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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"

4942 results found.

  1. GRB050525: Optical observations
  2. XRF 050522: Swift XRT refined analysis
  3. RBO Observations of GRB050520
  4. GRB 050505: SARA Observations
  5. GRB 050502a: Swift XRT Upper Limit
  6. GRB 050416: Swift/UVOT detection of afterglow emission
  7. GRB050416: Refined Swift-XRT analysis
  8. GRB 050416: Swift XRT Position
  9. GRB050416: P60 Afterglow Candidate
  10. GRB 050412: Subaru observations
  11. GRB 050412: optical limit
  12. GRB 050412: Swift-BAT refined analysis
  13. GRB 050412: Swift XRT Position
  14. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  15. GRB 050408, SMARTS optical/IR afterglow observations
  16. GRB 050408: Swift XRT Position
  17. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  18. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  19. GRB050331: No Afterglow Detected
  20. Swift-BAT detection of a bright outburst from SGR1806-20
  21. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  22. GRB 050318: Swift/UVOT detection of afterglow emission
  23. GRB 050318: Magellan optical afterglow identification
  24. GRB050318: Swift XRT position
  25. GRB050223: analysis of the XMM-Newton observation
  26. GRB050316: MASTER before, simultanious and follow up optical
  27. GRB 050306: ROTSE-III early limits
  28. GRB 050315, SMARTS optical/IR afterglow observations
  29. GRB050309: CONCAM pre-trigger and trigger coincident optical
  30. GRB 050306: Confirmation of X-ray afterglow
  31. GRB 050306: further TAROT optical data
  32. GRB 050306: TAROT optical observations
  33. GRB 050306,optical observation
  34. GRB 050306: Swift-BAT detection of a long burst
  35. GRB050215B: Late-Time Swift UVOT Observations
  36. PROMPT VRcIc Observations of GRB 050223
  37. GRB050223: No Swift UVOT Detection of Afterglow Emission
  38. GRB050223: ROTSE-III Optical Observations
  39. GRB 050223 Swift/BAT detection of a burst
  40. GRB 050223: Swift XRT Position
  41. GRB 050215b: Swift XRT Observations
  42. GRB 050209 Optical observations
  43. GRB 050209: Optical observation
  44. GRB 050202: Short burst detected by Swift-BAT
  45. GRB 050129: a weak long GRB detected with INTEGRAL
  46. GRB050126: Burst Parameters Measured by BAT
  47. GRB 050126: Prompt XRT detection and localization
  48. GRB050124,optical observation
  49. GRB050124: Updated Swift XRT Position and Fluxes
  50. GRB050124: Swift-BAT position of a double-peaked burst
  51. GRB050117: Palomar WIRC Ks-band observations
  52. GRB050117b: Swift-BAT detection of a weak burst
  53. Second Epoch VLA observations of SGR 1806-20
  54. GRB041223: optical and NIR observations with REM
  55. GRB041219: Confirmed NIR Afterglow
  56. GRB 041218: Optical Observation
  57. GRB 041211: Infrared Observations
  58. GRB 041211: KAIT observations
  59. SGR 1806-20 still active
  60. GRB040929,optical observation
  61. XRF 040912, identification of CXO sources
  62. GRB040916 (= H3558): A Long XRF Localized by HETE
  63. IBAS GRB Alerts 1978-1980
  64. GRB040903 - A XRF?
  65. GRB040903, REM near-IR observation
  66. Possible GRB 040903 - further analysis
  67. Bursting activity from SGR 1806-20 detected with IBAS
  68. GRB 040730: a long GRB detected with INTEGRAL
  69. GRB040709 J,H-band observations
  70. IPN Summary of SGR1806-20 Activity in 2004
  71. GRB 040606: Optical observations
  72. Activivty of SGR 1806-20
  73. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  74. GRB 040403: Optical Observations
  75. GRB 040403 Optical Observations
  76. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  77. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  78. GRB031220: observation at Univercity of Miyazaki
  79. GRB 031220: Optical observation at Tokyo Tech
  80. IPN triangulation of GRB031214 (short/hard; very intense; small error box)
  81. GRB 2974 follow-up observations
  82. GRB 031203: Discovery of a dust echo
  83. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  84. GRB031203: Optical Observations
  85. GRB031203: Planned XMM-Newton observation
  86. Lulin optical follow-up observations of GRB031026
  87. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  88. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  89. IBAS detection of bursts from SGR 1806-20
  90. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  91. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  92. GRB030329: RTT150 optical observations
  93. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  94. GRB030418: R optical observations
  95. GRB030528 (H2724): A long GRB localized by HETE
  96. GRB030329, Optical observations
  97. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  98. GRB030429: RTT150 optical observations, a possible host galaxy
  99. GRB030329: RTT150 optical observations and upper limit for a host
  100. GRB030329: RTT150 optical observations and upper limit for a host

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