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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').
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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.

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subject:"Swift"
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18694 results found.

  1. GRB040916: Optical observations
  2. An intense burst from SGR1806-20
  3. Very bright burst detected from SGR 1806-20
  4. Increase of SGR 1806-20 activity
  5. Bursting activity from SGR 1806-20 detected with IBAS
  6. Ongoing activity of SGR 1806-20
  7. GRB040706:observation at University of Miyazaki
  8. SGR 1806-20: no IR variability of the proposed counterparts
  9. SGR 1806-20, potential NIR counterpart
  10. Activivty of SGR 1806-20
  11. IBAS GRB Alerts n.1785 to 1791
  12. GRB040422: optical and NIR observations at the VLT
  13. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  14. IBAS GRB Alert 1694
  15. IBAS GRB alerts 1679, 1680, 1681
  16. GRB040223, improved XMM position
  17. IBAS results on a burst from SGR1806-20
  18. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  19. IBAS alert 1180 refers to a burst from SGR 1806-20
  20. Ongoing Bursting Activity from SGR 1806-20 detected with IBAS
  21. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  22. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  23. A burst from SGR 1806-20 detected with IBAS
  24. IPN triangulation of GRB030926 (short/hard; large error box)
  25. IBAS detection of bursts from SGR 1806-20
  26. Radio Observations of SGR1806-20
  27. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  28. Summary of recent IPN and HETE detections of SGR bursts
  29. Clarification of GCN 2354 on SGR1806-20
  30. IPN detection of continued activity from SGR1806-20
  31. 030813 SGR event (Konus-Wind observation)
  32. SGR 1808-20 (=H2802): A Possible new SGR
  33. SGR 1806-20, submm observations
  34. RXTE PCA Observations of SGR1806-20 Region
  35. HETE detection of burst from SGR1806-20
  36. GRB030329 observed as a sudden ionospheric disturbance (SID)
  37. IPN triangulation of GRB021219
  38. IPN detection of continued activity from SGR1806-20
  39. IPN detection of renewed activity from SGR1806-20
  40. IPN detection of continued SGR1900+14 activity
  41. IPN confirmation of the reactivation of SGR1900+14
  42. IPN detection of possible reactivation of SGR1900+14
  43. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  44. SGR1900+14 activity, November 2-4, 2002
  45. Detection of activity from SGR 1900+14 with the RXTE/PCA
  46. IPN detection of a burst from SGR1900+14
  47. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  48. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  49. AXP 1E2259+586: quasi-simultaneous optical observation
  50. AXP 1E2259+586 optical observations
  51. SGR-like Bursts from the AXP 1E 2259+586
  52. IPN detection of possible bursts from SGR1806-20
  53. XRF 020427: Sudden Ionospheric Disturbance (SID)
  54. Mars Odyssey joins the IPN
  55. IPN detection and localization of Cygnus X-1 flares
  56. RXTE Observations of SGR 1900+14
  57. SGR1900+14 activity
  58. IPN/HETE Detection of Bursts from SGR1900+14
  59. IPN detection of further activity from SGR1806-20
  60. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  61. Probable SGR or Short Duration GRB Detected by HETE
  62. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  63. Possible burst from SGR1806-20
  64. IPN detection of SGR1900+14
  65. X-ray precursors to the large flare from SGR 1900+14
  66. SGR 1900+14: No evidence of extended X-ray emission
  67. SGR 1900+14 : RXTE observations
  68. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  69. SGR1900+14
  70. SGR 1900+14: Correction to GCN 1049
  71. Millimeter observation of SGR 1900+14
  72. SGR 1900+14: Detection of extended X-ray emission
  73. Chandra Observations of SGR 1900+14
  74. SGR 1900+14, Chandra observations
  75. Chandra Observations of SGR 1900+14
  76. SGR1900+14, I-band observations
  77. SGR 1806-20 burst activity
  78. BATSE GRB trigger criteria
  79. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  80. GRB990308 not a new SGR
  81. GRB990308, Possible new SGR~0209+70
  82. SGR1900+14, BeppoSAX-GRBM observations
  83. SGR1627-41
  84. SGR1627-41, RXTE/ASM observations
  85. Reduced error box of SGR 1627-41
  86. SGR 1627-41
  87. Discovery of a new SGR source, SGR1627-41
  88. SGR 1900+14
  89. SGR1900+14
  90. SGR1900+14
  91. BATSE on-board GRB trigger change
  92. IRAS 18119-1342 and the possible new SGR
  93. Possible new SGR from US Naval Observatory
  94. RXTE Observations of SGR 1814-13

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