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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. GRB060526, optical observations
  2. GRB 051227 : WIDGET simultaneous optical observations
  3. GRB 051028 : WIDGET pre-trigger limit
  4. GRB060526: Optical counterpart from MIRO
  5. GRB 060526: RTT150 optical observations
  6. GRB060526: optical observations
  7. GRB 060526: SMARTS optical/IR afterglow observations
  8. GRB 060526: REM observations
  9. GRB 060526: RTT150 optical observations, afterglow flattening
  10. GRB 060526: Refined analysis of the Swift-BAT burst
  11. GRB 060526: RTT150 optical observations
  12. GRB060526, optical observations
  13. GRB 060526: Watcher Observations
  14. GRB060526 - SDSS Pre-burst Observations
  15. GRB 060526: Swift detection of a burst with x-ray and optical afterglow
  16. GRB 060413 : WIDGET simultaneous optical observations
  17. XMM-Newton observation of GRB060510b
  18. GRB060512: Late-Time P200 Observations
  19. GRB 060522: Swift-BAT Refined Analysis
  20. GRB 060522: REM NIR observations
  21. GRB 060522: TNG optical observations
  22. GRB 060522: Swift detection of a burst with possible optical afterglow
  23. GRB 060515: NIR observation
  24. GRB060515: P200 NIR Observations
  25. GRB 060515 BAT refined analysis
  26. GRB 060512: TAROT optical observation
  27. GRB 060515: Swift/UVOT Upper Limits
  28. GRB 060515: Swift/XRT position
  29. GRB 060515: Super-LOTIS Observations
  30. GRB 060515: TAROT optical observation
  31. GRB 060515: ROTSE-III Optical Limits
  32. GRB 060515: Swift detection of a burst
  33. GRB 060512: Subaru NIR observation
  34. GRB060512: Swift XRT Team refined analysis
  35. GRB 060512: 1.54m Kuiper Observations
  36. GRB 060512: Detection of NIR afterglow
  37. GRB 060512: P60 Observations
  38. GRB 060512: REM NIR observations
  39. GRB060512 - SDSS Pre-Burst Observations
  40. GRB 060512: Swift detection of a burst with an optical afterglow
  41. GRB 060505: X-ray afterglow - Correction -
  42. GRB 060505: X-ray afterglow
  43. Konus-Wind observation of GRB 060510A
  44. GRB060418: optical observations
  45. GRB060510 - SDSS Pre-Burst Observations
  46. GRB 060510B: Super-LOTIS Observations
  47. GRB 060510B: Swift detection of a burst
  48. GRB 060510: Swift detection of a burst with optical transient
  49. GRB060507: optical afterglow detection
  50. GRB060502B: improvement in the XRT afterglow position
  51. GRB 060507: Swift-BAT Refined Analysis
  52. GRB 060505: PROMPT Observations
  53. GRB 060507: Swift/UVOT Upper Limits
  54. GRB 060507: Swift XRT Team Refined Analysis
  55. GRB 060429: Suzaku WAM observation
  56. GRB060505: Swift/UVOT Observations
  57. GRB060425: new MASTER survey method
  58. GRB 060505: Swift XRT afterglow canditate position
  59. GRB 060502b: Second epoch Gemini observations
  60. GRB 060428B: spectroscopy
  61. GRB 060502B: optical observations
  62. GRB 060502B: AROMA refined photometric calibration
  63. GRB 060502B MDM Follow-up Observation
  64. GRB 060502b: Gemini imaging and spectroscopy
  65. GRB060502A, optical observation
  66. GRB 060502B: Swift/UVOT upper limits
  67. GRB 060502A: Swift/UVOT source detection
  68. GRB 060429: Refined IPN error box and Konus-Wind spectrum
  69. GRB060502B: Swift XRT Team refined analysis
  70. GRB 060501: P60 Observations and Candidate Retraction
  71. GRB 060502B: Xinglong optical observation
  72. GRB 060502B: MASTER optical observations
  73. GRB 060502: Swift-BAT refined analysis
  74. GRB060501: Swift UVOT followup observations
  75. GRB060502: Super-LOTIS Observations
  76. GRB 060502: P60 Afterglow Confirmation
  77. GRB 060502: Swift detection of a burst with an optical counterpart
  78. GRB060501: P60 imaging and afterglow candidate
  79. GRB 060501: Swift detection of a burst
  80. Konus-Wind observation of GRB 060427B
  81. GRB060428B - SDSS Pre-Burst Observations
  82. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  83. GRB060428B: Swift XRT Team refined analysis
  84. GRB 060427B: IPN localization of a short hard burst
  85. GRB 060428B: Xinglong I-band limit
  86. GRB 051117A: Bright host galaxy not confirmed
  87. GRB060428A: Swift/UVOT observations.
  88. GRB060428B, optical observation
  89. GRB 060428A: Refined analysis of the Swift-BAT burst
  90. GRB 060428b : Kiso R-band limit
  91. GRB 060428b: Optical afterglow candidate
  92. GRB 060428B: Swift detection of a burst
  93. GRB 060427: NIR observations
  94. GRB060427: Xinglong optical Observations
  95. GRB 060428: Swift detection of a burst
  96. GRB 060427: Swift/UVOT upper limits.
  97. GRB 060427: Refined analysis of the Swift-BAT burst
  98. GRB 060427, optical observation
  99. GRB 060427: Swift detection of a burst
  100. GRB 060425: IPN localization and KW spectrum of a short, hard burst

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