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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"

22917 results found.

  1. GRB 050915: ROTSE-III optical limits
  2. GRB 050915: Swift detection of a GRB
  3. GRB050911: Upper limit on X-ray afterglow
  4. Swift-BAT trigger 155072 ground analysis
  5. Swift-BAT trigger 155072 is probably not a GRB
  6. GRB 050911: LCO limits on a variable source
  7. GRB 050911, optical content of Swift/XRT error box
  8. GRB050911: Swift-XRT position
  9. GRB 050911: z~0.16 cluster in the field
  10. GRB050911: Swift-BAT detection of a long burst
  11. GRB050908: detection of Swift/UVOT optical counterpart
  12. GRB 050910a: TAROT early optical limits
  13. GRB 050906: Possible X-ray Counterpart
  14. GRB050908: Swift/UVOT Early upper limits
  15. GRB050908 : Swift-XRT refined analysis
  16. GRB 050908: Optical observations
  17. GRB 050908: Swift detection of a burst
  18. GRB 050906: Optical observations at the Very Large Telescope
  19. GRB 050904 BAT refined analysis of complete data set
  20. GRB 050904: Subaru Optical Spectroscopy
  21. GRB 050906: Swift-BAT refined analysis
  22. GRB 050906: Swift XRT upper limit
  23. GRB 050904: Keck I-band Imaging
  24. GRB050906: P60 Observations
  25. GRB 050904: more VLT NIR observations
  26. GRB 050906: Swift/BAT Detection of a possible burst
  27. GRB 050904: photometric redshift
  28. GRB 050904: Swift/UVOT observations
  29. GRB 050904: NIR object inside the XRT error box
  30. GRB050904: Optical Observations
  31. GRB050904: P60 Observations
  32. GRB 050904: TAROT optical limits
  33. GRB050904: Swift-BAT detection of a probable burst
  34. GRB 050827: P200 NIR Observations
  35. GRB050827: Swift/UVOT upper limits
  36. GRB050824: Maidanak optical limits
  37. GRB 050827: Swift-BAT refined analysis
  38. GRB050827: Swift-BAT detection of a burst
  39. Subaru Observations of GRB050724
  40. GRB 050826: Swift XRT preliminary analysis results
  41. GRB050826: Swift/UVOT early upper limits
  42. GRB050826: Swift-BAT detection of a long burst
  43. GRB050824: CORRECTION to UVOT observing times
  44. GRB050824: Swift/UVOT detection of fading afterglow
  45. GRB 050824: BAT refined analysis of a soft weak burst
  46. GRB050824: MASTER:OT decay
  47. GRB050824: MASTER observation OT
  48. GRB050805a: MASTER optical candidat
  49. GRB 050824: ROTSE-III Optical Limits
  50. GRB050824: Swift-BAT detection of a burst
  51. GRB050820a: PROMPT RcIc Observations
  52. XRF050509c: Radio upper limits from GMRT
  53. GRB050822: Swift/UVOT upper limits
  54. GRB050813: Maidanak I-band observations
  55. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  56. GRB050820B at FRAM
  57. Swift/UVOT UV Photometry of GRB 050820B
  58. GRB 050822: ROTSE-III Prompt Optical Limits
  59. GRB 050822: Swift detection of a long burst
  60. GRB050820a BVRcIc field photometry
  61. GRB050820B XMM-Newton observation
  62. GRB 050820a: NIR Observations by WIRO
  63. GRB 050820B: Swift XRT position
  64. GRB050820: refined XRT analysis
  65. GRB050819: refined XRT analysis
  66. GRB 050820: Swift detection of a GRB
  67. GRB050820: Optical afterglow from P60
  68. GRB050819: Swift-BAT detection of a weak burst
  69. Swift Trigger 150823 is HETE J1900.1-2455
  70. GRB 050817: Optical observations
  71. GRB 050814: continued fading
  72. GRB050815: Optical afterglow detection by Swift UVOT
  73. GRB 050813: Radio Observations
  74. GRB 050815: ROTSE-III Optical Limits
  75. GRB050815: Swift-BAT detection of a burst
  76. GRB050814: Fading red source
  77. GRB050814: P60 Optical Afterglow Candidate
  78. GRB 050813: Non-fading of afterglow candidate
  79. GRB050814: SWIFT/UVOT observation
  80. GRB050814: Refined analysis of the Swift-BAT burst
  81. GRB 050814: Swift XRT Afterglow Localization
  82. GRB 050814: Swift detection of a burst
  83. GRB 050813: Magellan detection of a high redshift galaxy cluster
  84. GRB050813, SDSS pre-burst observations
  85. GRB 050813: Swift-BAT refined analysis
  86. GRB050813: SWIFT/UVOT observation
  87. GRB 050813: Swift XRT afterglow localization
  88. GRB 050813: Possible Short Swift-BAT GRB
  89. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  90. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  91. GRB050803: CrAO optical observations, no OT candidate
  92. Detection of an intermediate burst from SGR 1806-20 on August 8
  93. GRB 050803: PROMPT BVRcIc Observations
  94. GRB 050807: ROTSE-III Optical Limits
  95. GRB 050730, optical observation
  96. GRB050805b: CrAO optical limit
  97. GRB050803, optical observations
  98. Retraction of Swift Trigger 149131 (GRB 050805B)
  99. GRB 050805b: OHP optical limits
  100. GRB 050805b: TAROT optical limits

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