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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"

5033 results found.

  1. GRB 050412: Subaru observations
  2. GRB 050412: optical limit
  3. GRB 050412: Swift-BAT refined analysis
  4. GRB 050412: Swift XRT Position
  5. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  6. GRB 050408, SMARTS optical/IR afterglow observations
  7. GRB 050408: Swift XRT Position
  8. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  9. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  10. GRB050331: No Afterglow Detected
  11. Swift-BAT detection of a bright outburst from SGR1806-20
  12. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  13. GRB 050318: Swift/UVOT detection of afterglow emission
  14. GRB 050318: Magellan optical afterglow identification
  15. GRB050318: Swift XRT position
  16. GRB050223: analysis of the XMM-Newton observation
  17. GRB050316: MASTER before, simultanious and follow up optical
  18. GRB 050306: ROTSE-III early limits
  19. GRB 050315, SMARTS optical/IR afterglow observations
  20. GRB050309: CONCAM pre-trigger and trigger coincident optical
  21. GRB 050306: Confirmation of X-ray afterglow
  22. GRB 050306: further TAROT optical data
  23. GRB 050306: TAROT optical observations
  24. GRB 050306,optical observation
  25. GRB 050306: Swift-BAT detection of a long burst
  26. GRB050215B: Late-Time Swift UVOT Observations
  27. PROMPT VRcIc Observations of GRB 050223
  28. GRB050223: No Swift UVOT Detection of Afterglow Emission
  29. GRB050223: ROTSE-III Optical Observations
  30. GRB 050223 Swift/BAT detection of a burst
  31. GRB 050223: Swift XRT Position
  32. GRB 050215b: Swift XRT Observations
  33. GRB 050209 Optical observations
  34. GRB 050209: Optical observation
  35. GRB 050202: Short burst detected by Swift-BAT
  36. GRB 050129: a weak long GRB detected with INTEGRAL
  37. GRB050126: Burst Parameters Measured by BAT
  38. GRB 050126: Prompt XRT detection and localization
  39. GRB050124,optical observation
  40. GRB050124: Updated Swift XRT Position and Fluxes
  41. GRB050124: Swift-BAT position of a double-peaked burst
  42. GRB050117: Palomar WIRC Ks-band observations
  43. GRB050117b: Swift-BAT detection of a weak burst
  44. Second Epoch VLA observations of SGR 1806-20
  45. GRB041223: optical and NIR observations with REM
  46. GRB041219: Confirmed NIR Afterglow
  47. GRB 041218: Optical Observation
  48. GRB 041211: Infrared Observations
  49. GRB 041211: KAIT observations
  50. SGR 1806-20 still active
  51. GRB040929,optical observation
  52. XRF 040912, identification of CXO sources
  53. GRB040916 (= H3558): A Long XRF Localized by HETE
  54. IBAS GRB Alerts 1978-1980
  55. GRB040903 - A XRF?
  56. GRB040903, REM near-IR observation
  57. Possible GRB 040903 - further analysis
  58. Bursting activity from SGR 1806-20 detected with IBAS
  59. GRB 040730: a long GRB detected with INTEGRAL
  60. GRB040709 J,H-band observations
  61. IPN Summary of SGR1806-20 Activity in 2004
  62. GRB 040606: Optical observations
  63. Activivty of SGR 1806-20
  64. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  65. GRB 040403: Optical Observations
  66. GRB 040403 Optical Observations
  67. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  68. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  69. GRB031220: observation at Univercity of Miyazaki
  70. GRB 031220: Optical observation at Tokyo Tech
  71. IPN triangulation of GRB031214 (short/hard; very intense; small error box)
  72. GRB 2974 follow-up observations
  73. GRB 031203: Discovery of a dust echo
  74. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  75. GRB031203: Optical Observations
  76. GRB031203: Planned XMM-Newton observation
  77. Lulin optical follow-up observations of GRB031026
  78. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  79. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  80. IBAS detection of bursts from SGR 1806-20
  81. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  82. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  83. GRB030329: RTT150 optical observations
  84. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  85. GRB030418: R optical observations
  86. GRB030528 (H2724): A long GRB localized by HETE
  87. GRB030329, Optical observations
  88. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  89. GRB030429: RTT150 optical observations, a possible host galaxy
  90. GRB030329: RTT150 optical observations and upper limit for a host
  91. GRB030329: RTT150 optical observations and upper limit for a host
  92. GRB030501 localized by INTEGRAL
  93. GRB030329: optical polarization
  94. GRB030329: 444 AAVSO Measurements
  95. GRB 030329: SARA Optical Observations
  96. IPN triangulation of GRB030414 (small error box)
  97. GRB 030329: possible color change
  98. GRB030329: Kiso B and R band observations
  99. GRB030329: More AAVSO VR obs
  100. GRB030328: R upper limit after 6 hours by MASTER

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