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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"

35949 results found.

  1. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  2. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  3. GRB050803: CrAO optical observations, no OT candidate
  4. GRB 050730: WSRT Radio Observations
  5. GRB 050803: PROMPT BVRcIc Observations
  6. GRB 050807: ROTSE-III Optical Limits
  7. GRB 050730, optical observation
  8. GRB050805b: CrAO optical limit
  9. GRB050805a : Null detection report
  10. GRB050730, optical observations
  11. GRB050803, optical observations
  12. Swift-BAT trigger 149118 is very likely not a GRB
  13. Retraction of Swift Trigger 149131 (GRB 050805B)
  14. GRB 050805b: OHP optical limits
  15. GRB 050805b: TAROT optical limits
  16. GRB050805b: MASTER optical observations
  17. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  18. GRB050805a: MASTER optical candidat
  19. Swift-BAT trigger 149118 is probably not a GRB
  20. GRB 050803: RTT150 optical observations
  21. GRB050803: CrAO optical observations, possible OT candidate
  22. GRB 050803: Keck Observations
  23. GRB 050803: Swift-BAT refined analysis
  24. GRB 050802.422: Fading of the afterglow and detection of the host
  25. GRB050803: MASTER further analys
  26. GRB 050803, optical observations
  27. GRB 050803: Magellan Observations
  28. GRB 050803: early Swift XRT analysis results
  29. GRB 050803: TAROT optical limits
  30. GRB050803: MASTER optical observations
  31. GRB050802: Tentative absorption redshift
  32. GCN GRB observation 050713A
  33. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  34. GRB 050802: Swift/UVOT optical and UV detections
  35. GRB050802: CrAO optical observations
  36. GRB050801: Unchanged decay slope
  37. GRB 050730: OHP optical observations
  38. GRB 050802: early Swift XRT analysis results
  39. GRB 050802: Swift/UVOT observations
  40. GRB 050802 : Lulin Optical follow-up observation
  41. GRB 050802: Swift-BAT refined analysis
  42. GRB050801: Optical photometry and decay index
  43. GRB 050802: XRT position
  44. GRB 050802: Swift Gamma-ray Burst
  45. GRB 050730: Preliminary Analysis of MIKE Spectrum
  46. GCN 050801: early Swift XRT analysis results
  47. GRB 050801: Swift-BAT refined analysis
  48. GRB 050801, SMARTS optical/IR afterglow observations
  49. GRB 050801, afterglow observations
  50. GRB 050730, corrected photometry and break?
  51. GRB 050801: ROTSE-III Early Afterglow Break
  52. GRB050801: Swift-BAT detection of a burst
  53. GRB 050801: ROTSE-III Detection of Possible Counterpart
  54. GRB 050730: XRT refined analysis
  55. Correction to GCN Circ 3476 on GRB050525A
  56. GRB 050730: early TAROT optical observations
  57. GRB 050726: PROMPT Rc Observations
  58. GRB 050730: RTT150 optical observations
  59. GRB 050730, spectra and optical photometry
  60. GRB050730: Refined BAT analysis of the Swift-BAT burst
  61. GRB 050730: Swift XRT afterglow observations
  62. GRB 050730 XMM-Newton observation
  63. GRB 050730: PROMPT VRcIc Observations
  64. GRB050730, afterglow observations
  65. GRB050730: confirmation of redshift
  66. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  67. GRB 050730, SMARTS optical/IR afterglow observations
  68. GRB 050730 : Planned XMM-Newton observation
  69. GRB050730: Liverpool Telescope optical observations
  70. GRB 050730, optical candidate
  71. GRB050730: Swift-BAT detection of a weak burst
  72. GRB 050713A: Swift XRT extended light curve
  73. GRB 050709: PROMPT Rc Observations
  74. GRB050713b: Maidanak optical observations
  75. GRB 050724: Secure Host Redshift from Keck
  76. GRB 050724: WHT optical observations
  77. GRB 050724: Chandra Observations of the X-ray Afterglow
  78. GRB050713: analysis of the XMM-Newton observation
  79. GRB 050724, SMARTS optical/IR afterglow observations
  80. GRB 050726, SMARTS optical/IR observations
  81. Swift-BAT trigger 147918 is not a real GRB
  82. GRB 050727: RTT150 optical observations
  83. GRB050727: KAIT optical limit
  84. GRB050709: Second Epoch Chandra Observation
  85. GRB 050726: PROMPT Rc Observations
  86. GRB050709: Second Epoch Chandra Observation
  87. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  88. GRB 050726: early Swift XRT analysis results
  89. GRB 050724: Optical Variability in Nearby Galaxy
  90. GRB 050724: J-band observations
  91. GRB 050724: GMOS Imaging and Spectroscopy
  92. GRB 050724: SWIFT XRT refined position
  93. GRB 050724: spectroscopy of object in the XRT error circle
  94. GRB 050724: Optical limit
  95. GRB 050724: optical and near-IR observations
  96. GRB 050724: Optical imaging/astrometry
  97. GRB 050724: RTT150 optical observations
  98. GRB 050724: Swift/UVOT Upper Limit
  99. GRB 050724: early Swift XRT analysis results
  100. GRB 050724 : Lulin early R-band monitoring observations

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