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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"

36149 results found.

  1. GRB 050730, optical observation
  2. GRB050805b: CrAO optical limit
  3. GRB050805a : Null detection report
  4. GRB050730, optical observations
  5. GRB050803, optical observations
  6. Swift-BAT trigger 149118 is very likely not a GRB
  7. Retraction of Swift Trigger 149131 (GRB 050805B)
  8. GRB 050805b: OHP optical limits
  9. GRB 050805b: TAROT optical limits
  10. GRB050805b: MASTER optical observations
  11. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  12. GRB050805a: MASTER optical candidat
  13. Swift-BAT trigger 149118 is probably not a GRB
  14. GRB 050803: RTT150 optical observations
  15. GRB050803: CrAO optical observations, possible OT candidate
  16. GRB 050803: Keck Observations
  17. GRB 050803: Swift-BAT refined analysis
  18. GRB 050802.422: Fading of the afterglow and detection of the host
  19. GRB050803: MASTER further analys
  20. GRB 050803, optical observations
  21. GRB 050803: Magellan Observations
  22. GRB 050803: early Swift XRT analysis results
  23. GRB 050803: TAROT optical limits
  24. GRB050803: MASTER optical observations
  25. GRB050802: Tentative absorption redshift
  26. GCN GRB observation 050713A
  27. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  28. GRB 050802: Swift/UVOT optical and UV detections
  29. GRB050802: CrAO optical observations
  30. GRB050801: Unchanged decay slope
  31. GRB 050730: OHP optical observations
  32. GRB 050802: early Swift XRT analysis results
  33. GRB 050802: Swift/UVOT observations
  34. GRB 050802 : Lulin Optical follow-up observation
  35. GRB 050802: Swift-BAT refined analysis
  36. GRB050801: Optical photometry and decay index
  37. GRB 050802: XRT position
  38. GRB 050802: Swift Gamma-ray Burst
  39. GRB 050730: Preliminary Analysis of MIKE Spectrum
  40. GCN 050801: early Swift XRT analysis results
  41. GRB 050801: Swift-BAT refined analysis
  42. GRB 050801, SMARTS optical/IR afterglow observations
  43. GRB 050801, afterglow observations
  44. GRB 050730, corrected photometry and break?
  45. GRB 050801: ROTSE-III Early Afterglow Break
  46. GRB050801: Swift-BAT detection of a burst
  47. GRB 050801: ROTSE-III Detection of Possible Counterpart
  48. GRB 050730: XRT refined analysis
  49. Correction to GCN Circ 3476 on GRB050525A
  50. GRB 050730: early TAROT optical observations
  51. GRB 050726: PROMPT Rc Observations
  52. GRB 050730: RTT150 optical observations
  53. GRB 050730, spectra and optical photometry
  54. GRB050730: Refined BAT analysis of the Swift-BAT burst
  55. GRB 050730: Swift XRT afterglow observations
  56. GRB 050730 XMM-Newton observation
  57. GRB 050730: PROMPT VRcIc Observations
  58. GRB050730, afterglow observations
  59. GRB050730: confirmation of redshift
  60. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  61. GRB 050730, SMARTS optical/IR afterglow observations
  62. GRB 050730 : Planned XMM-Newton observation
  63. GRB050730: Liverpool Telescope optical observations
  64. GRB 050730, optical candidate
  65. GRB050730: Swift-BAT detection of a weak burst
  66. GRB 050713A: Swift XRT extended light curve
  67. GRB 050709: PROMPT Rc Observations
  68. GRB050713b: Maidanak optical observations
  69. GRB 050724: Secure Host Redshift from Keck
  70. GRB 050724: WHT optical observations
  71. GRB 050724: Chandra Observations of the X-ray Afterglow
  72. GRB050713: analysis of the XMM-Newton observation
  73. GRB 050724, SMARTS optical/IR afterglow observations
  74. GRB 050726, SMARTS optical/IR observations
  75. Swift-BAT trigger 147918 is not a real GRB
  76. GRB 050727: RTT150 optical observations
  77. GRB050727: KAIT optical limit
  78. GRB050709: Second Epoch Chandra Observation
  79. GRB 050726: PROMPT Rc Observations
  80. GRB050709: Second Epoch Chandra Observation
  81. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  82. GRB 050726: early Swift XRT analysis results
  83. GRB 050724: Optical Variability in Nearby Galaxy
  84. GRB 050724: J-band observations
  85. GRB 050724: GMOS Imaging and Spectroscopy
  86. GRB 050724: SWIFT XRT refined position
  87. GRB 050724: spectroscopy of object in the XRT error circle
  88. GRB 050724: Optical limit
  89. GRB 050724: optical and near-IR observations
  90. GRB 050724: Optical imaging/astrometry
  91. GRB 050724: RTT150 optical observations
  92. GRB 050724: Swift/UVOT Upper Limit
  93. GRB 050724: early Swift XRT analysis results
  94. GRB 050724 : Lulin early R-band monitoring observations
  95. GRB050724: Refined analysis of the Swift-BAT possible short burst
  96. GRB 050724: possible host galaxy in DSS
  97. Swift-BAT trigger 147325 is not due to a real GRB
  98. GRB050723: XRT distributed coordinates are not related to the burst
  99. GRB 050721: early afterglow light curve
  100. GRB 050721A: Swift-BAT refined analysis

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