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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"

5050 results found.

  1. GRB 050915: ROTSE-III optical limits
  2. GRB 050915: Swift detection of a GRB
  3. GRB050908 : Swift-XRT refined analysis
  4. GRB 050908: KAIT observations
  5. GRB 050906: Swift/BAT Detection of a possible burst
  6. GRB 050824: MDM Observations
  7. GRB 050826: Swift XRT preliminary analysis results
  8. GRB050824: First 2 hours of power low optical decay?
  9. GRB 050824: ROTSE-III Optical Limits
  10. GRB050820A: RTT150 optical observations
  11. GRB 050822: Swift-BAT refined analysis
  12. GRB050820: refined XRT analysis
  13. GRB050819: refined XRT analysis
  14. GRB050819: Swift XRT position
  15. GRB 050803: early Swift XRT analysis results
  16. GRB 050802: early Swift XRT analysis results
  17. GRB 050730: XRT refined analysis
  18. GRB 050724: Chandra Observations of the X-ray Afterglow
  19. GRB050724: Refined Radio Position
  20. GRB050724: VLT observations of the variable source
  21. GRB 050726: early Swift XRT analysis results
  22. GRB 050724: J-band observations
  23. GRB050724: Radio Observation
  24. GRB 050724: spectroscopy of object in the XRT error circle
  25. GRB 050724: Optical limit
  26. GRB 050724: optical and near-IR observations
  27. GRB 050724: Optical imaging/astrometry
  28. GRB 050724: RTT150 optical observations
  29. GRB 050724: early Swift XRT analysis results
  30. GRB 050724: possible host galaxy in DSS
  31. GRB 050714, optical observations
  32. GRB 050713b : Lulin R-band observations
  33. GRB 050701: Refined XRT analysis
  34. GRB 050701: Swift XRT afterglow position
  35. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  36. XRF 050509c: Optical monitoring
  37. GRB 050525a, Mid-Infrared Observations
  38. GRB 050607: Optical decay and spectral slope
  39. GRB050607,optical observation
  40. GRB050525: Optical observations
  41. XRF050522: NIR observations of XRT candidate
  42. XRF 050522: Swift XRT refined analysis
  43. GRB050522,optical observation
  44. RBO Observations of GRB050522
  45. XRF 050522: Swift XRT observation
  46. RBO Observations of GRB050520
  47. GRB 050509a: Swift-BAT refined analysis
  48. Swift Detection of GRB050509b: A short duration burst
  49. GRB 050504: Swift XRT position
  50. GRB (?) 050504: IR Observations, Intriguing Source
  51. GRB 050502a: RBO Observations
  52. GRB050502B Swift-BAT refined analysis
  53. GRB 050416: Swift XRT Position
  54. GRB 050412: Swift-BAT refined analysis
  55. GRB 050401: Optical limit
  56. GRB 050408: Optical limit
  57. GRB 050408: Swift XRT measurement of possible jet break
  58. GRB050319: radio observation
  59. Konus-Wind observation of GRB 050326
  60. GRB 050319: Optical observation
  61. GRB050223: analysis of the XMM-Newton observation
  62. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  63. GRB050309: CONCAM pre-trigger and trigger coincident optical
  64. GRB 050219b: CORRECTION: Swift XRT Position
  65. GRB 050219b: Swift XRT Position
  66. GRB050209: REM optical observations
  67. GRB050124: No Swift UVOT Detection of Afterglow Emission
  68. GRB050124,optical observation
  69. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  70. GRB050123: P60 Observations
  71. Fourth Epoch VLA observations of SGR 1806-20
  72. GRB041219; RXTE ASM Observations
  73. GRB041223: decay of the afterglow
  74. GRB041223: optical and NIR observations with REM
  75. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  76. GRB 041219: Radio Afterglow Detection
  77. GRB 041218 : Radio Observations
  78. GRB 041217: LCO40 Optical Observations and Possible Candidates
  79. GRB 041211: KAIT observations
  80. GRB970815: Discovery of Optical Afterglow
  81. GRB 040924: Afterglow Color
  82. GRB 041016: Optical limits
  83. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  84. GRB040924,optical observation
  85. GRB040924,optical observation
  86. GRB040924, RTT150 optical observation
  87. GRB 040924: Subaru NIR observation
  88. GRB 040924, optical follow-up
  89. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  90. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  91. IBAS GRB Alerts 1978-1980
  92. GRB040903 - A XRF?
  93. GRB040825A: optical limit before GRB
  94. GCN GRB OBSERBATION REPORT
  95. GRB040825B: Correction to GCN 2657
  96. XRF 040812: optical observation at VLT
  97. XRF040701: Second-Epoch Chandra Observations
  98. XRF040701: First-Epoch Chandra Observations
  99. GRB040624, optical observations
  100. MASTER: GRB 040624 optical observation after 0,48d

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