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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"

16151 results found.

  1. GRB 230217A: VLT/FORS2 optical observations and candidate counterpart
  2. GRB 230216A Mondy Observations
  3. GRB 230217A: Swift/UVOT Upper Limits
  4. GRB 230216A: Swift/UVOT Upper Limits
  5. GRB 230217A: Gemini South optical upper limits
  6. GRB 230217A: Gemini-South Optical Observation
  7. IceCube-230217A: BOOTES-4/MET Optical Observations
  8. GRB 230216A: SVOM/C-GFT optical upper limit
  9. GRB 230204B: Lowell Discovery Telescope Observations
  10. GRB 230216A: Zadko observatory - Gingin optical observations
  11. GRB 230204B: ATCA radio detection
  12. GRB 230205A: 6 GHz VLA observations
  13. GRB 230204B: MASTER early OT detection
  14. ZTF23aabmzlp/AT2023azs: Neil Gehrels Swift Observatory X-ray observations
  15. GRB 230204B: LCOGT Optical Upper Limits
  16. GRB 230204B: Swift/UVOT Upper Limits
  17. GRB 230205A: Swift/UVOT Upper Limits
  18. GRB 230205A: LCOGT Optical Upper Limits
  19. GRB 230204B: Swift-XRT afterglow detection
  20. GRB 230204B: 3.6m DOT optical observation
  21. GRB 230205A: SVOM/C-GFT optical upper limit
  22. GRB 230205A: OHP/T193 optical observations
  23. GRB 230204B: VLT/X-shooter redshift
  24. GRB 230204B: ATLAS detection of the optical afterglow and a projected location in a nearby galaxy group
  25. GRB 230205A: BOOTES-5/JGT early optical upper limit
  26. IceCube-230201A: BOOTES-4/MET Optical Upper Limits
  27. GRB 230204B: GIT discovery of the likely optical afterglow
  28. GRB 230204A: Swift/UVOT Upper Limits
  29. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  30. GRB 230201B: TURBO Optical Upper Limits
  31. ZTF23aabmzlp/AT2023azs: Lulin 1m LOT optical observations
  32. ZTF23aabmzlp/AT2023azs: VLA radio detection
  33. ZTF23aaarlti/AT2023avj: AMI-LA radio detection
  34. ZTF23aabmzlp/AT2023azs: AMI-LA radio upper limit
  35. ZTF23aabmzlp/AT2023azs: LCOGT Optical Detection
  36. ZTF23aaarlti/AT2023avj: Assy continued optical observations
  37. ZTF23aabmzlp/AT2023azs: Mondy and AbAO optical observations
  38. AT2023avj: X-ray Detection with Swift/XRT
  39. ZTF23aabmzlp/AT2023azs: 1.3m DFOT optical observations
  40. ZTF23aaarlti/AT2023avj: VLA radio detection
  41. ZTF23aabmzlp/AT2023azs: Zwicky Transient Facility discovery of a fast optical transient
  42. IceCube-230122A: BOOTES-2/TELMA Optical Upper Limit
  43. AT2023avj ZTF Candidate: Assy optical observations
  44. ZTF and LT Observations of AT2023avj, a Candidate Optical Afterglow
  45. GRB 230123A: LCOGT Optical Upper Limits
  46. GRB 230123A: Swift/UVOT Upper Limits
  47. GRB 230123A: Zadko observatory - Gingin optical observations
  48. GRB 230116D: 3.6m DOT optical upper limit
  49. GRB 230116D: SAO RAS further observations
  50. GRB 230116D: SAO RAS photometry
  51. GRB 230116D: KGO RC-25 optical observations
  52. GRB 230116D: Sintez-Newton/CrAO optical observations
  53. GRB 230116D: LCOGT Optical Upper Limit
  54. GRB 230116D: SAO RAS redshift
  55. GRB 230116D: GIT optical follow-up
  56. GRB 230116D: GIT optical follow-up
  57. GRB 230116D: SAO RAS observations of OT brightening
  58. GRB 230116D: Sintez-Newton/CrAO optical afterglow detection
  59. GRB 230116D: Nanshan/NEXT optical afterglow detection
  60. IceCube-230112A: BOOTES-4/MET Optical Upper Limit
  61. GRB 221231A: 3.6m DOT optical upper limit
  62. IceCube-221229A: BOOTES-2/TELMA Optical Upper Limit
  63. ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
  64. GRB 221226B: LCOGT Optical Upper Limits
  65. GRB 221226B: Swift-UVOT Detection
  66. GRB 221226B: VLT/X-shooter redshift and host galaxy
  67. IceCube-221224A: BOOTES-4/MET Optical Upper Limit
  68. IceCube-221223A: BOOTES-4/MET Optical Observations
  69. GRB 221218A: 3.6m DOT optical upper limit
  70. GRB 221218A: MITSuME Akeno optical upper limits
  71. GRB 221218A: BOOTES-4/MET and OSN optical upper limits
  72. GRB 221218A: KAIT Optical Upper Limit
  73. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  74. GRB 221216A: Swift/UVOT Upper Limits
  75. GRB 221216A: Zadko observatory - Gingin optical observations
  76. GRB 221216A: Nanshan/NEXT optical upper limits
  77. GRB 221009A: MuSCAT3 observations
  78. Swift/BAT trigger #1143281 is not a GRB
  79. GRB 221202A: VLT/FORS2 Afterglow Discovery
  80. GRB 221202A: LCOGT Optical Upper Limits
  81. GCN: GRB 221201A: Swift/UVOT Upper Limits
  82. Optical polarization observation of GRB 221009A
  83. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  84. GRB 221120A: TURBO Optical Upper Limit
  85. GRB 221120A: VIRT Optical Upper Limit
  86. GRB 221120A: Liverpool Telescope Upper Limits
  87. GRB 221120A: Archival PS1 Imaging of Faint Source near XRT position
  88. GRB221120A: Montarrenti Observatory Upper Limit
  89. GRB 221120A: Swift/UVOT Upper Limits
  90. GRB 221120A: LDT Optical Afterglow Candidate
  91. GRB 221120A: GIT upper limits on optical afterglow
  92. GRB 221115B: LCOGT Optical Upper Limits
  93. GRB 221115B : MeerLICHT upper limits
  94. GRB 221110A: VLT/X-shooter redshift
  95. GRB 221110A: LCOGT Optical Afterglow Detection
  96. GRB 221110A: Swift detection of a burst with an optical counterpart
  97. Swift GRB221110.10: Global MASTER-Net OT detection
  98. GRB 221009A: Hubble Space Telescope observations
  99. Correction to GCN 32852 (GRB 221009A: SARA-RM 1m Optical Afterglow Detection)
  100. GRB 221028A: GRANDMA observations

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