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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"

20117 results found.

  1. GRB 060424: Refined analysis of the Swift-BAT burst
  2. GRB 060424: Swift detection of a burst
  3. GRB 060421: TTT Observations
  4. OT 060420: CONCAM detection of a candidate new magnitude 5 optical
  5. GRB060421: Swift/UVOT observations
  6. Konus-Wind observation of GRB 060418
  7. GRB(?) 060421: Swift detection of a burst
  8. GRB 060418: Radio Observations
  9. GRB060418, BVRcIc field calibration
  10. GRB060418: Swift/UVOT Observations
  11. GRB060418: Optical Observations
  12. GRB 060418: FRAM early afterglow observation
  13. VLT/UVES observations of GRB060418
  14. GRB 060418: PROMPT Detections
  15. GRB060418 : LT optical afterglow observation
  16. GRB 060418: REM candidate afterglow
  17. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  18. GRB060413: Swift/UVOT upper limits
  19. GRB 060413: REM NIR Observations
  20. GRB 060413: Swift detection of a burst
  21. GRB 060403 Optical observations
  22. GRB 060403: MITSuME optical observation
  23. GRB060403: Optical Limit
  24. GRB 060403: Swift/UVOT upper limits
  25. SGR 1900+14: BAT observations
  26. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  27. GRB 060403: Swift detection of a burst
  28. HETE trigger H4044: RTT150 optical observations
  29. GRB060331: Swift/UVOT upper limits
  30. Swift XRT observations of the HETE transient H4043
  31. HETE Trigger 4043: ROTSE-III Optical Limits
  32. H4043, an unusual high-energy transient observed by HETE
  33. GRB 060322: LNA optical limit
  34. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  35. GRB 060323 : WIDGET simultaneous optical observations
  36. GRB 060323: Early optical observation at Xinglong
  37. GRB 060322: Confirmation of Swift XRT afterglow
  38. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  39. GRB060323: NOT optical observations
  40. GRB 060322: IAC80 optical observations
  41. GRB 060322: Swift XRT afterglow candidate
  42. GRB060323: P60 Observations
  43. GRB 060323: Swift/UVOT Observations
  44. GRB 060323: optical afterglow confirmed
  45. GRB060323: NOT observations
  46. GRB 060323: Optical Observations
  47. GRB 060323: Refined analysis of the Swift-BAT burst
  48. GRB 060323: optical observations at TNG
  49. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  50. GRB 060322: Refined analysis of the Swift-BAT burst
  51. GRB060323, optical observation
  52. GRB060323 - SDSS Pre-Burst Observations
  53. GRB 060323: Swift detection of a burst with a possible optical afterglow
  54. GRB 060218/SN 2006aj, LNA optical observation
  55. GRB060218: Refined photometric calibration of comparison stars
  56. GRB 060319: WHT K-band candidate afterglow
  57. GRB060319: Swift/UVOT upper limits
  58. GRB 060319 optical observations at TNG
  59. GRB060319 : Liverpool Telescope optical limit
  60. GRB060319 - SDSS Pre-burst Observations
  61. GRB060319: Swift/XRT position
  62. GRB060313: Radio Observations
  63. GRB 060313: early afterglow NIR upper limits with REM
  64. Konus-Wind observation of GRB 060313
  65. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  66. GRB 060313: Swift/UVOT Observations
  67. GRB 060313, SMARTS optical/IR observations
  68. GRB060313: optical and near infrared observations with REM
  69. GRB 060313: Swift-BAT detection of a bright short hard burst
  70. GRB060218: SARA Observations of SN2006aj
  71. GRB 060312: Swift XRT team refined analysis
  72. GRB060306: APO Ks-band Imaging Observations
  73. GRB 060312: ROTSE-III Optical Limits
  74. Bright short hard GRB 060303: IPN localization and Konus spectrum
  75. GRB 060306: MAGNUM observations
  76. GRB060218: analysis of the XMM-Newton observation
  77. Swift/UVOT observations of GRB060306
  78. GRB 060306: Swift-XRT team refined analysis
  79. GRB 060306: Swift detection of a bright burst
  80. GRB060218: Ep,i - Eiso correlation
  81. GRB060223b: optical limit
  82. GRB 060223b: Swift/UVOT Upper Limits
  83. GRB 060218/SN 2006aj: K-380 optical observations
  84. GRB 060218/SN 2006aj, SMARTS optical/IR observations
  85. GRB200618: optical polarimetry and photometry
  86. GRB 060223B: Swift XRT possible afterglow
  87. GRB 060218/SN 2006aj: REM optical and near-infrared observations
  88. GRB 060218 : Radio upper limits from GMRT
  89. GRB 060223A:Xinglong optical limits
  90. GRB 060223a: Swift/UVOT refined analysis
  91. GRB 060223B: Swift detection of a bright burst
  92. GRB 060218: rebrightening
  93. GRB 060219: Swift-BAT refined analysis
  94. GRB 060218: Decline in r-band flux
  95. GRB060219: SARA Observations
  96. GRB 060219: Swift/UVOT Upper Limits
  97. GRB 051221B: Swift-XRT Team Refined Analysis
  98. GRB060218: Radio Afterglow Discovery
  99. GRB060219: SDSS pre-burst observations
  100. GRB 060219: Swift-BAT detection of a weak burst

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