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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"

11075 results found.

  1. IPN triangulation of GRB040228 (H3066, H3067)
  2. GRB 040223: further offline analysis
  3. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  4. GRB040106, likely optical afterglow
  5. GRB031220: observation at Univercity of Miyazaki
  6. GRB 040106 : peak flux
  7. IPN triangulation of an intermediate burst from SGR1806-20
  8. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  9. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  10. GRB031220: Palomar Observations
  11. GRB 031220: Subaru observation
  12. GRB 031220: Optical observation at Tokyo Tech
  13. GRB031220: ROTSE-IIIb Optical Limits
  14. GRB031220 : Optical Observation of Lulin Observatory
  15. GRB 2974 follow-up observations
  16. GRB 021203: A Normal GRB viewed far off axis?
  17. GRB 031203: Variable Radio Source
  18. GRB 031203: Optical/IR Astrometry
  19. GRB 031203: Deep NIR NTT & VLT observations
  20. GRB 031203: Radio detection
  21. IPN triangulation of GRB031127A and B (quasi-simultaneous; large error boxes)
  22. GRB 031203: further analysis of INTEGRAL data
  23. GRB 031203: A long GRB detected with INTEGRAL
  24. IPN/HETE localization of GRB031109 (=H2917; large error box)
  25. IPN detection of activity from SGR1806-20
  26. IPN triangulation of GRB031107 (two large error boxes)
  27. HETE Prompt GRB Spectral Analyses
  28. XRF031109 (=H2919): A very long XRF localized by HETE
  29. Lulin optical follow-up observations of GRB031026
  30. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  31. IBAS alert 1180 refers to a burst from SGR 1806-20
  32. Ongoing Bursting Activity from SGR 1806-20 detected with IBAS
  33. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  34. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  35. IPN detection of continued activity from SGR1806-20
  36. A burst from SGR 1806-20 detected with IBAS
  37. IPN triangulation of GRB030922B (large error box)
  38. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  39. IPN triangulation of GRB030921 (large error box)
  40. IPN triangulation of GRB030919 (large error box)
  41. GRB 030913, optical candidate
  42. GRB030913: AAVSO optical observations
  43. GRB030913 (=H2849): TAROT Observations
  44. XRF030824: Optical observations
  45. IPN triangulation of GRB030903 (large error box)
  46. IBAS detection of bursts from SGR 1806-20
  47. Radio Observations of SGR1806-20
  48. IPN triangulation of GRB030831 (annulus)
  49. IPN triangulation of GRB030830 (large error box)
  50. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  51. Summary of recent IPN and HETE detections of SGR bursts
  52. Clarification of GCN 2354 on SGR1806-20
  53. IPN detection of continued activity from SGR1806-20
  54. 030813 SGR event (Konus-Wind observation)
  55. SGR 1808-20 (=H2802): A Possible new SGR
  56. IPN triangulation of GRB030806 (large burst; large error box)
  57. IPN/HETE summary of recent bursts from SGR1806-20
  58. GRB030725, optical transient observations
  59. GRB030723: Upper limits from historical observations
  60. GRB030725, possible optical transient
  61. XRF030723, BVRcIc field photometry correction
  62. XRF030723, ROTSE-III Early Observations
  63. Konus-Wind detection of the bursts from SGR1806-20 region
  64. SGR 1806-20, submm observations
  65. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  66. IPN triangulation of GRB030717 (annulus)
  67. RXTE PCA Observations of SGR1806-20 Region
  68. Triangulation of GRB030715 (single large error box)
  69. IPN triangulation of GRB030714 (two large error boxes)
  70. IPN triangulation of GRB030715 (two large error boxes)
  71. IPN detection of renewed activity from SGR1806-20
  72. IPN triangulation of GRB030629 (annulus)
  73. GRB030329: second XMM-Newton observation
  74. GRB030418: R optical observations
  75. HETE detection of burst from SGR1806-20
  76. GRB030329 -- RATAN-600 data in April-May
  77. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  78. IPN triangulation of GRB030606 (two alternate error boxes)
  79. GRB 030528: tentative NIR counterpart
  80. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  81. IPN triangulation of GRB030601 (annulus)
  82. GRB030329, SPM optical observations
  83. GRB 030329: optical observations
  84. GRB 030329/SN 2003dh: Jitter Episode
  85. GRB 030329: optical photometry at various french observatories
  86. GRB030329, Optical observations
  87. GRB 030329/SN 2003dh: Possible increase in brightness
  88. GRB030329: XMM-Newton observation
  89. GRB030429, refiend optical brightness
  90. GRB 030329: Optical limit (contemporaneous photography)
  91. GRB030501C triangulation (annulus)
  92. GRB 030329 Optical Observations
  93. GRB 030329, BVRI photometry
  94. GRB030429: Optical Observations
  95. GRB 030501: TAROT possible candidate counterpart
  96. GRB030429, possible optical counterpart
  97. GRB 030429: ROTSE-III observations
  98. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  99. GRB 030329, the review of the sky area in plate archive (1950-1998)
  100. GRB030329, optical observation

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