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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"

3360 results found.

  1. GRB 060526: REM observations
  2. GRB 060526: Swift detection of a burst with x-ray and optical afterglow
  3. GRB 060515: ROTSE-III Optical Limits
  4. GRB 060510B: Super-LOTIS Observations
  5. GRB060502B: improvement in the XRT afterglow position
  6. GRB 060501: MDM Observations
  7. GRB060428B: optical observation
  8. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  9. GRB 060427B: MASTER optical observations
  10. GRB060428B: Swift XRT Team refined analysis
  11. GRB 060428B: KAIT observations
  12. GRB060428A: Swift/UVOT observations.
  13. GRB060428B, optical observation
  14. GRB 060421: TTT Observations
  15. GRB060418: Magellan/MIKE Spectroscopic Redshift
  16. GRB060413: Swift/UVOT upper limits
  17. SGR 1900+14: Swift detection of an outburst
  18. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  19. GRB060331: Swift/UVOT upper limits
  20. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  21. SGR 1900+14: Swift-BAT detection of a bright outburst
  22. GRB 060211A: optical observation
  23. GRB 060313: Possible optical counterpart
  24. GRB 060121: HST observations
  25. GRB 060218/SN 2006aj: ABT observations
  26. GRB 060218: rebrightening
  27. GRB060213: MASTER final result
  28. GRB060213:_MASTER_optical_observation
  29. GRB 050826: Optical Afterglow and Host Galaxy
  30. GRB060210: Swift/UVOT Upper Limits
  31. GRB 060211B: Swift-XRT Team refined analysis
  32. GRB 060206: WSRT Radio Observations
  33. GRB 060204A: ROSAT Pointing
  34. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  35. Swift-BAT trigger is GRB 060203
  36. GRB060202, optical observation
  37. GRB060105: refined analysis of the Suzaku observation
  38. GRB 060121: Swift/UVOT upper limits
  39. GRB 060116: UKIRT IR Observations
  40. GRB060115, optical observation
  41. GRB 060111B: MITSuME detection of optical afterglow
  42. GRB 060111B: TAROT optical observation
  43. GRB 060111B: Refined analysis of the Swift-BAT burst
  44. GRB 060110: IR Candidate Afterglow
  45. GRB 060110: Optical observation
  46. GRB 060110: Correction
  47. GRB 050110: IR Observations
  48. GRB060105: Swift detection of a bright long burst
  49. GRB 060102: MDM Observation
  50. GRB 060102: Swift-BAT refined analysis
  51. Time Correction to GRB 060102
  52. GRB 060102: Swift-BAT detection of a burst
  53. GRB051227: Radio Observations
  54. GRB 051227: Magellan r'-band Imaging/Astrometry
  55. GRB 051227: P60 Observations
  56. GRB 051227: MDM Observation
  57. GRB 051227: R-band object in the XRT error circle
  58. Swift detection of an RS CVn flare star
  59. GRB 051211A,optical observation
  60. GRB 051211B: Swift XRT confirmation of the afterglow
  61. GRB 051211B: Swift XRT Observations
  62. IPN observations of SGR1806-20
  63. GRB 051109B: GAO 150cm telescope Optical limit
  64. GRB 051028 Optical Observations
  65. GRB 051111: Radio afterglow
  66. GRB 051111a: IR photometry
  67. GRB 051109A: KAIT optical observations
  68. GRB 051105B (INTEGRAL 2701): Optical observation
  69. GRB051028:MASTER correction and final results
  70. GRB051028: optical observations
  71. GRB051028: Swift/UVOT upper limits
  72. GRB051028:MASTER observations
  73. GRB 051028 (=H3951): A GRB localized by HETE
  74. GRB051028:MASTER optical observations
  75. GRB051021A: Swift XRT refined analysis
  76. GRB051021: Swift/UVOT Upper Limits
  77. GRB051021: Swift XRT analysis
  78. GRB 051016B: Swift detection of a soft burst
  79. GRB051006: optical observations
  80. GRB050908: optical observations
  81. GRB050922C: UVES/VLT high resolution spectroscopy
  82. GRB 050922B,optical observation
  83. GRB050820B: analysis of the XMM-Newton observation
  84. GRB 050915a: IR Transient
  85. GRB 050915: IR Observations
  86. GRB050915: P60 Optical Observations
  87. GRB050915: XRT position
  88. Swift-BAT trigger 155072 ground analysis
  89. Swift-BAT trigger 155072 is probably not a GRB
  90. GRB050914: XRT position probably due to cosmic ray
  91. GRB 050904 BAT refined analysis of complete data set
  92. GRB050904: Swift-BAT detection of a probable burst
  93. GRB 050827: P200 NIR Observations
  94. GRB 050827: Optical Limit
  95. GRB050827: RTT150 optical observations
  96. GRB050827: Swift-BAT detection of a burst
  97. GRB 050824: ROTSE-III Optical Limits
  98. GRB 050820B: Swift XRT position
  99. GRB050815: Swift XRT afterglow localization
  100. GRB050815: Swift-BAT detection of a burst

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