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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"

21103 results found.

  1. GRB 230427A: Osservatorio Astronomico Nastro verde upper limit
  2. GRB 230427A: OSIRIS+/GTC observations
  3. Fermi trigger No 704365743: Global MASTER-Net observations report
  4. GRB 230427A: GIT optical upper limit
  5. GRB 230427A: Bassano Bresciano Observatory upper limit
  6. Swift GRB230427.44: Global MASTER-Net observations report
  7. GRB 230426A: MASTER OT J023135.16-792104.8 optical counterpart discovery
  8. Fermi trigger No 704233744: Global MASTER-Net observations report
  9. GRB 230423A: Swift/UVOT Upper Limits
  10. GRB 230420A: Lowell Discovery Telescope Optical Detection
  11. GRB 221009A: Late-time JWST Observations and Detection of Supernova Emission
  12. GRB 230420A: Swift/UVOT Upper Limits
  13. GRB 230420A: NOT optical afterglow confirmation
  14. GRB 230420A: Gaoyazi/GOT optical upper limit
  15. Fermi-LAT gamma-ray observations of IceCube-230416A
  16. GRB 230414B: Nickel and KAIT telescope optical observations
  17. GRB 230414B: Swift/UVOT Detection
  18. GRB 230414B: Osservatorio Astronomico Nastro Verde - Sorrento: optical observations
  19. GRB 230414B: 3.6m DOT Optical observations, slow decay at early epochs
  20. GRB 230414B: Montarrenti Observatory late time optical afterglow detection
  21. Fermi trigger No 703284533: Global MASTER-Net observations report
  22. GRB 230414B: Lulin 40cm-SLT optical limit
  23. GRB 230414B: Bassano Bresciano Observatory optical observations
  24. GRB 230414B: Redshift from OSIRIS/GTC
  25. GRB 230414B: AbAO optical observations
  26. GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
  27. GRB 230414B: Dabancheng/GHOST optical observations
  28. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230414A
  29. GRB 230414B: SAO RAS optical observations
  30. GRB 230414B: 1.3m DFOT Optical observations
  31. Fermi GRB 230414A: Global MASTER-Net observations report
  32. GRB 230414B: Nanshan/HMT optical afterglow detection
  33. Swift GRB 230414B: Global MASTER-Net observations report
  34. Fermi GRB 230409C: Global MASTER-Net observations report
  35. Fermi GRB 230409A: Global MASTER-Net observations report
  36. Fermi trigger No 702745263: Global MASTER-Net observations report
  37. Swift GRB 230409B: Global MASTER-Net observations report
  38. GRB 230409B: Swift/UVOT Detection
  39. MAXI GRB230408.82: Global MASTER-Net observations report
  40. Fermi-LAT gamma-ray observations of IceCube-230405A
  41. GRB 230405B: MeerLICHT upper limits
  42. IceCube Alert 230405.56: Global MASTER-Net observations report
  43. GRB 230307A: JWST NIRSpec observations, possible higher redshift
  44. GRB 230307A: good match with kilonova models
  45. GRB 230405B: Swift/UVOT Upper Limits
  46. Swift GRB 230405B: Global MASTER-Net observations report
  47. GRB 230307A: JWST observations consistent with the presence of a kilonova
  48. Fermi GRB 230405A: Global MASTER-Net observations report
  49. Fermi-LAT gamma-ray observations of IceCube-230401A and detection of Fermi J0030.2+0005
  50. GRB 230307A: Chandra late-time detection of the X-ray afterglow
  51. GRB 230328B: Swift/UVOT Detection
  52. Fermi GRB 230402A: Global MASTER-Net observations report
  53. GRB 230328B : GRANDMA/Kilonova-Catcher optical detection
  54. GRB 230328B: CAHA 2.2m/CAFOS detection
  55. GRB 230328B: 3.6m DOT multiband optical observation
  56. Fermi trigger No 701883729: Global MASTER-Net observations report
  57. GRB 230328B NUTTelA-TAO / BSTI Early Measurements
  58. GRB 230328B: Liverpool Telescope afterglow detection
  59. GRB 230328B: OHP/T120 optical observations
  60. GRB 230328B: GIT optical follow-up
  61. GRB 230328B: OASDG optical observations
  62. GRB 230328B: Nanshan/NEXT optical upper limit
  63. GRB 230328B: Mondy, AbAO and Kitab optical observations
  64. Fermi GRB 230328A: Global MASTER-Net observations report
  65. GRB 230325A: Swift/UVOT Upper Limits
  66. Fermi trigger No 701313046: Global MASTER-Net observations report
  67. Fermi trigger No 701321709: Global MASTER-Net observations report
  68. GRB 230322B: Swift/UVOT Detection
  69. Swift GRB 230322B: Global MASTER-Net observations report
  70. Fermi trigger No 701071944: Global MASTER-Net observations report
  71. Fermi GRB 230320A: Global MASTER-Net observations report
  72. Fermi GRB 230321A: Global MASTER-Net observations report
  73. Fermi trigger No 701058254: Global MASTER-Net observations report
  74. Fermi trigger No 700976129: Global MASTER-Net observations report
  75. GRB 230307A: Continued Gemini-South observations confirm rapid optical fading
  76. Fermi GRB 230316A: Global MASTER-Net observations report
  77. Fermi GRB 230314A: Global MASTER-Net observations report
  78. GRB 230307A: ATCA radio detection
  79. GRB 230307A: INTEGRAL upper limit on Hard X-ray afterglow
  80. GRB 230307A: Swift/UVOT detection
  81. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230313A
  82. Fermi GRB 230313A: Global MASTER-Net observations report
  83. GRB 230307A: soft X-ray detection with LEIA
  84. GRB 230307A: Swift-XRT afterglow detection
  85. Swift GRB230311.85: Global MASTER-Net observations report
  86. Swift GRB230311.83: Global MASTER-Net observations report
  87. Swift GRB230311.81: Global MASTER-Net observations report
  88. GRB 230307A: SOAR/Goodman detection of the possible host galaxy
  89. Swift GRB230311.84: Global MASTER-Net observations report
  90. Swift GRB230311.82: Global MASTER-Net observations report
  91. Triggers 1159434, 1159435 and 1159437: Swift detection of Sco X-1 due to Star Tracker loss of lock
  92. Alert from the HAWC Burst Monitor HAWC-230311A
  93. TESS Detection of the Optical Afterglow of GRB230307A
  94. Trigger 1159327: Swift detection of SGR1806-20
  95. GRB 230307A: GECKO optical observations and detections of the afterglow
  96. GRB 230307A: Gemini-South Confirmation of the Optical Afterglow
  97. Fermi GRB 230310A: Global MASTER-Net observations report
  98. GRB 230307A: ATLAS information on the ULTRACAM optical afterglow candidate
  99. GRB 230204B: MASTER detection of an object near NTT Optical Afterglow Candidate
  100. GRB 230307A: Possible optical afterglow

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