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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"

16152 results found.

  1. GRB 231111A: TNG tentative redshift
  2. GRB 231111A: Leavitt Observatory optical observations
  3. GRB231111A: Optical follow-up observations with Mephisto
  4. GRB 231111A: GMG observation upper limit
  5. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  6. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  7. GRB 231111A: Mondy optical observations
  8. GRB 231110A: GOTO optical upper limits
  9. GRB 231110A: SAO RAS optical observations
  10. GRB231111A: YAHPT Observations
  11. GRB231111A: GIT confirmation of the optical afterglow
  12. GRB 231111A: MASTER OT earlier detection
  13. GRB 231111A: Nanshan/HMT optical observations
  14. GRB 231111A: Swift detection of a burst with an optical counterpart
  15. IceCube-231103A: No candidates from the Zwicky Transient Facility
  16. GRB 231104A: FRAM-ORM optical limit
  17. GRB 231104A: Wendelstein Optical/Infrared Observations
  18. GRB 231104A: 3.6m DOT optical upper limit
  19. GRB 231104A: NOT upper limit
  20. GRB 231104A: Swift/UVOT Upper Limits
  21. GRB231104A: LCOGT Optical Upper Limits
  22. GRB 231024A: AKO Optical Counterpart Candidate
  23. GRB 231024A: Fermi GBM Observation
  24. GRB 231024A: X-shooter spectroscopy of AT2023vuc/GOTO23baj reveals a young supernova with flash ionisation features
  25. GRB 231024A: LCOGT and ZTF detections of the GOTO optical counterpart candidate
  26. GRB 231024A: GOTO optical counterpart candidate
  27. The photometry of the transient in Messier 31 field: GMG observation
  28. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  29. GRB 231017A: 1.3m DFOT Optical upper limit
  30. IceCube-231004A: Upper limits from Fermi-GBM Observations
  31. GRB 231017A: GOTO optical upper limits
  32. GRB 231017A: JinShan optical upper limit
  33. IC231004A: Classification of AT2023uqf/ZTF23abidzvf as a rapidly-evolving supernova with CSM interaction
  34. GRB 231017A: Las Cumbres optical upper limit
  35. GRB 231017A: LCOGT Optical Upper Limits
  36. GRB231017A: GROWTH-India upper limits on the optical afterglow
  37. (correction) Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field
  38. Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field.
  39. GRB 230827B: 10.4m GTC spectroscopic redshift
  40. Correction to Fermi GBM Statement for Trigger 716527670/230916144
  41. GRB 230812B : optical observations from MISTRAL at Observatoire de Haute-Provence
  42. GRB 230918B: GOTO detection of a fast-rising transient in the GBM localisation region
  43. AT 2023sva: NOT observations of the ZTF candidate afterglow
  44. ZTF and SEDM Observations of the Candidate Optical Afterglow AT 2023sva
  45. GRB 230906A: optical counterpart
  46. GRB 230911A: Swift-XRT afterglow detection
  47. GRB 230911A: GOTO optical counterpart candidate
  48. GRB230911C: BOOTES-6/DPRT optical upper limit
  49. GRB230911C: LCOGT Optical Upper Limits
  50. GRB 230911C: Swift/UVOT Upper Limits
  51. GRB 230911C: GOTO optical upper limits
  52. GRB 230903A: TESS observations of optical emission
  53. GRB 230906A: Swift/UVOT Upper Limits
  54. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  55. GRB 230903A: VLT/X-shooter optical observations
  56. GRB 230903A: LCOGT Optical Upper Limits
  57. GRB 230827B / GRB 230827256: Fermi GBM Observation
  58. Subject: GRB230826A: Swift/UVOT upper limits
  59. GRB 230827.256: AKO Optical follow-up of ZTF23abaanxz (AT 2023qxj)
  60. Swift J1727.8-1613 (GRB 230824A): Osservatorio Astronomico "Nastro Verde" optical observations
  61. GRB 230827.256 : GIT optical follow-up of ZTF23abaanxz/AT2023qxj
  62. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  63. Swift J1727.8-1613 (GRB 230824A): Leavitt Observatory optical observations
  64. GRB 230826A: Mondy optical observations
  65. Swift J1727.8-1613 (GRB 230824A): GAD Observatory La Spezia - optical observations
  66. Swift J1727.8-1613 (GRB 230824A): Bassano Bresciano Observatory optical observations
  67. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  68. GRB 230824A: AKO Optical Afterglow Candidate
  69. GRB 230812B: Assy optical observations, possible SN rise
  70. GRB 230812B: SAO RAS RC-500 and Zeiss-1000 observations
  71. GRB 20230818A: GIT optical upper limit
  72. GRB 230812B : GRANDMA/Kilonova-Catcher optical afterglow detection and upper limits
  73. GRB 230812B: GIT Confirmation of SN rise
  74. GRB 230818A: Nickel and KAIT telescope optical observations
  75. GRB 230818A: SAO RAS 6-m telescope spectroscopy
  76. GRB 230812B: SAO RAS Zeiss-1000 observations
  77. GRB 230818A: further SAO RAS Zeiss-1000 observations
  78. GRB 230818A: AKO Upper Limit
  79. GRB 230818A: Tautenburg observations
  80. GRB 230818A: Bassano Bresciano Observatory optical observations
  81. GRB 230818A: KGO RC-25 optical observations
  82. GRB 230818A: Swift/UVOT Detection
  83. GRB 230818A: NOT photometry and spectroscopy
  84. GRB 230818A: SAO RAS Zeiss-1000 observations
  85. GRB 230818A: GOTO optical afterglow detection
  86. Swift GRB230818.98: Global MASTER-Net OT detection
  87. GRB 230812B: SAO RAS observations, possible re-brightening
  88. GRB 230816A: SVOM/C-GFT optical detection
  89. GRB 230812B: SAO RAS optical observations
  90. GRB 230816A: Osservatorio Astronomico "Nastro Verde" optical observations
  91. GRB 230812B: optical photometry from Konkoly
  92. GRB 230812B: SAO RAS optical observations
  93. GRB230816A: Possible host and GIT detection of optical counterpart
  94. GRB 230816A: Tautenburg observations
  95. GRB 230816A: AKO Optical Observations
  96. GRB 230816A: TShAO and Assy optical observations
  97. GRB 230816A: SAO RAS optical observations
  98. GRB 230816A: Nanshan/HMT optical afterglow detection
  99. GRB 230815A: SOAR/Goodman follow-up imaging
  100. GRB230815A: Swift/UVOT upper limits

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