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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"

20361 results found.

  1. GRB 060502b: Second epoch Gemini observations
  2. GRB 060505: Swift-BAT detection of a weak burst
  3. GRB 060428B: spectroscopy
  4. GRB 060502B: optical observations
  5. GRB 060502B: AROMA refined photometric calibration
  6. GRB 060502B MDM Follow-up Observation
  7. GRB 060502b: Gemini imaging and spectroscopy
  8. GRB060502A, optical observation
  9. GRB 060502B: Swift/UVOT upper limits
  10. GRB 060502A: Swift/UVOT source detection
  11. GRB 060429: Refined IPN error box and Konus-Wind spectrum
  12. GRB 060502B: Refined analysis of the Swift-BAT short burst
  13. GRB060502B: Swift XRT Team refined analysis
  14. GRB 060501: P60 Observations and Candidate Retraction
  15. GRB 060502B: Xinglong optical observation
  16. GRB060501: Swift UVOT followup observations
  17. GRB 060502: P60 Afterglow Confirmation
  18. GRB 060502: Swift detection of a burst with an optical counterpart
  19. GRB060501: P60 imaging and afterglow candidate
  20. GRB 060501: Refined analysis of the Swift-BAT burst
  21. GRB060428B - SDSS Pre-Burst Observations
  22. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  23. GRB 060428A: PROMPT Observations
  24. GRB060428B: Swift XRT Team refined analysis
  25. GRB 060427B: IPN localization of a short hard burst
  26. GRB 060428B: Xinglong I-band limit
  27. GRB 051117A: Bright host galaxy not confirmed
  28. GRB060428A: Swift/UVOT observations.
  29. GRB060428B, optical observation
  30. GRB 060428b : Kiso R-band limit
  31. GRB 060428b: Optical afterglow candidate
  32. GRB 060428B: Swift detection of a burst
  33. GRB 060427: NIR observations
  34. GRB060427: Xinglong optical Observations
  35. GRB 060428: Swift detection of a burst
  36. GRB 060427: Swift/UVOT upper limits.
  37. GRB060427: Swift XRT Team refined analysis
  38. GRB060418: Swift XRT Team Further Refined Analysis
  39. GRB 060427, optical observation
  40. GRB 060427: Swift detection of a burst
  41. GRB 060424: Refined analysis of the Swift-BAT burst
  42. GRB060421: Swift/UVOT observations
  43. GRB(?) 060421: Swift detection of a burst
  44. GRB 060418: Radio Observations
  45. GRB060418, BVRcIc field calibration
  46. GRB060418: Swift/UVOT Observations
  47. GRB060418: Swift XRT Team Refined Analysis
  48. GRB060418 : LT optical afterglow observation
  49. GRB 060418: REM candidate afterglow
  50. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  51. GRB060413: Swift/UVOT upper limits
  52. GRB 060413: REM NIR Observations
  53. GRB 060413: Watcher UBVR observations
  54. GRB 060413: XRT refined analysis
  55. GRB 060403: MITSuME optical observation
  56. GRB060403: Optical Limit
  57. GRB060403: XRT refined analysis
  58. GRB 060403: Swift/UVOT upper limits
  59. SGR 1900+14: BAT observations
  60. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  61. GRB 060403: Swift detection of a burst
  62. HETE trigger H4044: RTT150 optical observations
  63. GRB060331: Swift/UVOT upper limits
  64. Swift XRT observations of the HETE transient H4043
  65. H4043, an unusual high-energy transient observed by HETE
  66. GRB 060322: LNA optical limit
  67. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  68. SGR 1900+14: Swift-BAT detection of a cluster of outbursts
  69. GRB 060323 : WIDGET simultaneous optical observations
  70. GRB 060323: Early optical observation at Xinglong
  71. GRB 060322: Confirmation of Swift XRT afterglow
  72. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  73. GRB060323: NOT optical observations
  74. GRB 060322: IAC80 optical observations
  75. GRB 060322: Swift XRT afterglow candidate
  76. GRB060323: P60 Observations
  77. GRB 060323: Swift/UVOT Observations
  78. GRB 060323: optical afterglow confirmed
  79. GRB060323: NOT observations
  80. GRB 060323: Optical Observations
  81. GRB 060323: optical observations at TNG
  82. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  83. GRB060323, optical observation
  84. GRB060323 - SDSS Pre-Burst Observations
  85. GRB 060323: Swift detection of a burst with a possible optical afterglow
  86. GRB 060218/SN 2006aj, LNA optical observation
  87. GRB060218: Refined photometric calibration of comparison stars
  88. GRB 060319: WHT K-band candidate afterglow
  89. GRB060319: Swift/UVOT upper limits
  90. GRB 060319: Swift-BAT refined analysis
  91. GRB 060319 optical observations at TNG
  92. GRB060319 : Liverpool Telescope optical limit
  93. GRB060319 - SDSS Pre-burst Observations
  94. GRB 060319: Swift detection of a burst
  95. GRB060313: Radio Observations
  96. GRB 060313: early afterglow NIR upper limits with REM
  97. GRB 060313: Swift/UVOT Observations
  98. GRB 060313: Swift-XRT team refined analysis
  99. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  100. GRB 060313, SMARTS optical counterpart?

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