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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"

35349 results found.

  1. GRB050824: First 2 hours of power low optical decay?
  2. GRB 050826: Swift XRT position
  3. GRB050826: Swift-BAT detection of a long burst
  4. GRB050824: MASTER final analysis of the OT observations
  5. Possible GRB050825:MASTER optical observations
  6. Swift-BAT trigger 152038 is definitely not a GRB
  7. Swift-BAT trigger 152038 is probably not a GRB
  8. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  9. GRB050824, I-band imaging
  10. GRB050824: Radio Observations
  11. GRB 050824: Spectroscopic redshift from the VLT
  12. GRB 050822: refined XRT analysis
  13. GRB 050824: XRT refined analysis and possible afterglow detection
  14. GRB 050824: BAT refined analysis of a soft weak burst
  15. GRB050824: MASTER:OT decay
  16. GRB050824: MASTER observation OT
  17. GRB050805a: MASTER optical candidat
  18. GRB 050824: ROTSE-III Optical Limits
  19. GRB050824: Swift-BAT detection of a burst
  20. GRB 050824 optical candidate
  21. GRB050820A: RTT150 optical observations
  22. GRB050820a: PROMPT RcIc Observations
  23. GRB050815: Maidanak optical observation
  24. XRF050509c: Radio upper limits from GMRT
  25. VLT/UVES spectroscopy of GRB050820
  26. GRB 050820A BAT observations of second, larger episode of emission
  27. GRB050813: Maidanak I-band observations
  28. GRB 050822: Swift-BAT refined analysis
  29. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  30. GRB050820B at FRAM
  31. GRB050820A: RTT150 optical observations
  32. GRB 050820a - corrections to GCN 3846
  33. Swift/UVOT UV Photometry of GRB 050820B
  34. GRB 050822: ROTSE-III Prompt Optical Limits
  35. GRB 050822: Swift detection of a long burst
  36. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  37. GRB050820A: Radio Observation
  38. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  39. GRB050820a BVRcIc field photometry
  40. GRB 050820a: NIR Observations by WIRO
  41. GRB 050820B: Swift XRT position
  42. GRB050820B: Refined analysis of the Swift-BAT burst
  43. GRB050820B: BAT-Swift detection of a bright GRB
  44. GRB050820: refined XRT analysis
  45. GRB 050820: Early RAPTOR detections
  46. GRB 050820 Swift-BAT refined analysis
  47. GRB 050820: P60 Temporal Decay Index
  48. GRB 050820: High Resolution Spectroscopy from Keck
  49. GRB050819: RTT150 optical observations
  50. GRB 050820: Swift detection of a GRB
  51. GRB 050819 Swift-BAT refined analysis
  52. GRB050819: Swift XRT position
  53. GRB050819: Swift-BAT detection of a weak burst
  54. Swift-BAT trigger 150993 is not a GRB
  55. Swift Trigger 150823 is HETE J1900.1-2455
  56. GRB 050817: Optical observations
  57. GRB 050815: Radio Observation
  58. GRB050814: Radio Observation
  59. GRB050817: Negative Optical Observations
  60. GRB 050814: continued fading
  61. GRB 050813: Radio Observations
  62. GRB050815: Refined analysis of the Swift-BAT burst
  63. GRB 050815: ROTSE-III Optical Limits
  64. GRB050815: Swift XRT afterglow localization
  65. GRB 050730: Third Epoch WSRT Radio Observations
  66. GRB050814: Fading red source
  67. GRB 050813: Gemini Spectra Revisited
  68. GRB 050813: Non-fading of afterglow candidate
  69. GRB 050814: XRT refined analysis
  70. GRB050814: Refined analysis of the Swift-BAT burst
  71. GRB050813: Gemini Imaging
  72. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  73. GRB 050814: Swift XRT Afterglow Localization
  74. GRB 050814: Swift detection of a burst
  75. GRB 050813: Magellan detection of a high redshift galaxy cluster
  76. GRB050813: RTT150 optical observations
  77. GRB 050813: I-band observations
  78. GRB050813, SDSS pre-burst observations
  79. GRB 050813: KAIT optical limit
  80. GRB 050813: Swift-BAT refined analysis
  81. GRB 050813: Photometry of object in XRT error circle
  82. GRB 050813: Swift XRT afterglow localization
  83. RBO GRB 050714A and GRB 050716 observations
  84. GRB 050813: Possible Short Swift-BAT GRB
  85. Swift-BAT trigger 150131 is not a GRB
  86. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  87. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  88. GRB050803: CrAO optical observations, no OT candidate
  89. GRB 050730: WSRT Radio Observations
  90. GRB 050803: PROMPT BVRcIc Observations
  91. GRB 050807: ROTSE-III Optical Limits
  92. GRB 050730, optical observation
  93. GRB050805b: CrAO optical limit
  94. GRB050805a : Null detection report
  95. GRB050730, optical observations
  96. GRB050803, optical observations
  97. Swift-BAT trigger 149118 is very likely not a GRB
  98. Retraction of Swift Trigger 149131 (GRB 050805B)
  99. GRB 050805b: OHP optical limits
  100. GRB 050805b: TAROT optical limits

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