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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"

20119 results found.

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

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