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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"

613 results found.

  1. SGR 1806-20: Temporal and Spectral behavior of radio transient
  2. ATCA observations of SGR 1806-20
  3. SGR 1806-20, RHESSI observations of the 041227 giant flare
  4. Third epoch observations of SGR 1806-20 with VLA
  5. Second Epoch VLA observations of SGR 1806-20
  6. Second-epoch VLA observations of SGR 1806-20
  7. SGR1806: Detection of a Sudden Ionospheric Disturbance
  8. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  9. VLA observations of SGR 1806-20
  10. SGR1806 VLA Observations
  11. VLA observations of SGR 1806-20
  12. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  13. Detection of the SGR 1806-20 giant outburst back-scattered by the
  14. The giant outburst from SGR 1806-20
  15. Giant flare from SGR 1806-20 detected by INTEGRAL
  16. Very high activity of SGR 1806-20
  17. Summary of the recent bursts from SGR 1806-20
  18. IBAS GRB Alert # 2034
  19. Bright bursts from SGR1806-20
  20. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  21. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  22. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  23. SGR 1806-20 still active
  24. An intense burst from SGR1806-20
  25. Very bright burst detected from SGR 1806-20
  26. Increase of SGR 1806-20 activity
  27. Bursting activity from SGR 1806-20 detected with IBAS
  28. Ongoing activity of SGR 1806-20
  29. GRB040706:observation at University of Miyazaki
  30. SGR 1806-20: no IR variability of the proposed counterparts
  31. SGR 1806-20, potential NIR counterpart
  32. Activivty of SGR 1806-20
  33. IBAS GRB Alerts n.1785 to 1791
  34. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  35. IBAS GRB Alert 1694
  36. IBAS GRB alerts 1679, 1680, 1681
  37. IBAS results on a burst from SGR1806-20
  38. IBAS alert 1180 refers to a burst from SGR 1806-20
  39. Ongoing Bursting Activity from SGR 1806-20 detected with IBAS
  40. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  41. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  42. A burst from SGR 1806-20 detected with IBAS
  43. IPN triangulation of GRB030926 (short/hard; large error box)
  44. IBAS detection of bursts from SGR 1806-20
  45. Radio Observations of SGR1806-20
  46. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  47. Summary of recent IPN and HETE detections of SGR bursts
  48. Clarification of GCN 2354 on SGR1806-20
  49. IPN detection of continued activity from SGR1806-20
  50. 030813 SGR event (Konus-Wind observation)
  51. SGR 1808-20 (=H2802): A Possible new SGR
  52. SGR 1806-20, submm observations
  53. RXTE PCA Observations of SGR1806-20 Region
  54. HETE detection of burst from SGR1806-20
  55. GRB030329 observed as a sudden ionospheric disturbance (SID)
  56. IPN triangulation of GRB021219
  57. IPN detection of continued activity from SGR1806-20
  58. IPN detection of renewed activity from SGR1806-20
  59. IPN detection of continued SGR1900+14 activity
  60. IPN confirmation of the reactivation of SGR1900+14
  61. IPN detection of possible reactivation of SGR1900+14
  62. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  63. SGR1900+14 activity, November 2-4, 2002
  64. Detection of activity from SGR 1900+14 with the RXTE/PCA
  65. IPN detection of a burst from SGR1900+14
  66. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  67. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  68. AXP 1E2259+586: quasi-simultaneous optical observation
  69. AXP 1E2259+586 optical observations
  70. SGR-like Bursts from the AXP 1E 2259+586
  71. IPN detection of possible bursts from SGR1806-20
  72. XRF 020427: Sudden Ionospheric Disturbance (SID)
  73. Mars Odyssey joins the IPN
  74. IPN detection and localization of Cygnus X-1 flares
  75. RXTE Observations of SGR 1900+14
  76. SGR1900+14 activity
  77. IPN/HETE Detection of Bursts from SGR1900+14
  78. IPN detection of further activity from SGR1806-20
  79. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  80. Probable SGR or Short Duration GRB Detected by HETE
  81. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  82. Possible burst from SGR1806-20
  83. IPN detection of SGR1900+14
  84. X-ray precursors to the large flare from SGR 1900+14
  85. SGR 1900+14: No evidence of extended X-ray emission
  86. SGR 1900+14 : RXTE observations
  87. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  88. SGR1900+14
  89. SGR 1900+14: Correction to GCN 1049
  90. Millimeter observation of SGR 1900+14
  91. SGR 1900+14: Detection of extended X-ray emission
  92. Chandra Observations of SGR 1900+14
  93. SGR 1900+14, Chandra observations
  94. Chandra Observations of SGR 1900+14
  95. SGR1900+14, I-band observations
  96. SGR 1806-20 burst activity
  97. BATSE GRB trigger criteria
  98. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  99. GRB990308 not a new SGR
  100. GRB990308, Possible new SGR~0209+70

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