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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"

16150 results found.

  1. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  2. GRB 231216A: AST3-3 YaoAn Optical Upper Limit
  3. GRB 231216A: Swift/UVOT Upper Limits
  4. GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
  5. GRB 231216A: GIT optical upper limit
  6. GRB 231216A: NOT optical upper limits
  7. GRB 231216A: BOOTES-2/TELMA optical upper limit
  8. GRB 231215A: optical afterglow detection from the INAF Asiago Observatory
  9. GRB 231215A: NOT optical observations
  10. GRB 231214A: Swift/UVOT Upper Limits
  11. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  12. GRB 231215A : OHP/T193 optical afterglow detection
  13. GRB 231215A: Swift/UVOT Detection
  14. GRB 231215A: BOOTES-4/MET optical detection
  15. GRB 231215A: AKO Optical Upper Limit
  16. GRB 231214A: REM optical/NIR upper limits
  17. GRB 231215A: GROWTH-India optical follow-up
  18. GRB 231215A : Nanshan/HMT optical observations
  19. GRB 231215A : MITSuME Akeno optical afterglow candidate detection
  20. GRB 231215A: Mondy optical bright afterglow detection
  21. GRB231214A: BOOTES-6/DPRT optical upper limit
  22. GRB 231210B: REM optical/NIR upper limits
  23. GRB 231210B: MeerLICHT afterglow observations
  24. GRB 231210B: VLT/X-shooter redshift
  25. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  26. GRB 231210B: Swift detection of a burst with optical counterpart
  27. Swift GRB231210.90: Global MASTER-Net OT detection
  28. GRB231205B: Swift/UVOT Upper Limits
  29. GRB 231205B: 1.3m DFOT Optical upper limit
  30. GRB 231205B: optical upper limit in TSHAOand AbAO
  31. GRB231115A: TURBO Pre-Burst Optical Upper Limits
  32. GRB 231205B: Ondrejov D50 optical upper limit
  33. GRB 231205B: REM optical/NIR upper limits
  34. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  35. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  36. GRB 231205B : MITSuME Akeno optical upper limits
  37. GRB 231205B: Zadko observatory - Gingin optical observations
  38. GRB 231205B: Gaoyazi/GOT optical upper limit
  39. GRB 231205B: Nanshan/HMT optical upper limit
  40. GRB 231205B: LCOGT Optical Upper Limits
  41. GRB 231205B: AKO Optical Upper Limit
  42. GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
  43. Optical transient in the field of Messier 31, likely a new blazar: back to bright state
  44. GRB 231129A : MITSuME Akeno optical upper limits
  45. GRB 231129A: BOOTES-5/JGT optical upper limit
  46. GRB 231129A: JinShan optical upper limit
  47. GRB 231129A: Swift/UVOT Upper Limits
  48. GRB 231129A: optical upper limit in Mondy observatory
  49. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  50. GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
  51. GRB230728A: VIRT optical upper limit
  52. GRB230506C: VIRT optical upper limit
  53. GRB230506B: VIRT optical upper limit
  54. GRB 231117A: Mondy optical observations
  55. GRB 231118A: REM optical afterglow detection
  56. GRB 231117A: Chandra afterglow detection
  57. GRB 231117A: LDT Confirmation of Optical Fading
  58. GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
  59. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  60. GRB 231118A: MeerLICHT afterglow detection
  61. GRB 231117A: OHP/T120 optical observations
  62. GRB 231118A: VLT/X-shooter redshift
  63. GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
  64. GRB 231117A: MAAO 0.7-m telescope optical upper limit
  65. GRB 231117A: AKO Follow-Up Observation
  66. GRB 231117A: 10 GHz VLA detection
  67. GRB 231118A: Las Cumbres optical detection
  68. GRB 231118A: LCOGT Optical Observations
  69. GRB 231118A: MASTER OT observation
  70. GRB 231118A: Skynet Optical Afterglow Discovery
  71. GRB 231117A: ePESSTO+ host galaxy redshift confirmation
  72. GRB 231117A: Keck spectroscopy of afterglow candidate
  73. GRB 231115A: Wendelstein Optical/Infrared Observations
  74. GRB 231115A: JinShan optical upper limits
  75. GRB 231117A: GIT optical follow-up
  76. GRB 231117A: LT observations consistent with fading
  77. GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
  78. GRB 231117A: REM optical and NIR early-time observations
  79. GRB 231117A: AKO Optical Upper Limit
  80. GRB 231117A: ATLAS non-detection of an optical counterpart
  81. GRB 231115A : OHP/T120 optical upper limit
  82. GRB 231115A: optical observations from INAF observatories
  83. GRB 231117A : MITSuME Akeno optical upper limits
  84. GRB 231117A: GOTO optical upper limits
  85. GRB231115A: Liverpool Telescope imaging
  86. GRB 231115A: NuSTAR Follow-Up Observations
  87. GRB 231115A: Swift-XRT and Swift-UVOT observations
  88. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  89. GRB 231115A: Gaoyazi/GOT follow-up and archival observations
  90. GRB 231115A: archival Chandra X-ray observations
  91. GRB 231115A: Kinder observations with Lulin observatory
  92. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  93. GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
  94. GRB 231106A: TESS identification of candidate optical counterpart
  95. GRB 231115A: MASTER optical observations
  96. GRB 231115A: archival HST observations
  97. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  98. GRB 231111A: Xinglong-2.16m optical observations
  99. GRB 231111A: TNG tentative redshift
  100. GRB 231111A: Leavitt Observatory optical observations

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