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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"

21106 results found.

  1. Swift GRB231104.07: Global MASTER-Net observations report
  2. IceCube Alert 231103.39: Global MASTER-Net observations report
  3. Fermi-LAT gamma-ray observations of IceCube-231027A
  4. LIGO/Virgo/KAGRA S231102i: Global MASTER-Net observations report
  5. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  6. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  7. Fermi trigger No 720498201: Global MASTER-Net observations report
  8. Fermi trigger No 720415645: Global MASTER-Net observations report
  9. Fermi GRB 231030B: Global MASTER-Net observations report
  10. Fermi GRB 231030A: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  12. LIGO/Virgo/KAGRA S231029k: Global MASTER-Net observations report
  13. Fermi trigger No 720224759: Global MASTER-Net observations report
  14. Swift GRB 231028A: Global MASTER-Net observations report
  15. IceCube Alert 231027.18: Global MASTER-Net observations report
  16. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  17. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  18. IC231004A: GRANDMA observations of AT2023uqf/ZTF23abidzvf candidate
  19. GRB 231024A: X-shooter spectroscopy of AT2023vuc/GOTO23baj reveals a young supernova with flash ionisation features
  20. GRB 231024A: LCOGT and ZTF detections of the GOTO optical counterpart candidate
  21. GRB 231024A: GOTO optical counterpart candidate
  22. Fermi trigger No 719846439: Global MASTER-Net observations report
  23. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  24. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  25. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  26. Fermi GRB 231020A: Global MASTER-Net observations report
  27. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  28. GRB 231017A: 1.3m DFOT Optical upper limit
  29. IceCube-231004A: Upper limits from Fermi-GBM Observations
  30. Fermi GRB 231019A: Global MASTER-Net observations report
  31. GRB 231017A: Swift/UVOT Upper Limit
  32. GRB 230911C: ATCA detection of possible radio counterpart
  33. GRB 231017A: GOTO optical upper limits
  34. IC231004A: Classification of AT2023uqf/ZTF23abidzvf as a rapidly-evolving supernova with CSM interaction
  35. GRB 231017A: Swift-XRT observations
  36. GRB 231017A: Swift ToO observations
  37. GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
  38. Fermi-LAT gamma-ray observations of IceCube-231014A
  39. (correction) Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field
  40. Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field.
  41. IceCube-231004A: One Candidate Counterpart from the Zwicky Transient Facility
  42. Fermi-LAT gamma-ray observations of IceCube-231004A
  43. transient AT2023sva: radio observations with AMI-LA
  44. AT2023sva / GRB230916B: GIT observations of the afterglow
  45. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230927A
  46. LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
  47. GRB 230812B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  48. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  49. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  50. LIGO/Virgo/KAGRA S230904n: Classification of the candidate AT2023rkw with DBSP
  51. Correction to Fermi GBM Statement for Trigger 716527670/230916144
  52. transient AT2023sva: imaging and spectroscopic observations from MISTRAL at Observatoire de Haute-Provence
  53. GRB 230812B : optical observations from MISTRAL at Observatoire de Haute-Provence
  54. GRB 230918B: GOTO detection of a fast-rising transient in the GBM localisation region
  55. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  56. Detection of self-absorbed radio emission from GRB 230812B with the JVLA + uGMRT
  57. AT 2023sva: NOT observations of the ZTF candidate afterglow
  58. ZTF and SEDM Observations of the Candidate Optical Afterglow AT 2023sva
  59. GRB 230812B: Radio observations with the uGMRT
  60. LIGO/Virgo/KAGRA S230917af: MAXI/GSC observations
  61. Swift GRB230916.18: Global MASTER-Net observations report
  62. Fermi trigger No 716572242: Global MASTER-Net observations report
  63. Fermi trigger No 716544961: Global MASTER-Net observations report
  64. Fermi-LAT gamma-ray observations of IceCube-230914A
  65. Swift GRB230916.19: Global MASTER-Net observations report
  66. Swift GRB230916.18: Global MASTER-Net observations report
  67. Swift GRB230916.13: Global MASTER-Net observations report
  68. Swift GRB230916.12: Global MASTER-Net observations report
  69. Swift GRB230916.11: Global MASTER-Net observations report
  70. GRB 230906A: optical counterpart
  71. GRB 230911A: Swift-XRT afterglow detection
  72. Fermi trigger No 716449174: Global MASTER-Net observations report
  73. IceCube Alert 230914.22: Global MASTER-Net observations report
  74. Fermi trigger No 716419312: Global MASTER-Net observations report
  75. Swift GRB230913.70: Global MASTER-Net observations report
  76. Swift GRB230913.70: Global MASTER-Net observations report
  77. GRB 230911A: Swift ToO observations
  78. Fermi GRB 230913A: Global MASTER-Net observations report
  79. GRB 230911A: GOTO optical counterpart candidate
  80. GRB 230906A: Chandra detection of the X-ray afterglow
  81. Swift GRB 230911C: Global MASTER-Net observations report
  82. GRB 230911C: Swift/UVOT Upper Limits
  83. Fermi trigger No 716145795: Global MASTER-Net observations report
  84. GRB 230911C: GOTO optical upper limits
  85. Fermi GRB 230911B: Global MASTER-Net observations report
  86. GRB 230903A: TESS observations of optical emission
  87. GRB 230906A: Swift/UVOT Upper Limits
  88. GRB 230818A: radio observation with the VLA
  89. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  90. GRB 230906A: Swift-XRT observations
  91. GRB 230906A: Swift ToO observations
  92. Fermi GRB 230906A: Global MASTER-Net observations report
  93. GRB 230903A: VLT/X-shooter optical observations
  94. Fermi trigger No 715552087: Global MASTER-Net observations report
  95. Fermi trigger No 715429986: Global MASTER-Net observations report
  96. Fermi GRB 230903A: Global MASTER-Net observations report
  97. Fermi GRB 230904A: Global MASTER-Net observations report
  98. Swift GRB230903.72: Global MASTER-Net observations report
  99. Integral GRB230902.00: Global MASTER-Net observations report
  100. GRB 230827B: Swift-XRT afterglow detection

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