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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"

22085 results found.

  1. GRB050904: Swift-BAT detection of a probable burst
  2. GRB 050827: P200 NIR Observations
  3. GRB050827: Swift/UVOT upper limits
  4. GRB050824: Maidanak optical limits
  5. GRB 050827: Swift-BAT refined analysis
  6. GRB050827: Swift-BAT detection of a burst
  7. Subaru Observations of GRB050724
  8. GRB 050826: Swift XRT preliminary analysis results
  9. GRB050826: Swift/UVOT early upper limits
  10. GRB050826: Swift-BAT detection of a long burst
  11. GRB050824: CORRECTION to UVOT observing times
  12. GRB050824: Swift/UVOT detection of fading afterglow
  13. GRB 050824: BAT refined analysis of a soft weak burst
  14. GRB050824: MASTER:OT decay
  15. GRB050824: MASTER observation OT
  16. GRB050805a: MASTER optical candidat
  17. GRB 050824: ROTSE-III Optical Limits
  18. GRB050824: Swift-BAT detection of a burst
  19. GRB050820a: PROMPT RcIc Observations
  20. XRF050509c: Radio upper limits from GMRT
  21. GRB050822: Swift/UVOT upper limits
  22. GRB050813: Maidanak I-band observations
  23. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  24. GRB050820B at FRAM
  25. Swift/UVOT UV Photometry of GRB 050820B
  26. GRB 050822: ROTSE-III Prompt Optical Limits
  27. GRB 050822: Swift detection of a long burst
  28. GRB050820a BVRcIc field photometry
  29. GRB050820B XMM-Newton observation
  30. GRB 050820a: NIR Observations by WIRO
  31. GRB 050820B: Swift XRT position
  32. GRB050820: refined XRT analysis
  33. GRB050819: refined XRT analysis
  34. GRB 050820: Swift detection of a GRB
  35. GRB050820: Optical afterglow from P60
  36. GRB050819: Swift-BAT detection of a weak burst
  37. Swift Trigger 150823 is HETE J1900.1-2455
  38. GRB 050817: Optical observations
  39. GRB 050814: continued fading
  40. GRB050815: Optical afterglow detection by Swift UVOT
  41. GRB 050813: Radio Observations
  42. GRB 050815: ROTSE-III Optical Limits
  43. GRB050815: Swift-BAT detection of a burst
  44. GRB050814: Fading red source
  45. GRB050814: P60 Optical Afterglow Candidate
  46. GRB 050813: Non-fading of afterglow candidate
  47. GRB050814: SWIFT/UVOT observation
  48. GRB050814: Refined analysis of the Swift-BAT burst
  49. GRB 050814: Swift XRT Afterglow Localization
  50. GRB 050814: Swift detection of a burst
  51. GRB 050813: Magellan detection of a high redshift galaxy cluster
  52. GRB050813, SDSS pre-burst observations
  53. GRB 050813: Swift-BAT refined analysis
  54. GRB050813: SWIFT/UVOT observation
  55. GRB 050813: Swift XRT afterglow localization
  56. GRB 050813: Possible Short Swift-BAT GRB
  57. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  58. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  59. GRB050803: CrAO optical observations, no OT candidate
  60. Detection of an intermediate burst from SGR 1806-20 on August 8
  61. GRB 050803: PROMPT BVRcIc Observations
  62. GRB 050807: ROTSE-III Optical Limits
  63. GRB 050730, optical observation
  64. GRB050805b: CrAO optical limit
  65. GRB050803, optical observations
  66. Retraction of Swift Trigger 149131 (GRB 050805B)
  67. GRB 050805b: OHP optical limits
  68. GRB 050805b: TAROT optical limits
  69. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  70. Swift-BAT trigger 149118 is probably not a GRB
  71. GRB050802: TNG optical observations
  72. GRB050803: Radio Observation
  73. GRB 050803: RTT150 optical observations
  74. GRB050801: Radio Observation
  75. GRB050730: Radio Detection
  76. GRB050803: CrAO optical observations, possible OT candidate
  77. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  78. GRB 050803: Keck Observations
  79. GRB 050803: Swift-BAT refined analysis
  80. GRB 050802.422: Fading of the afterglow and detection of the host
  81. GRB 050803, optical observations
  82. GRB 050803: early Swift XRT analysis results
  83. GRB 050803: TAROT optical limits
  84. GRB050803: Swift-BAT detection of a very long burst
  85. GCN GRB observation 050713A
  86. GRB 050802: Swift/UVOT optical and UV detections
  87. GRB050802 radio non-detection
  88. GRB 050730: OHP optical observations
  89. GRB 050802: Swift/UVOT observations
  90. GRB 050802 : Lulin Optical follow-up observation
  91. GRB 050802: Swift-BAT refined analysis
  92. GRB050801: Optical photometry and decay index
  93. GRB 050802: Swift Gamma-ray Burst
  94. GCN 050801: early Swift XRT analysis results
  95. GRB 050801: Swift-BAT refined analysis
  96. GRB050801: Swift-BAT detection of a burst
  97. GRB 050730: early TAROT optical observations
  98. GRB 050726: PROMPT Rc Observations
  99. Swift/UVOT photometry of GRB050730
  100. GRB 050730, spectra and optical photometry

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