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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"

20882 results found.

  1. GRB050824: Maidanak optical limits
  2. GRB 050827: Swift-BAT refined analysis
  3. GRB050827: Swift-BAT detection of a burst
  4. Subaru Observations of GRB050724
  5. GRB 050826: Swift XRT preliminary analysis results
  6. GRB050826: Swift/UVOT early upper limits
  7. GRB050826: Swift-BAT detection of a long burst
  8. GRB050824: CORRECTION to UVOT observing times
  9. GRB050824: Swift/UVOT detection of fading afterglow
  10. GRB 050824: BAT refined analysis of a soft weak burst
  11. GRB050824: MASTER:OT decay
  12. GRB050824: MASTER observation OT
  13. GRB050805a: MASTER optical candidat
  14. GRB 050824: ROTSE-III Optical Limits
  15. GRB050824: Swift-BAT detection of a burst
  16. GRB050820a: PROMPT RcIc Observations
  17. XRF050509c: Radio upper limits from GMRT
  18. GRB050822: Swift/UVOT upper limits
  19. GRB050813: Maidanak I-band observations
  20. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  21. GRB050820B at FRAM
  22. Swift/UVOT UV Photometry of GRB 050820B
  23. GRB 050822: ROTSE-III Prompt Optical Limits
  24. GRB 050822: Swift detection of a long burst
  25. GRB050820a BVRcIc field photometry
  26. GRB050820B XMM-Newton observation
  27. GRB 050820a: NIR Observations by WIRO
  28. GRB 050820B: Swift XRT position
  29. GRB050820: refined XRT analysis
  30. GRB050819: refined XRT analysis
  31. GRB 050820: Swift detection of a GRB
  32. GRB050820: Optical afterglow from P60
  33. GRB050819: Swift-BAT detection of a weak burst
  34. Swift Trigger 150823 is HETE J1900.1-2455
  35. GRB 050817: Optical observations
  36. GRB 050814: continued fading
  37. GRB050815: Optical afterglow detection by Swift UVOT
  38. GRB 050813: Radio Observations
  39. GRB 050815: ROTSE-III Optical Limits
  40. GRB050815: Swift-BAT detection of a burst
  41. GRB050814: Fading red source
  42. GRB050814: P60 Optical Afterglow Candidate
  43. GRB 050813: Non-fading of afterglow candidate
  44. GRB050814: SWIFT/UVOT observation
  45. GRB050814: Refined analysis of the Swift-BAT burst
  46. GRB 050814: Swift XRT Afterglow Localization
  47. GRB 050814: Swift detection of a burst
  48. GRB 050813: Magellan detection of a high redshift galaxy cluster
  49. GRB050813, SDSS pre-burst observations
  50. GRB 050813: Swift-BAT refined analysis
  51. GRB050813: SWIFT/UVOT observation
  52. GRB 050813: Swift XRT afterglow localization
  53. GRB 050813: Possible Short Swift-BAT GRB
  54. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  55. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  56. GRB050803: CrAO optical observations, no OT candidate
  57. Detection of an intermediate burst from SGR 1806-20 on August 8
  58. GRB 050803: PROMPT BVRcIc Observations
  59. GRB 050807: ROTSE-III Optical Limits
  60. GRB 050730, optical observation
  61. GRB050805b: CrAO optical limit
  62. GRB050803, optical observations
  63. Retraction of Swift Trigger 149131 (GRB 050805B)
  64. GRB 050805b: OHP optical limits
  65. GRB 050805b: TAROT optical limits
  66. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  67. Swift-BAT trigger 149118 is probably not a GRB
  68. GRB050802: TNG optical observations
  69. GRB050803: Radio Observation
  70. GRB 050803: RTT150 optical observations
  71. GRB050801: Radio Observation
  72. GRB050730: Radio Detection
  73. GRB050803: CrAO optical observations, possible OT candidate
  74. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  75. GRB 050803: Keck Observations
  76. GRB 050803: Swift-BAT refined analysis
  77. GRB 050802.422: Fading of the afterglow and detection of the host
  78. GRB 050803, optical observations
  79. GRB 050803: early Swift XRT analysis results
  80. GRB 050803: TAROT optical limits
  81. GRB050803: Swift-BAT detection of a very long burst
  82. GCN GRB observation 050713A
  83. GRB 050802: Swift/UVOT optical and UV detections
  84. GRB050802 radio non-detection
  85. GRB 050730: OHP optical observations
  86. GRB 050802: Swift/UVOT observations
  87. GRB 050802 : Lulin Optical follow-up observation
  88. GRB 050802: Swift-BAT refined analysis
  89. GRB050801: Optical photometry and decay index
  90. GRB 050802: Swift Gamma-ray Burst
  91. GCN 050801: early Swift XRT analysis results
  92. GRB 050801: Swift-BAT refined analysis
  93. GRB050801: Swift-BAT detection of a burst
  94. GRB 050730: early TAROT optical observations
  95. GRB 050726: PROMPT Rc Observations
  96. Swift/UVOT photometry of GRB050730
  97. GRB 050730, spectra and optical photometry
  98. GRB050730: Refined BAT analysis of the Swift-BAT burst
  99. GRB 050730: Swift XRT afterglow observations
  100. GRB 050730 XMM-Newton observation

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