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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. LIGO/Virgo S191109d: Global MASTER-Net observations report
  2. LIGO/Virgo S191109d: upper limits from AGILE-GRID observations mailed-by:
  3. LIGO/Virgo S191109d: upper limits from AGILE/MCAL observations
  4. LIGO/Virgo S191109d: Upper limits from Fermi-GBM Observations
  5. LIGO/Virgo S191109d: Coverage and upper limits from MAXI/GSC observations
  6. GRB 191106A: Swift/UVOT Upper Limits
  7. ZTF19abvizsw: Upper limits from Konus-Wind observations
  8. LIGO/Virgo S191105e: No counterpart candidates in Fermi-LAT observations
  9. LIGO/Virgo S191105e: Coverage and upper limits from MAXI/GSC observations
  10. LIGO/Virgo S191105e: no counterpart candidates in the Swift/BAT observations
  11. GRB 191106A: NOT optical upper limit
  12. LIGO/Virgo S191105e: No counterpart candidates in HAWC observations
  13. LIGO/Virgo S191105e: upper limits from AGILE/GRID observations
  14. LIGO/Virgo S191105e: Upper limits from Fermi-GBM Observations
  15. LIGO/Virgo S191105e: Global MASTER-Net observations report
  16. LIGO/Virgo S191105e: upper limits from AGILE/MCAL observations
  17. GRB 191106A: BOOTES-4/MET optical limit
  18. GRB 191106A: MASTER optical observation
  19. GRB191016A GROND observations
  20. GRB 191031D: Chandra upper limit
  21. Fermi trigger No 594592184: Global MASTER-Net observations report
  22. Fermi trigger No 594523229: Global MASTER-Net observations report
  23. Swift GRB191105.01: Global MASTER-Net observations report
  24. GRB 191101A: Swift/UVOT Upper Limits
  25. Fermi trigger No 594563923: Global MASTER-Net observations report
  26. Fermi trigger No 594557071: Global MASTER-Net observations report
  27. Fermi trigger No 594551878: Global MASTER-Net observations report
  28. Fermi trigger No 594528816: Global MASTER-Net observations report
  29. GRB 191031D: Zwicky Transient Facility Follow-Up of a Swift Short GRB (Trigger 594249816/191031891)
  30. GRB 191031D: Gemini optical upper limit
  31. Baksan Neutrino Observatory Alert 191102.06: Global MASTER-Net observations report
  32. GRB 191101A: VIRT Optical Upper Limits
  33. Fermi trigger No 594336535: Global MASTER-Net observations report
  34. Swift GRB191101.88: Global MASTER-Net observations report
  35. Fermi trigger No 594227699: Global MASTER-Net observations report
  36. GRB 191031D: MMT Binospec Optical Upper Limit
  37. GRB 191031D: Swift/UVOT Upper Limits
  38. GRB 191031C: Swift/UVOT Detection
  39. Konus-Wind observation of GRB 191031D
  40. GRB 191031D: AGILE/MCAL observations
  41. GRB 191031D: COATLI Optical Observations
  42. GRB 191031D: RATIR Optical and NIR Observations
  43. GRB 191031D: VLA 9.8 GHz upper limit
  44. Swift GRB191031.89: Global MASTER-Net observations report
  45. Fermi trigger No 594175000: Global MASTER-Net observations report
  46. GRB 191031A: COATLI Optical Observations
  47. GRB 191019A: Zadko Telescope optical observations
  48. GRB 191029A: Swift/UVOT Upper Limits
  49. GRB 191028B: MASTER optical observation
  50. GRB 191029A: Swift-XRT observations
  51. GRB 191023A: MASTER optical observation
  52. GRB 191024A: Swift/UVOT Upper Limits
  53. GRB 191024A: Afterglow Upper Limits with LCO
  54. GRB 191024A: VLT/X-shooter optical observations
  55. GRB 191024A: GROND early upper limits
  56. GRB191024A: MASTER optical observation
  57. GRB 191019A: NOT optical afterglow and host association confirmation
  58. GRB 191019A: Nanshan-0.6m optical observations
  59. GRB 191019A: Swift/UVOT Detection
  60. Swift GRB191019.67: Global MASTER-Net observations report
  61. GRB 191019A: GROND observations
  62. GRB 191019A: NOT optical spectroscopy of candidate counterpart
  63. GRB 191019A: NOT optical observations
  64. Fermi trigger No 593176520: Global MASTER-Net observations report
  65. Alert from the HAWC Burst Monitor HAWC-191019A
  66. GRB 191019A: TSHAO optical observations, probable afterglow and host galaxy
  67. GRB 191019A: Swift-XRT observations
  68. Swift GRB191019.63: Global MASTER-Net observations report
  69. GRB 191019A: MASTER optical observation
  70. GRB 191017B: Swift/UVOT Upper Limits
  71. GRB 191016A: REM optical observations
  72. GRB 191016A: Swift-XRT afterglow detection
  73. Fermi trigger No 593045905: Global MASTER-Net observations report
  74. GRB 191016A: Swift/UVOT Detection
  75. GRB 191016A: early time BOOTES Network and follow-up 1.5m OSN optical observations
  76. GRB 191016A: RATIR Optical and NIR Observations
  77. Baksan Neutrino Observatory Alert 191016.51: Global MASTER-Net observations report
  78. GRB 191016A: COATLI Optical Observations and Detection of the Afterglow
  79. Swift GRB191016.17: Global MASTER-Net observations report
  80. Fermi trigger No 592818648: Global MASTER-Net observations report
  81. ANTARES 191011A: MASTER optical observation befor and after trigger
  82. GRB 191011A: Swift/UVOT Detection
  83. GRB 191011A: RATIR Optical and NIR Observations
  84. GRB 19011A: Optical Afterglow Detection with LCO
  85. GRB 191011A: correction of reported magnitudes
  86. GRB 191011A: GROND Detection of the Optical/NIR afterglow
  87. GRB 191011A: VLT X-shooter redshift from RRM Observations
  88. Swift GRB191011.19: Global MASTER-Net observations report
  89. LIGO/Virgo S190930t: Continued Swift observations of AT2019sbk
  90. Fermi trigger No 592211224: Global MASTER-Net observations report
  91. Fermi trigger No 592211224: Global MASTER-Net observations report
  92. GRB 191004B: Swift/UVOT Detection
  93. GRB 191004B: Continued Optical Afterglow Monitoring with LCO
  94. GRB 191004A: Swift/UVOT Detection
  95. GRB 191004A: Optical Detection with LCO
  96. LIGO/Virgo S190930s: no counterpart candidate in the SVOM/GWAC observations
  97. LIGO/Virgo S190930t: Magellan/IMACS imaging of Swift J224718-581442 (AT2019sbk)
  98. LIGO/Virgo S190930t: Swift XRT observations, no secure afterglow found
  99. GRB 190928A: AstroSat CZTI detection
  100. LIGO/Virgo S190930t: Swift discovery of Swift J224718-581442 (AT2019sbk): a fading UV transient with an X-ray counterpart

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