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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"

16199 results found.

  1. GRB 230204B: LCOGT Optical Upper Limits
  2. GRB 230204B: Swift/UVOT Upper Limits
  3. GRB 230205A: Swift/UVOT Upper Limits
  4. GRB 230205A: LCOGT Optical Upper Limits
  5. GRB 230204B: Swift-XRT afterglow detection
  6. GRB 230204B: 3.6m DOT optical observation
  7. GRB 230205A: SVOM/C-GFT optical upper limit
  8. GRB 230205A: OHP/T193 optical observations
  9. GRB 230204B: VLT/X-shooter redshift
  10. GRB 230204B: ATLAS detection of the optical afterglow and a projected location in a nearby galaxy group
  11. GRB 230205A: BOOTES-5/JGT early optical upper limit
  12. IceCube-230201A: BOOTES-4/MET Optical Upper Limits
  13. GRB 230204B: GIT discovery of the likely optical afterglow
  14. GRB 230204A: Swift/UVOT Upper Limits
  15. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  16. GRB 230201B: TURBO Optical Upper Limits
  17. ZTF23aabmzlp/AT2023azs: Lulin 1m LOT optical observations
  18. ZTF23aabmzlp/AT2023azs: VLA radio detection
  19. ZTF23aaarlti/AT2023avj: AMI-LA radio detection
  20. ZTF23aabmzlp/AT2023azs: AMI-LA radio upper limit
  21. ZTF23aabmzlp/AT2023azs: LCOGT Optical Detection
  22. ZTF23aaarlti/AT2023avj: Assy continued optical observations
  23. ZTF23aabmzlp/AT2023azs: Mondy and AbAO optical observations
  24. AT2023avj: X-ray Detection with Swift/XRT
  25. ZTF23aabmzlp/AT2023azs: 1.3m DFOT optical observations
  26. ZTF23aaarlti/AT2023avj: VLA radio detection
  27. ZTF23aabmzlp/AT2023azs: Zwicky Transient Facility discovery of a fast optical transient
  28. IceCube-230122A: BOOTES-2/TELMA Optical Upper Limit
  29. AT2023avj ZTF Candidate: Assy optical observations
  30. ZTF and LT Observations of AT2023avj, a Candidate Optical Afterglow
  31. GRB 230123A: LCOGT Optical Upper Limits
  32. GRB 230123A: Swift/UVOT Upper Limits
  33. GRB 230123A: Zadko observatory - Gingin optical observations
  34. GRB 230116D: 3.6m DOT optical upper limit
  35. GRB 230116D: SAO RAS further observations
  36. GRB 230116D: SAO RAS photometry
  37. GRB 230116D: KGO RC-25 optical observations
  38. GRB 230116D: Sintez-Newton/CrAO optical observations
  39. GRB 230116D: LCOGT Optical Upper Limit
  40. GRB 230116D: SAO RAS redshift
  41. GRB 230116D: GIT optical follow-up
  42. GRB 230116D: GIT optical follow-up
  43. GRB 230116D: Sintez-Newton/CrAO optical afterglow detection
  44. GRB 230116D: Nanshan/NEXT optical afterglow detection
  45. IceCube-230112A: BOOTES-4/MET Optical Upper Limit
  46. GRB 221231A: 3.6m DOT optical upper limit
  47. IceCube-221229A: BOOTES-2/TELMA Optical Upper Limit
  48. ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
  49. GRB 221226B: LCOGT Optical Upper Limits
  50. GRB 221226B: Swift-UVOT Detection
  51. GRB 221226B: VLT/X-shooter redshift and host galaxy
  52. IceCube-221224A: BOOTES-4/MET Optical Upper Limit
  53. IceCube-221223A: BOOTES-4/MET Optical Observations
  54. GRB 221218A: 3.6m DOT optical upper limit
  55. GRB 221218A: MITSuME Akeno optical upper limits
  56. GRB 221218A: BOOTES-4/MET and OSN optical upper limits
  57. GRB 221218A: KAIT Optical Upper Limit
  58. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  59. GRB 221216A: Swift/UVOT Upper Limits
  60. GRB 221216A: Zadko observatory - Gingin optical observations
  61. GRB 221216A: Nanshan/NEXT optical upper limits
  62. GRB 221009A: MuSCAT3 observations
  63. Swift/BAT trigger #1143281 is not a GRB
  64. GRB 221202A: VLT/FORS2 Afterglow Discovery
  65. GRB 221202A: LCOGT Optical Upper Limits
  66. GCN: GRB 221201A: Swift/UVOT Upper Limits
  67. Optical polarization observation of GRB 221009A
  68. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  69. GRB 221120A: TURBO Optical Upper Limit
  70. GRB 221120A: VIRT Optical Upper Limit
  71. GRB 221120A: Liverpool Telescope Upper Limits
  72. GRB 221120A: Archival PS1 Imaging of Faint Source near XRT position
  73. GRB221120A: Montarrenti Observatory Upper Limit
  74. GRB 221120A: Swift/UVOT Upper Limits
  75. GRB 221120A: LDT Optical Afterglow Candidate
  76. GRB 221120A: GIT upper limits on optical afterglow
  77. GRB 221115B: LCOGT Optical Upper Limits
  78. GRB 221115B : MeerLICHT upper limits
  79. GRB 221110A: VLT/X-shooter redshift
  80. GRB 221110A: LCOGT Optical Afterglow Detection
  81. GRB 221110A: Swift detection of a burst with an optical counterpart
  82. Swift GRB221110.10: Global MASTER-Net OT detection
  83. GRB 221009A: Hubble Space Telescope observations
  84. Correction to GCN 32852 (GRB 221009A: SARA-RM 1m Optical Afterglow Detection)
  85. GRB 221028A: GRANDMA observations
  86. GRB 221027B: GRANDMA observations
  87. GRB 221028A: 1.3m DFOT Optical upper limit
  88. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  89. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  90. GRB 221028A: AKO Optical Upper Limit
  91. GRB 221028A: CrAO/ZTSh optical upper limit
  92. GRB 221028A: HCT optical upper limit
  93. GRB 221028A: MITSuME Okayama optical upper limits
  94. GRB 221028A: LCOGT Optical Upper Limits
  95. GRB 221028A: BOOTES-4/MET optical upper limit
  96. GRB 221028A: GIT optical upper limit
  97. GRB 221027B: Swift/UVOT Upper Limits
  98. GRB 221027B: FRAM-ORM and Ondrejov SBT optical limits
  99. GRB 221027B: BOOTES-1 optical upper limit
  100. GRB 221024A: Mondy optical observations

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