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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

15985 results found.

  1. GRB 070509: ROTSE-III Optical Limits
  2. GRB 070508, SMARTS optical afterglow observation
  3. GRB 070508: Multicolor optical observations and possible redshift limit
  4. GRB 070508: Swift-XRT refined analysis
  5. GRB 070508: Optical observation limiting magnitude
  6. GRB 070508: Optical afterglow detection
  7. GRB 070508: REM observations
  8. GRB 070508: TAROT La Silla observatory optical observations
  9. GRB 070508: Swift detection of an intense burst with an optical counterpart
  10. GRB070506: Swift XRT refined analysis
  11. GRB 070506: Swift detection of a burst with optical afterglow
  12. GRB 070412, deep LBT imaging
  13. GRB 070429A: Swift XRT further analysis
  14. GRB 070429A: optical observations
  15. GRB 070429A: Swift XRT refined analysis
  16. GRB 070429A: optical and NIR observations
  17. GRB 070429B: ROTSE-III Optical Limits
  18. GRB 070429: ROTSE-III Optical Limits
  19. GRB 070420, SMARTS optical/IR afterglow observations
  20. GRB 070411: break in the optical light curve
  21. GRB070419A: Kuiper Optical detection
  22. GRB 070420: optical rebrightening observed at Mt. John
  23. GRB 070420: Swift XRT refined analysis
  24. GRB070420: Swift UVOT continuing observations
  25. GRB 070411: BART early limit
  26. GRB 070420: Faulkes Telescope South Observations
  27. GBR 070419A: Swift/XRT refined analysis
  28. GRB 070420: TAROT La Silla observatory optical observations
  29. GRB 070420: NIR and optical afterglow confirmed
  30. GRB 070420: Swift detection of a burst with optical afterglow
  31. GRB 070419A: MITSuME Okayama Observations
  32. GRB 070419A Swift-BAT Refined Analysis
  33. GRB070419B: Confirmation of Optical Transient
  34. GRB 070419A: RAPTOR Detection of Early Emission
  35. GRB 070419B: Swift XRT refined analysis
  36. GRB 070419: Keck/LRIS Absorption Redshift
  37. GRB 070419B: optical afterglow confirmation
  38. GRB 070419A, Optical observations
  39. GRB 070419A: NAYUTA Optical Observation
  40. GRB 070419A: Faulkes Telescope North Optical Observations
  41. GRB 070419B optical afterglow candidate
  42. GRB 070419A: Optical and IR observations with KANATA
  43. GRB 070419B: optical afterglow candidate
  44. GRB 070419A: Lulin Optical observation
  45. GRB070419A, optical observation
  46. GRB 070419A: Kiso Optical observation
  47. GRB070330: Correction to UVOT position
  48. GRB 070419: P60 Confirmation of Optical Afterglow
  49. GRB 070419 optical afterglow candidate
  50. GRB 070419A: ROTSE-III Optical Limits
  51. GRB 070418: Optical and IR observations with KANATA
  52. GRB 070318, SMARTS optical/IR afterglow observations
  53. GRB 070412 Liverpool Telescope optical limit
  54. GRB 070411: Optical photometry at Crni Vrh
  55. GRB 070412: Optical observations at Crni Vrh
  56. GRB 070411: OA redshift
  57. GRB 070412: Swift-XRT refined position
  58. GRB 070412: IAC80 optical afterglow candidate
  59. GRB 070411: IAC80 optical observations
  60. GRB 070411 : Liverpool Telescope Observations
  61. GRB 070411: Optical observations at Crni Vrh
  62. GRB 070411: ROTSE-III Detection of Optical Counterpart
  63. GRB 070411: Swift detection of a burst with optical afterglow
  64. GRB 070406: Swift XRT team further analysis
  65. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  66. GRB 070406: Correction to the optical candidate in GCN6253
  67. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  68. GRB 070406: Optical candidate
  69. GRB 070406: The exprosure time of Xinglong TNT optical Upper Limit
  70. GRB 070406: Xinglong TNT optical Upper Limit
  71. GRB 070311, deep optical photometry
  72. GRB 070330, SMARTS optical/IR observations
  73. GRB 070330: TAROT La Silla observatory optical observations
  74. GRB070220: optical observations
  75. GRB070208: optical observations
  76. GRB070223: confirmation of nIR and optical afterglow
  77. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  78. GRB 070311, deep optical photometry
  79. GRB 070318: Gemini + Magellan spectra
  80. GRB070318: Swift-XRT refined analysis
  81. GRB 070318: Swift/UVOT Continued Observations
  82. GRB 070318: Swift detection of a burst with an optical afterglow
  83. GRB 070311: Late Central Engine Activity Optical Flare??
  84. GRB 070311: MDM Optical Monitoring
  85. GRB 070311: Tautenburg sees afterglow fading
  86. GRB 070311: Optical observation.
  87. GRB 070311: Optical Brightening
  88. GRB 070311: MDM Optical Follow-up
  89. GRB 070311: RAPTOR Detection of Optical Emission
  90. GRB 070311: MDM Optical Detection
  91. GRB 070311: MITSuME Okayama Optical Observation
  92. GRB 070311: Swift-XRT refined analysis
  93. GRB 070311: REM candidate afterglow
  94. GRB060901: Candidate optical afterglow
  95. GRB 070125: Chandra X-ray Confirmation of Jet Break
  96. GRB 070306, optical observation
  97. GRB 070125: X-ray light curve analysis
  98. GRB 070306: ART-3 early optical and near infrared constraints
  99. GRB 070306: Optical and IR observations with KANATA
  100. GRB 070125, deep late-time optical observation

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