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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"

35952 results found.

  1. IBAS alert 1180 refers to a burst from SGR 1806-20
  2. HETE Prompt GRB Light Curves and Color-Color Diagrams
  3. IPN triangulation of GRB031014 (annulus)
  4. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  5. IPN triangulation of GRB031008 (annulus)
  6. IPN detection of continued activity from SGR1806-20
  7. IPN triangulation of GRB031007 (two large error boxes)
  8. XRF 030723: Subaru Optical Observations
  9. IPN triangulation of GRB031004B (annulus)
  10. IPN triangulation of GRB031004A (short/hard; annulus)
  11. IPN triangulation of GRB030929 (short/hard; annulus)
  12. XRF 030824: Early follow-up observation at Kiso observatory
  13. XRF 030824: observations at CFHT
  14. IPN triangulation of GRB030926 (short/hard; large error box)
  15. IPN triangulation of GRB030922B (large error box)
  16. IPN triangulation of GRB030922A (large error box)
  17. IPN triangulation of GRB030921 (large error box)
  18. IPN triangulation of GRB030919 (large error box)
  19. GRB030922 triangulation (annulus)
  20. GRB030913: Subaru Optical Observations
  21. GRB 030913: ROTSE-3c Optical Observations
  22. GRB030913: OT's limit by MASTER
  23. GRB030921 triangulation (annulus)
  24. GRB030913, candidate afterglow observations
  25. GRB 030913, optical candidate
  26. GRB 030913, BOOTES observations
  27. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  28. GRB030913 (=H2849): TAROT Observations
  29. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  30. Magellan Observations of GRB030725 (=H2779)
  31. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  32. IPN triangulation of GRB030908 (annulus)
  33. GRB 030913: Optical limit at RIKEN
  34. XRF030824: Optical observations
  35. IPN triangulation of GRB030903 (large error box)
  36. IPN triangulation of GRB030831 (annulus)
  37. IPN triangulation of GRB030830 (large error box)
  38. GRB 030824: Candidate Follow-Up
  39. IPN triangulation of GRB030827 (large error box)
  40. GRB 030823 observation at Ouda
  41. XRF030824: Second-epoch Palomar observations
  42. IPN triangulation of GRB030822 (annulus)
  43. GRB030823: Palomar observations
  44. XRF030824: Palomar observations
  45. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  46. IPN triangulation of GRB030821 (=H2814; refined error box)
  47. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  48. Summary of recent IPN and HETE detections of SGR bursts
  49. IPN triangulation of GRB030814 (annulus)
  50. IPN detection of continued activity from SGR1806-20
  51. 030813 SGR event (Konus-Wind observation)
  52. GRB 030817 = H2808 TAROT optical observations
  53. SGR 1808-20 (=H2802): A Possible new SGR
  54. GRB 021206 Optical Observations
  55. IPN triangulation of GRB030808 (two large error boxes)
  56. IPN triangulation of GRB030806 (large burst; large error box)
  57. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  58. IPN/HETE summary of recent bursts from SGR1806-20
  59. XRF 030723: Detection of a rebrightening in the optical afterglow
  60. GRB030725: Optical observations
  61. XRF030723, BVRcIc field photometry update
  62. IPN triangulation of GRB030801 (large error box)
  63. GRB021206 optical counterpart upper limit
  64. IPN triangulation of GRB030731 (annulus)
  65. IBAS GRB Alerts 1011-1017 NOT CONFIRMED
  66. IPN triangulation of GRB030725 (=H2779; small error box)
  67. XRF030723 (=H2777): Second Epoch Magellan Observations
  68. GRB 030725: optical observations.
  69. GRB030725, optical transient observations
  70. IPN triangulation of GRB030726 (large error box)
  71. IPN triangulation of GRB030722 (large error box)
  72. IPN triangulation of GRB030721 (large error box)
  73. XRF030723 Radio Observations
  74. XRF030723(=H2777): Chandra Observations
  75. Magellan Observations of XRF030723 (=H2777)
  76. GRB030723: Upper limits from historical observations
  77. GRB030725, possible optical transient
  78. XRF030723: Palomar observations and proposed counterpart
  79. GRB030725 (=H2779): A Bright GRB Localized by HETE
  80. XRF030723: optical observations
  81. XRF030723 (= H2777): Chandra Observations Scheduled
  82. XRF030723, BVRcIc field photometry
  83. XRF030723, optical observations
  84. GRB030723, optical observations
  85. IBAS GRB Alerts 969 970
  86. IPN triangulation of GRB030717 (annulus)
  87. GRB030329: Subaru Optical Spectroscopy
  88. Triangulation of GRB030715 (single large error box)
  89. Triangulation of GRB030714 (single large error box)
  90. 030716 NOT a GRB
  91. IPN triangulation of GRB030714 (two large error boxes)
  92. IPN triangulation of GRB030715 (two large error boxes)
  93. GRB030329: RTT150 optical observations
  94. GRBlog: Compilation of all GCN Circ. data
  95. IPN detection of renewed activity from SGR1806-20
  96. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  97. IPN triangulation of GRB030710 (annulus)
  98. IPN triangulation of GRB030709 (annulus)
  99. GRB030706 triangulation (single large error box)
  100. IPN triangulation of GRB030706 (annulus)

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