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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"
  1. RHESSI Spectrum of GRB070508
  2. GRB 070508: OA fading and tentative redshift
  3. GRB 070509, Swift-BAT refined analysis
  4. GRB 070508: Suzaku/WAM observation of the prompt emission
  5. GRB 070509: REM observations
  6. GRB 070509: Swift detection of a burst
  7. GRB 070509: ROTSE-III Optical Limits
  8. GRB070508: Swift/UVOT Observations
  9. GRB 070508, SMARTS optical afterglow observation
  10. GRB 070508, Swift-BAT refined analysis
  11. GRB 070508: Multicolor optical observations and possible redshift limit
  12. GRB 070508: Swift-XRT refined analysis
  13. GRB 070508: Optical observation limiting magnitude
  14. GRB 070508: Optical afterglow detection
  15. GRB 070508: REM observations
  16. GRB 070508: TAROT La Silla observatory optical observations
  17. GRB 070508: Swift detection of an intense burst with an optical counterpart
  18. GRB070412: MAGIC telescope GeV observation
  19. Swift-BAT trigger 278809 is not a GRB
  20. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  21. GRB 070506: VLT redshift
  22. GRB070506: Swift/UVOT Observations
  23. GRB070506: Swift XRT refined analysis
  24. GRB 070506, Swift-BAT Refined Analysis
  25. GRB 070506: Swift detection of a burst with optical afterglow
  26. GRB 070412, deep LBT imaging
  27. GRB 070429A: Swift XRT further analysis
  28. GRB070429B: VLT observations
  29. GRB 070429A: optical observations
  30. GRB070429B: position correction
  31. GRB 070309: Swift-XRT afterglow confirmation
  32. GRB070429B: possible host galaxy detection
  33. VLA observation of GRB 070429B
  34. Swift/UVOT observations of GRB070429B
  35. GRB 070429B, Swift-BAT refined analysis
  36. Swift/UVOT observations of GRB070429A
  37. GRB 070429A: Swift XRT refined analysis
  38. GRB 070429A, Swift-BAT refined analysis
  39. GRB 070429A: optical and NIR observations
  40. GRB 070429B: Swift XRT refined analysis
  41. GRB 070429B: ROTSE-III Optical Limits
  42. GRB 070429B: Swift detection of a short burst
  43. GRB 070429: What's the temperature?
  44. GRB 070429: ROTSE-III Optical Limits
  45. GRB 070429: Swift detection of a burst
  46. GRB 070427, Swift-BAT Refined Analysis
  47. LT monitoring of GRB070412
  48. GRB 070427: Swift detection of a burst
  49. GRB 070411, further deep LBT photometry
  50. GRB 070411: Late-time Keck imaging
  51. GRB 070411 : Planned XMM-Newton observation
  52. GRB070419B: Suzaku WAM observation of the prompt emission
  53. GRB 070420, SMARTS optical/IR afterglow observations
  54. GRB 070411, deep LBT photometry
  55. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  56. Konus-Wind observation of GRB 070420
  57. GRB 070411: break in the optical light curve
  58. GRB 070420 Swift-BAT Refined Analysis
  59. GRB070419A: Kuiper Optical detection
  60. GRB070419a: Swift UVOT observations
  61. GRB 070419A: MARGE Observations
  62. GRB 070420: optical rebrightening observed at Mt. John
  63. GRB 070420: Swift XRT refined analysis
  64. GRB070420: Swift UVOT continuing observations
  65. GRB 070411: BART early limit
  66. GRB 070420: Faulkes Telescope South Observations
  67. GBR 070419A: Swift/XRT refined analysis
  68. GRB 070420: TAROT La Silla observatory optical observations
  69. GRB 070420: NIR and optical afterglow confirmed
  70. GRB 070420: Swift detection of a burst with optical afterglow
  71. GRB 070419A: MITSuME Okayama Observations
  72. GRB 070419A: Early Super-LOTIS Observations
  73. GRB 070419B, Swift-BAT refined analysis
  74. GRB 070419A Swift-BAT Refined Analysis
  75. GRB070419B: Confirmation of Optical Transient
  76. GRB 070419A: RAPTOR Detection of Early Emission
  77. GRB 070419B: Swift XRT refined analysis
  78. GRB 070419: Keck/LRIS Absorption Redshift
  79. GRB 070419B: optical afterglow confirmation
  80. GRB 070419A, Optical observations
  81. GRB 070411: Deep VLT detection
  82. GRB070419 - SDSS Pre-Burst Observations
  83. GRB 070419A: SARA observations
  84. GRB 070419A: NAYUTA Optical Observation
  85. GRB 070419A: Faulkes Telescope North Optical Observations
  86. GRB 070419B optical afterglow candidate
  87. GRB 070419A: Optical and IR observations with KANATA
  88. GRB 070419B: optical afterglow candidate
  89. GRB 070419A: Lulin Optical observation
  90. GRB070419A, optical observation
  91. Infrared detection of GRB070419A with UKIRT
  92. GRB 070419A: Kiso Optical observation
  93. GRB070330: Correction to UVOT position
  94. GRB 070419: P60 Confirmation of Optical Afterglow
  95. GRB 070419B: Swift detection of a burst
  96. GRB 070419 optical afterglow candidate
  97. GRB 070419A: ROTSE-III Optical Limits
  98. GRB 070419: Swift detection of a burst
  99. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  100. GRB 070418: Optical and IR observations with KANATA

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