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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"

35948 results found.

  1. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  2. GRB050803: CrAO optical observations, no OT candidate
  3. GRB 050730: WSRT Radio Observations
  4. GRB 050803: PROMPT BVRcIc Observations
  5. GRB 050807: ROTSE-III Optical Limits
  6. GRB 050730, optical observation
  7. GRB050805b: CrAO optical limit
  8. GRB050805a : Null detection report
  9. GRB050730, optical observations
  10. GRB050803, optical observations
  11. Swift-BAT trigger 149118 is very likely not a GRB
  12. Retraction of Swift Trigger 149131 (GRB 050805B)
  13. GRB 050805b: OHP optical limits
  14. GRB 050805b: TAROT optical limits
  15. GRB050805b: MASTER optical observations
  16. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  17. GRB050805a: MASTER optical candidat
  18. Swift-BAT trigger 149118 is probably not a GRB
  19. GRB 050803: RTT150 optical observations
  20. GRB050803: CrAO optical observations, possible OT candidate
  21. GRB 050803: Keck Observations
  22. GRB 050803: Swift-BAT refined analysis
  23. GRB 050802.422: Fading of the afterglow and detection of the host
  24. GRB050803: MASTER further analys
  25. GRB 050803, optical observations
  26. GRB 050803: Magellan Observations
  27. GRB 050803: early Swift XRT analysis results
  28. GRB 050803: TAROT optical limits
  29. GRB050803: MASTER optical observations
  30. GRB050802: Tentative absorption redshift
  31. GCN GRB observation 050713A
  32. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  33. GRB 050802: Swift/UVOT optical and UV detections
  34. GRB050802: CrAO optical observations
  35. GRB050801: Unchanged decay slope
  36. GRB 050730: OHP optical observations
  37. GRB 050802: early Swift XRT analysis results
  38. GRB 050802: Swift/UVOT observations
  39. GRB 050802 : Lulin Optical follow-up observation
  40. GRB 050802: Swift-BAT refined analysis
  41. GRB050801: Optical photometry and decay index
  42. GRB 050802: XRT position
  43. GRB 050802: Swift Gamma-ray Burst
  44. GRB 050730: Preliminary Analysis of MIKE Spectrum
  45. GCN 050801: early Swift XRT analysis results
  46. GRB 050801: Swift-BAT refined analysis
  47. GRB 050801, SMARTS optical/IR afterglow observations
  48. GRB 050801, afterglow observations
  49. GRB 050730, corrected photometry and break?
  50. GRB 050801: ROTSE-III Early Afterglow Break
  51. GRB050801: Swift-BAT detection of a burst
  52. GRB 050801: ROTSE-III Detection of Possible Counterpart
  53. GRB 050730: XRT refined analysis
  54. Correction to GCN Circ 3476 on GRB050525A
  55. GRB 050730: early TAROT optical observations
  56. GRB 050726: PROMPT Rc Observations
  57. GRB 050730: RTT150 optical observations
  58. GRB 050730, spectra and optical photometry
  59. GRB050730: Refined BAT analysis of the Swift-BAT burst
  60. GRB 050730: Swift XRT afterglow observations
  61. GRB 050730 XMM-Newton observation
  62. GRB 050730: PROMPT VRcIc Observations
  63. GRB050730, afterglow observations
  64. GRB050730: confirmation of redshift
  65. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  66. GRB 050730, SMARTS optical/IR afterglow observations
  67. GRB 050730 : Planned XMM-Newton observation
  68. GRB050730: Liverpool Telescope optical observations
  69. GRB 050730, optical candidate
  70. GRB050730: Swift-BAT detection of a weak burst
  71. GRB 050713A: Swift XRT extended light curve
  72. GRB 050709: PROMPT Rc Observations
  73. GRB050713b: Maidanak optical observations
  74. GRB 050724: Secure Host Redshift from Keck
  75. GRB 050724: WHT optical observations
  76. GRB 050724: Chandra Observations of the X-ray Afterglow
  77. GRB050713: analysis of the XMM-Newton observation
  78. GRB 050724, SMARTS optical/IR afterglow observations
  79. GRB 050726, SMARTS optical/IR observations
  80. Swift-BAT trigger 147918 is not a real GRB
  81. GRB 050727: RTT150 optical observations
  82. GRB050727: KAIT optical limit
  83. GRB050709: Second Epoch Chandra Observation
  84. GRB 050726: PROMPT Rc Observations
  85. GRB050709: Second Epoch Chandra Observation
  86. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  87. GRB 050726: early Swift XRT analysis results
  88. GRB 050724: Optical Variability in Nearby Galaxy
  89. GRB 050724: J-band observations
  90. GRB 050724: GMOS Imaging and Spectroscopy
  91. GRB 050724: SWIFT XRT refined position
  92. GRB 050724: spectroscopy of object in the XRT error circle
  93. GRB 050724: Optical limit
  94. GRB 050724: optical and near-IR observations
  95. GRB 050724: Optical imaging/astrometry
  96. GRB 050724: RTT150 optical observations
  97. GRB 050724: Swift/UVOT Upper Limit
  98. GRB 050724: early Swift XRT analysis results
  99. GRB 050724 : Lulin early R-band monitoring observations
  100. GRB050724: Refined analysis of the Swift-BAT possible short burst

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