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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"

16155 results found.

  1. GRB 070518: MARGE Observations
  2. GRB 070518: optical observation
  3. GRB070521: NIR observations
  4. GRB070520B: NIR observations
  5. GRB 070521, optical observation
  6. GROND upper limits of GRB 070521
  7. GRB070518: Optical/NIR observation
  8. GRB 070521: optical limit by Pi of the Sky
  9. GRB 070521: TAROT La Silla observatory optical observations
  10. GRB 070520A: MITSuME Akeno optical upper limits
  11. GRB 070518: TNG observations
  12. GRB 070520: Xinglong EST optical Upper Limit
  13. GRB 070517: Gemini optical imaging
  14. GRB070518: OSN observation
  15. GRB 070518: Swift detection of a burst with optical afterglow
  16. GRB 070517: Optical search
  17. GRB070419A: optical observations
  18. GRB 070508: OA fading and tentative redshift
  19. GRB 070509: REM observations
  20. GRB 070509: ROTSE-III Optical Limits
  21. GRB 070508, SMARTS optical afterglow observation
  22. GRB 070508: Multicolor optical observations and possible redshift limit
  23. GRB 070508: Swift-XRT refined analysis
  24. GRB 070508: Optical observation limiting magnitude
  25. GRB 070508: Optical afterglow detection
  26. GRB 070508: REM observations
  27. GRB 070508: TAROT La Silla observatory optical observations
  28. GRB 070508: Swift detection of an intense burst with an optical counterpart
  29. GRB070506: Swift XRT refined analysis
  30. GRB 070506: Swift detection of a burst with optical afterglow
  31. GRB 070412, deep LBT imaging
  32. GRB 070429A: Swift XRT further analysis
  33. GRB 070429A: optical observations
  34. GRB 070429A: Swift XRT refined analysis
  35. GRB 070429A: optical and NIR observations
  36. GRB 070429B: ROTSE-III Optical Limits
  37. GRB 070429: ROTSE-III Optical Limits
  38. GRB 070420, SMARTS optical/IR afterglow observations
  39. GRB 070411: break in the optical light curve
  40. GRB070419A: Kuiper Optical detection
  41. GRB 070420: optical rebrightening observed at Mt. John
  42. GRB 070420: Swift XRT refined analysis
  43. GRB070420: Swift UVOT continuing observations
  44. GRB 070411: BART early limit
  45. GRB 070420: Faulkes Telescope South Observations
  46. GBR 070419A: Swift/XRT refined analysis
  47. GRB 070420: TAROT La Silla observatory optical observations
  48. GRB 070420: NIR and optical afterglow confirmed
  49. GRB 070420: Swift detection of a burst with optical afterglow
  50. GRB 070419A: MITSuME Okayama Observations
  51. GRB 070419A Swift-BAT Refined Analysis
  52. GRB070419B: Confirmation of Optical Transient
  53. GRB 070419A: RAPTOR Detection of Early Emission
  54. GRB 070419B: Swift XRT refined analysis
  55. GRB 070419: Keck/LRIS Absorption Redshift
  56. GRB 070419B: optical afterglow confirmation
  57. GRB 070419A, Optical observations
  58. GRB 070419A: NAYUTA Optical Observation
  59. GRB 070419A: Faulkes Telescope North Optical Observations
  60. GRB 070419B optical afterglow candidate
  61. GRB 070419A: Optical and IR observations with KANATA
  62. GRB 070419B: optical afterglow candidate
  63. GRB 070419A: Lulin Optical observation
  64. GRB070419A, optical observation
  65. GRB 070419A: Kiso Optical observation
  66. GRB070330: Correction to UVOT position
  67. GRB 070419: P60 Confirmation of Optical Afterglow
  68. GRB 070419 optical afterglow candidate
  69. GRB 070419A: ROTSE-III Optical Limits
  70. GRB 070418: Optical and IR observations with KANATA
  71. GRB 070318, SMARTS optical/IR afterglow observations
  72. GRB 070412 Liverpool Telescope optical limit
  73. GRB 070411: Optical photometry at Crni Vrh
  74. GRB 070412: Optical observations at Crni Vrh
  75. GRB 070411: OA redshift
  76. GRB 070412: Swift-XRT refined position
  77. GRB 070412: IAC80 optical afterglow candidate
  78. GRB 070411: IAC80 optical observations
  79. GRB 070411 : Liverpool Telescope Observations
  80. GRB 070411: Optical observations at Crni Vrh
  81. GRB 070411: ROTSE-III Detection of Optical Counterpart
  82. GRB 070411: Swift detection of a burst with optical afterglow
  83. GRB 070406: Swift XRT team further analysis
  84. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  85. GRB 070406: Correction to the optical candidate in GCN6253
  86. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  87. GRB 070406: Optical candidate
  88. GRB 070406: The exprosure time of Xinglong TNT optical Upper Limit
  89. GRB 070406: Xinglong TNT optical Upper Limit
  90. GRB 070311, deep optical photometry
  91. GRB 070330, SMARTS optical/IR observations
  92. GRB 070330: TAROT La Silla observatory optical observations
  93. GRB070220: optical observations
  94. GRB070208: optical observations
  95. GRB070223: confirmation of nIR and optical afterglow
  96. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  97. GRB 070311, deep optical photometry
  98. GRB 070318: Gemini + Magellan spectra
  99. GRB070318: Swift-XRT refined analysis
  100. GRB 070318: Swift/UVOT Continued Observations

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