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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"

36040 results found.

  1. GRB050824: Radio Observations
  2. GRB 050824: Spectroscopic redshift from the VLT
  3. GRB 050822: refined XRT analysis
  4. GRB 050824: XRT refined analysis and possible afterglow detection
  5. GRB 050824: BAT refined analysis of a soft weak burst
  6. GRB050824: MASTER:OT decay
  7. GRB050824: MASTER observation OT
  8. GRB050805a: MASTER optical candidat
  9. GRB 050824: ROTSE-III Optical Limits
  10. GRB050824: Swift-BAT detection of a burst
  11. GRB 050824 optical candidate
  12. GRB050820A: RTT150 optical observations
  13. GRB050820a: PROMPT RcIc Observations
  14. GRB050815: Maidanak optical observation
  15. XRF050509c: Radio upper limits from GMRT
  16. VLT/UVES spectroscopy of GRB050820
  17. GRB 050820A BAT observations of second, larger episode of emission
  18. GRB050813: Maidanak I-band observations
  19. GRB 050822: Swift-BAT refined analysis
  20. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  21. GRB050820B at FRAM
  22. GRB050820A: RTT150 optical observations
  23. GRB 050820a - corrections to GCN 3846
  24. Swift/UVOT UV Photometry of GRB 050820B
  25. GRB 050822: ROTSE-III Prompt Optical Limits
  26. GRB 050822: Swift detection of a long burst
  27. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  28. GRB050820A: Radio Observation
  29. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  30. GRB050820a BVRcIc field photometry
  31. GRB 050820a: NIR Observations by WIRO
  32. GRB 050820B: Swift XRT position
  33. GRB050820B: Refined analysis of the Swift-BAT burst
  34. GRB050820B: BAT-Swift detection of a bright GRB
  35. GRB050820: refined XRT analysis
  36. GRB 050820: Early RAPTOR detections
  37. GRB 050820 Swift-BAT refined analysis
  38. GRB 050820: P60 Temporal Decay Index
  39. GRB 050820: High Resolution Spectroscopy from Keck
  40. GRB050819: RTT150 optical observations
  41. GRB 050820: Swift detection of a GRB
  42. GRB 050819 Swift-BAT refined analysis
  43. GRB050819: Swift XRT position
  44. GRB050819: Swift-BAT detection of a weak burst
  45. Swift-BAT trigger 150993 is not a GRB
  46. Swift Trigger 150823 is HETE J1900.1-2455
  47. GRB 050817: Optical observations
  48. GRB 050815: Radio Observation
  49. GRB050814: Radio Observation
  50. GRB050817: Negative Optical Observations
  51. GRB 050814: continued fading
  52. GRB 050813: Radio Observations
  53. GRB050815: Refined analysis of the Swift-BAT burst
  54. GRB 050815: ROTSE-III Optical Limits
  55. GRB050815: Swift XRT afterglow localization
  56. GRB 050730: Third Epoch WSRT Radio Observations
  57. GRB050814: Fading red source
  58. GRB 050813: Gemini Spectra Revisited
  59. GRB 050813: Non-fading of afterglow candidate
  60. GRB 050814: XRT refined analysis
  61. GRB050814: Refined analysis of the Swift-BAT burst
  62. GRB050813: Gemini Imaging
  63. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  64. GRB 050814: Swift XRT Afterglow Localization
  65. GRB 050814: Swift detection of a burst
  66. GRB 050813: Magellan detection of a high redshift galaxy cluster
  67. GRB050813: RTT150 optical observations
  68. GRB 050813: I-band observations
  69. GRB050813, SDSS pre-burst observations
  70. GRB 050813: KAIT optical limit
  71. GRB 050813: Swift-BAT refined analysis
  72. GRB 050813: Photometry of object in XRT error circle
  73. GRB 050813: Swift XRT afterglow localization
  74. RBO GRB 050714A and GRB 050716 observations
  75. GRB 050813: Possible Short Swift-BAT GRB
  76. Swift-BAT trigger 150131 is not a GRB
  77. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  78. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  79. GRB050803: CrAO optical observations, no OT candidate
  80. GRB 050730: WSRT Radio Observations
  81. GRB 050803: PROMPT BVRcIc Observations
  82. GRB 050807: ROTSE-III Optical Limits
  83. GRB 050730, optical observation
  84. GRB050805b: CrAO optical limit
  85. GRB050805a : Null detection report
  86. GRB050730, optical observations
  87. GRB050803, optical observations
  88. Swift-BAT trigger 149118 is very likely not a GRB
  89. Retraction of Swift Trigger 149131 (GRB 050805B)
  90. GRB 050805b: OHP optical limits
  91. GRB 050805b: TAROT optical limits
  92. GRB050805b: MASTER optical observations
  93. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  94. GRB050805a: MASTER optical candidat
  95. Swift-BAT trigger 149118 is probably not a GRB
  96. GRB 050803: RTT150 optical observations
  97. GRB050803: CrAO optical observations, possible OT candidate
  98. GRB 050803: Keck Observations
  99. GRB 050803: Swift-BAT refined analysis
  100. GRB 050802.422: Fading of the afterglow and detection of the host

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