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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"

36158 results found.

  1. RBO GRB 050714A and GRB 050716 observations
  2. GRB 050813: Possible Short Swift-BAT GRB
  3. Swift-BAT trigger 150131 is not a GRB
  4. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  5. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  6. GRB050803: CrAO optical observations, no OT candidate
  7. GRB 050730: WSRT Radio Observations
  8. GRB 050803: PROMPT BVRcIc Observations
  9. GRB 050807: ROTSE-III Optical Limits
  10. GRB 050730, optical observation
  11. GRB050805b: CrAO optical limit
  12. GRB050805a : Null detection report
  13. GRB050730, optical observations
  14. GRB050803, optical observations
  15. Swift-BAT trigger 149118 is very likely not a GRB
  16. Retraction of Swift Trigger 149131 (GRB 050805B)
  17. GRB 050805b: OHP optical limits
  18. GRB 050805b: TAROT optical limits
  19. GRB050805b: MASTER optical observations
  20. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  21. GRB050805a: MASTER optical candidat
  22. Swift-BAT trigger 149118 is probably not a GRB
  23. GRB 050803: RTT150 optical observations
  24. GRB050803: CrAO optical observations, possible OT candidate
  25. GRB 050803: Keck Observations
  26. GRB 050803: Swift-BAT refined analysis
  27. GRB 050802.422: Fading of the afterglow and detection of the host
  28. GRB050803: MASTER further analys
  29. GRB 050803, optical observations
  30. GRB 050803: Magellan Observations
  31. GRB 050803: early Swift XRT analysis results
  32. GRB 050803: TAROT optical limits
  33. GRB050803: MASTER optical observations
  34. GRB050802: Tentative absorption redshift
  35. GCN GRB observation 050713A
  36. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  37. GRB 050802: Swift/UVOT optical and UV detections
  38. GRB050802: CrAO optical observations
  39. GRB050801: Unchanged decay slope
  40. GRB 050730: OHP optical observations
  41. GRB 050802: early Swift XRT analysis results
  42. GRB 050802: Swift/UVOT observations
  43. GRB 050802 : Lulin Optical follow-up observation
  44. GRB 050802: Swift-BAT refined analysis
  45. GRB050801: Optical photometry and decay index
  46. GRB 050802: XRT position
  47. GRB 050802: Swift Gamma-ray Burst
  48. GRB 050730: Preliminary Analysis of MIKE Spectrum
  49. GCN 050801: early Swift XRT analysis results
  50. GRB 050801: Swift-BAT refined analysis
  51. GRB 050801, SMARTS optical/IR afterglow observations
  52. GRB 050801, afterglow observations
  53. GRB 050730, corrected photometry and break?
  54. GRB 050801: ROTSE-III Early Afterglow Break
  55. GRB050801: Swift-BAT detection of a burst
  56. GRB 050801: ROTSE-III Detection of Possible Counterpart
  57. GRB 050730: XRT refined analysis
  58. Correction to GCN Circ 3476 on GRB050525A
  59. GRB 050730: early TAROT optical observations
  60. GRB 050726: PROMPT Rc Observations
  61. GRB 050730: RTT150 optical observations
  62. GRB 050730, spectra and optical photometry
  63. GRB050730: Refined BAT analysis of the Swift-BAT burst
  64. GRB 050730: Swift XRT afterglow observations
  65. GRB 050730 XMM-Newton observation
  66. GRB 050730: PROMPT VRcIc Observations
  67. GRB050730, afterglow observations
  68. GRB050730: confirmation of redshift
  69. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  70. GRB 050730, SMARTS optical/IR afterglow observations
  71. GRB 050730 : Planned XMM-Newton observation
  72. GRB050730: Liverpool Telescope optical observations
  73. GRB 050730, optical candidate
  74. GRB050730: Swift-BAT detection of a weak burst
  75. GRB 050713A: Swift XRT extended light curve
  76. GRB 050709: PROMPT Rc Observations
  77. GRB050713b: Maidanak optical observations
  78. GRB 050724: Secure Host Redshift from Keck
  79. GRB 050724: WHT optical observations
  80. GRB 050724: Chandra Observations of the X-ray Afterglow
  81. GRB050713: analysis of the XMM-Newton observation
  82. GRB 050724, SMARTS optical/IR afterglow observations
  83. GRB 050726, SMARTS optical/IR observations
  84. Swift-BAT trigger 147918 is not a real GRB
  85. GRB 050727: RTT150 optical observations
  86. GRB050727: KAIT optical limit
  87. GRB050709: Second Epoch Chandra Observation
  88. GRB 050726: PROMPT Rc Observations
  89. GRB050709: Second Epoch Chandra Observation
  90. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  91. GRB 050726: early Swift XRT analysis results
  92. GRB 050724: Optical Variability in Nearby Galaxy
  93. GRB 050724: J-band observations
  94. GRB 050724: GMOS Imaging and Spectroscopy
  95. GRB 050724: SWIFT XRT refined position
  96. GRB 050724: spectroscopy of object in the XRT error circle
  97. GRB 050724: Optical limit
  98. GRB 050724: optical and near-IR observations
  99. GRB 050724: Optical imaging/astrometry
  100. GRB 050724: RTT150 optical observations

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