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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"

31745 results found.

  1. GRB 070520A, Swift-BAT refined analysis
  2. GRB 070520A: Swift-XRT refined analysis
  3. GRB 070518: TNG observations
  4. GRB 070520: Xinglong EST optical Upper Limit
  5. VLA observation of GRB 070518
  6. GRB 070518: Swift-XRT refined analysis
  7. GRB 070517: Gemini optical imaging
  8. GRB070518: UVOT refined analysis
  9. GRB 070518, Swift-BAT refined analysis
  10. GRB 070518: OT confirmed form Xinglong TNT observation
  11. GRB070517: Swift-XRT Refined Analysis
  12. GRB 070517, Swift-BAT refined analysis
  13. GRB 070509: objects inside XRT error circle
  14. GRB070419A: optical observations
  15. GRB 070419A, Deep LBT photometry
  16. GRB 070509: Swift/UVOT Upper Limits
  17. Konus-Wind and Konus-A observation of GRB 070508
  18. Swift-BAT trigger 278987 is not a GRB
  19. GRB070509: Swift-XRT Refined Analysis
  20. RHESSI Spectrum of GRB070508
  21. GRB 070508: OA fading and tentative redshift
  22. GRB 070509, Swift-BAT refined analysis
  23. GRB 070508: Suzaku/WAM observation of the prompt emission
  24. GRB 070509: REM observations
  25. GRB 070509: ROTSE-III Optical Limits
  26. GRB070508: Swift/UVOT Observations
  27. GRB 070508, SMARTS optical afterglow observation
  28. GRB 070508, Swift-BAT refined analysis
  29. GRB 070508: Multicolor optical observations and possible redshift limit
  30. GRB 070508: Swift-XRT refined analysis
  31. GRB 070508: Optical observation limiting magnitude
  32. GRB 070508: Optical afterglow detection
  33. GRB 070508: REM observations
  34. GRB070412: MAGIC telescope GeV observation
  35. Swift-BAT trigger 278809 is not a GRB
  36. GRB 070506: VLT redshift
  37. GRB070506: Swift/UVOT Observations
  38. GRB070506: Swift XRT refined analysis
  39. GRB 070506, Swift-BAT Refined Analysis
  40. GRB 070412, deep LBT imaging
  41. GRB 070429A: Swift XRT further analysis
  42. GRB070429B: VLT observations
  43. GRB 070429A: optical observations
  44. GRB070429B: position correction
  45. GRB 070309: Swift-XRT afterglow confirmation
  46. GRB070429B: possible host galaxy detection
  47. VLA observation of GRB 070429B
  48. Swift/UVOT observations of GRB070429B
  49. GRB 070429B, Swift-BAT refined analysis
  50. Swift/UVOT observations of GRB070429A
  51. GRB 070429A: Swift XRT refined analysis
  52. GRB 070429A, Swift-BAT refined analysis
  53. GRB 070429B: Swift XRT refined analysis
  54. GRB 070429B: ROTSE-III Optical Limits
  55. GRB 070429: ROTSE-III Optical Limits
  56. GRB 070427, Swift-BAT Refined Analysis
  57. LT monitoring of GRB070412
  58. GRB 070411, further deep LBT photometry
  59. GRB 070411: Late-time Keck imaging
  60. GRB070419B: Suzaku WAM observation of the prompt emission
  61. GRB 070420, SMARTS optical/IR afterglow observations
  62. GRB 070411, deep LBT photometry
  63. Konus-Wind observation of GRB 070420
  64. GRB 070411: break in the optical light curve
  65. GRB 070420 Swift-BAT Refined Analysis
  66. GRB070419A: Kuiper Optical detection
  67. GRB070419a: Swift UVOT observations
  68. GRB 070419A: MARGE Observations
  69. GRB 070420: optical rebrightening observed at Mt. John
  70. GRB 070420: Swift XRT refined analysis
  71. GRB070420: Swift UVOT continuing observations
  72. GRB 070411: BART early limit
  73. GRB 070420: Faulkes Telescope South Observations
  74. GBR 070419A: Swift/XRT refined analysis
  75. GRB 070420: NIR and optical afterglow confirmed
  76. GRB 070419A: MITSuME Okayama Observations
  77. GRB 070419A: Early Super-LOTIS Observations
  78. GRB 070419B, Swift-BAT refined analysis
  79. GRB 070419A Swift-BAT Refined Analysis
  80. GRB070419B: Confirmation of Optical Transient
  81. GRB 070419A: RAPTOR Detection of Early Emission
  82. GRB 070419B: Swift XRT refined analysis
  83. GRB 070419: Keck/LRIS Absorption Redshift
  84. GRB 070419A, Optical observations
  85. GRB 070411: Deep VLT detection
  86. GRB 070419A: SARA observations
  87. GRB 070419A: NAYUTA Optical Observation
  88. GRB 070419A: Faulkes Telescope North Optical Observations
  89. GRB 070419B optical afterglow candidate
  90. GRB 070419A: Optical and IR observations with KANATA
  91. GRB 070419B: optical afterglow candidate
  92. GRB070419A, optical observation
  93. Infrared detection of GRB070419A with UKIRT
  94. GRB070330: Correction to UVOT position
  95. GRB 070419: P60 Confirmation of Optical Afterglow
  96. GRB 070419 optical afterglow candidate
  97. GRB 070419A: ROTSE-III Optical Limits
  98. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  99. GRB 070418: Optical and IR observations with KANATA
  100. GRB 070406: Swift XRT refined analysis

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