009A: LBT optical imaging
  24. GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow
  25. GRB 221017A: Swift-XRT observations
  26. GRB 221009A: BOAO NIR detections
  27. GRB 221009A X-ray light-curve and the indication of TeV light-curve
  28. GRB 221009A: Spectroscopic detection of emerging SN features
  29. GRB 221009A: Continued LDT Afterglow Monitoring
  30. GRB 221009A: GRANDMA observations
  31. GRB 221009A: Medicina Radio Telescope observations
  32. GRB 221017A: Swift ToO observations
  33. GRB 221009A: Second epoch of NuSTAR data
  34. GRB 221016A: Swift/UVOT Detection
  35. MAXI GRB221017.24: Global MASTER-Net observations report
  36. Swift GRB221016.99: Global MASTER-Net observations report
  37. GRB 221009A: Faulkes Telescope North continued optical afterglow follow-up
  38. GRB 221009A: continued Assy optical afterglow observations, possible SN evidence
  39. GRB 221009A: ATCA radio spectrum
  40. GRB 221009A: ATCA detection
  41. GRB 221009A: ALMA and ACA detections
  42. GRB 221009A: Fermi LAT data rate effects due to extremely high flux
  43. GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection
  44. GRB 221009A: Pan-STARRS optical photometry
  45. GRB 221009A: VLA detection
  46. GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
  47. GRB 221009A: OHP optical observations
  48. GRB221009A: RTT-150 optical observations
  49. GRB 221009A: Gemini-South Infrared Afterglow Detection
  50. GRB221009A: Gemini-South Optical Afterglow Detection
  51. GRB 221009A: a 397.7 GeV photon observed by Fermi-LAT at 0.4 day after the GBM trigger
  52. GRB221009A: RTT-150 optical observations
  53. MAXI GRB 221006A: Redshifts of the possible host galaxies
  54. GRB 221009A: MeerKAT detection
  55. GRB 221009A: Lowell Discovery Telescope Afterglow Detection
  56. GRB221009A: LCOGT Continued Observations - Optical Upper Limits
  57. GRB 221009A/Swift J1913.1+1946: low-frequency ASKAP observations
  58. Fermi trigger No 687345829: Global MASTER-Net observations report
  59. Fermi trigger No 687344475: Global MASTER-Net observations report
  60. Fermi trigger No 687340841: Global MASTER-Net observations report
  61. Fermi trigger No 687337536: Global MASTER-Net observations report
  62. GRB 221006A: Swift-XRT afterglow detection
  63. GRB 221009A: Sayan observatory 1.6-m telescope observations
  64. Fermi trigger No 687281393: Global MASTER-Net observations report
  65. Integral GRB221013.04: Global MASTER-Net observations report
  66. Integral GRB221013.00: Global MASTER-Net observations report
  67. Integral GRB221012.99: Global MASTER-Net observations report
  68. Integral GRB221012.94: Global MASTER-Net observations report
  69. Integral GRB221012.91: Global MASTER-Net observations report
  70. Integral GRB221012.88: Global MASTER-Net observations report
  71. Integral GRB221012.87: Global MASTER-Net observations report
  72. Integral GRB221012.77: Global MASTER-Net observations report
  73. Integral GRB221012.74: Global MASTER-Net observations report
  74. Integral GRB221012.72: Global MASTER-Net observations report
  75. Integral GRB221012.71: Global MASTER-Net observations report
  76. Integral GRB221012.68: Global MASTER-Net observations report
  77. Integral GRB221012.68: Global MASTER-Net observations report
  78. Integral GRB221012.98: Global MASTER-Net observations report
  79. Afterglow limits of GRB 221006A from OHP
  80. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  81. GRB 221009A/Swift J1913.1+1946: SMA observations
  82. INTEGRAL shows increasing activity in SGR J1935+2154
  83. GRB 221009A: COATLI Continued Monitoring of the Afterglow
  84. Integral GRB221012.63: Global MASTER-Net observations report
  85. Integral GRB221012.61: Global MASTER-Net observations report
  86. Integral GRB221012.60: Global MASTER-Net observations report
  87. Integral GRB221012.53: Global MASTER-Net observations report
  88. GRB 221009A/Swift J1913.1+1946: eMERLIN observations
  89. Fermi trigger No 687205006: Global MASTER-Net observations report
  90. INTEGRAL detection of a burst from SGR J1935+2154
  91. GRB 221009A: NuSTAR Detection
  92. GRB 221009A: NICER follow-up observations
  93. GRB 221009A: LCOGT Optical Afterglow Detection
  94. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  95. GRB 221009A: planned observation with the Imaging X-ray Polarimetry Explorer (IXPE)
  96. Fermi trigger No 687190301: Global MASTER-Net observations report
  97. GRB 221009A: Sintez-Newton/CrAO optical observations
  98. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  99. GRB 221006A: Swift ToO observations
  100. GRB 221009A: BlackGEM optical observations

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