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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"

20391 results found.

  1. GRB 050908: Swift detection of a burst
  2. GRB 050906: Optical observations at the Very Large Telescope
  3. GRB050904: CrAO optical observations
  4. GRB 050904: Subaru Optical Spectroscopy
  5. GRB 050906: Swift XRT upper limit
  6. GRB 050904: Keck I-band Imaging
  7. GRB050906: P60 Observations
  8. GRB 050904: photometric redshift
  9. GRB 050904: Swift/UVOT observations
  10. GRB 050904: NIR object inside the XRT error box
  11. GRB050904: Optical Observations
  12. GRB050904: P60 Observations
  13. GRB 050904: TAROT optical limits
  14. GRB050904: Swift-BAT detection of a probable burst
  15. GRB 050827: P200 NIR Observations
  16. GRB050827: Swift/UVOT upper limits
  17. GRB050824: Maidanak optical limits
  18. GRB 050827: Swift-BAT refined analysis
  19. Subaru Observations of GRB050724
  20. GRB 050826: BAT refined analysis
  21. GRB050826: Swift/UVOT early upper limits
  22. GRB050826: Swift-BAT detection of a long burst
  23. GRB050824, I-band imaging
  24. XRF050509c: Radio upper limits from GMRT
  25. GRB050822: Swift/UVOT upper limits
  26. GRB050813: Maidanak I-band observations
  27. GRB 050822: Swift-BAT refined analysis
  28. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  29. GRB050820B at FRAM
  30. Swift/UVOT UV Photometry of GRB 050820B
  31. GRB 050822: Swift detection of a long burst
  32. GRB050820a BVRcIc field photometry
  33. GRB050820B XMM-Newton observation
  34. GRB 050820B: Swift XRT position
  35. GRB050820: refined XRT analysis
  36. GRB050819: refined XRT analysis
  37. GRB 050820: Swift detection of a GRB
  38. GRB 050819 Swift-BAT refined analysis
  39. GRB050819: Swift-BAT detection of a weak burst
  40. Swift Trigger 150823 is HETE J1900.1-2455
  41. GRB 050817: Optical observations
  42. GRB050817: Swift-BAT Detection of a burst
  43. GRB 050814: continued fading
  44. GRB050815: Refined analysis of the Swift-BAT burst
  45. GRB 050815: ROTSE-III Optical Limits
  46. GRB050815: Swift-BAT detection of a burst
  47. GRB050814: Fading red source
  48. GRB050814: P60 Optical Afterglow Candidate
  49. GRB 050813: Non-fading of afterglow candidate
  50. GRB 050814: XRT refined analysis
  51. GRB050814: SWIFT/UVOT observation
  52. GRB 050814: Swift XRT Afterglow Localization
  53. GRB 050814: Swift detection of a burst
  54. GRB 050813: Magellan detection of a high redshift galaxy cluster
  55. GRB050813, SDSS pre-burst observations
  56. GRB050813: SWIFT/UVOT observation
  57. GRB 050813: Swift XRT afterglow localization
  58. GRB050803: CrAO optical observations, no OT candidate
  59. GRB050805b: CrAO optical limit
  60. GRB050803, optical observations
  61. Retraction of Swift Trigger 149131 (GRB 050805B)
  62. GRB 050805b: OHP optical limits
  63. GRB 050805b: TAROT optical limits
  64. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  65. GRB050802: TNG optical observations
  66. GRB050803: Radio Observation
  67. GRB 050803: RTT150 optical observations
  68. GRB050801: Radio Observation
  69. GRB050730: Radio Detection
  70. GRB 050803: Keck Observations
  71. GRB 050802.422: Fading of the afterglow and detection of the host
  72. GRB 050803: TAROT optical limits
  73. GRB050803: Swift-BAT detection of a very long burst
  74. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  75. GRB 050802: Swift/UVOT optical and UV detections
  76. GRB050802 radio non-detection
  77. GRB 050730: OHP optical observations
  78. GRB050801: Optical photometry and decay index
  79. GRB 050802: Swift Gamma-ray Burst
  80. GCN 050801: early Swift XRT analysis results
  81. GRB 050730, corrected photometry and break?
  82. GRB 050730: early TAROT optical observations
  83. GRB 050730, spectra and optical photometry
  84. GRB 050730 XMM-Newton observation
  85. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  86. GRB050730: Swift-BAT detection of a weak burst
  87. GRB 050713A: Swift XRT extended light curve
  88. GRB 050724: WHT optical observations
  89. GRB050713: analysis of the XMM-Newton observation
  90. GRB050709: Second Epoch Chandra Observation
  91. GRB050709: Second Epoch Chandra Observation
  92. GRB 050724: Optical Variability in Nearby Galaxy
  93. GRB 050724: J-band observations
  94. GRB 050724: GMOS Imaging and Spectroscopy
  95. GRB050724: Radio Observation
  96. GRB 050724: Swift/UVOT Upper Limit
  97. GRB 050724: possible host galaxy in DSS
  98. GRB050721A: optical decay
  99. GRB 050721: optical afterglow confirmed
  100. GRB050714b: Radio Observation

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