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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"

36028 results found.

  1. GRB 030913, optical candidate
  2. GRB 030913, BOOTES observations
  3. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  4. GRB030913 (=H2849): TAROT Observations
  5. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  6. Magellan Observations of GRB030725 (=H2779)
  7. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  8. IPN triangulation of GRB030908 (annulus)
  9. GRB 030913: Optical limit at RIKEN
  10. XRF030824: Optical observations
  11. IPN triangulation of GRB030903 (large error box)
  12. IPN triangulation of GRB030831 (annulus)
  13. IPN triangulation of GRB030830 (large error box)
  14. GRB 030824: Candidate Follow-Up
  15. IPN triangulation of GRB030827 (large error box)
  16. GRB 030823 observation at Ouda
  17. XRF030824: Second-epoch Palomar observations
  18. IPN triangulation of GRB030822 (annulus)
  19. GRB030823: Palomar observations
  20. XRF030824: Palomar observations
  21. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  22. IPN triangulation of GRB030821 (=H2814; refined error box)
  23. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  24. Summary of recent IPN and HETE detections of SGR bursts
  25. IPN triangulation of GRB030814 (annulus)
  26. IPN detection of continued activity from SGR1806-20
  27. 030813 SGR event (Konus-Wind observation)
  28. GRB 030817 = H2808 TAROT optical observations
  29. SGR 1808-20 (=H2802): A Possible new SGR
  30. GRB 021206 Optical Observations
  31. IPN triangulation of GRB030808 (two large error boxes)
  32. IPN triangulation of GRB030806 (large burst; large error box)
  33. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  34. IPN/HETE summary of recent bursts from SGR1806-20
  35. XRF 030723: Detection of a rebrightening in the optical afterglow
  36. GRB030725: Optical observations
  37. XRF030723, BVRcIc field photometry update
  38. IPN triangulation of GRB030801 (large error box)
  39. GRB021206 optical counterpart upper limit
  40. IPN triangulation of GRB030731 (annulus)
  41. IBAS GRB Alerts 1011-1017 NOT CONFIRMED
  42. IPN triangulation of GRB030725 (=H2779; small error box)
  43. XRF030723 (=H2777): Second Epoch Magellan Observations
  44. GRB 030725: optical observations.
  45. GRB030725, optical transient observations
  46. IPN triangulation of GRB030726 (large error box)
  47. IPN triangulation of GRB030722 (large error box)
  48. IPN triangulation of GRB030721 (large error box)
  49. XRF030723 Radio Observations
  50. XRF030723(=H2777): Chandra Observations
  51. Magellan Observations of XRF030723 (=H2777)
  52. GRB030723: Upper limits from historical observations
  53. GRB030725, possible optical transient
  54. XRF030723: Palomar observations and proposed counterpart
  55. GRB030725 (=H2779): A Bright GRB Localized by HETE
  56. XRF030723: optical observations
  57. XRF030723 (= H2777): Chandra Observations Scheduled
  58. XRF030723, BVRcIc field photometry
  59. XRF030723, optical observations
  60. GRB030723, optical observations
  61. IBAS GRB Alerts 969 970
  62. IPN triangulation of GRB030717 (annulus)
  63. GRB030329: Subaru Optical Spectroscopy
  64. Triangulation of GRB030715 (single large error box)
  65. Triangulation of GRB030714 (single large error box)
  66. 030716 NOT a GRB
  67. IPN triangulation of GRB030714 (two large error boxes)
  68. IPN triangulation of GRB030715 (two large error boxes)
  69. GRB030329: RTT150 optical observations
  70. GRBlog: Compilation of all GCN Circ. data
  71. IPN detection of renewed activity from SGR1806-20
  72. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  73. IPN triangulation of GRB030710 (annulus)
  74. IPN triangulation of GRB030709 (annulus)
  75. GRB030706 triangulation (single large error box)
  76. IPN triangulation of GRB030706 (annulus)
  77. IPN triangulation of GRB030629 (annulus)
  78. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  79. 030629 NOT a real GRB
  80. IPN triangulation of GRB030626 (single large error box)
  81. IPN triangulation of GRB030626 (two large error boxes)
  82. GRB030418: R optical observations
  83. GRB030329 -- RATAN-600 data in April-May
  84. Final IPN error ellipse for GRB021206 (the polarized GRB)
  85. GRB 021206, Radio afterglow candidate
  86. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  87. IPN triangulation of GRB030607 (annulus)
  88. IPN triangulation of GRB030606 (two alternate error boxes)
  89. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  90. IPN triangulation of GRB030605B (annulus)
  91. GRB 030528: Optical Observations
  92. IPN triangulation of GRB030605 (annulus)
  93. GRB 030528: tentative NIR counterpart
  94. GRB 030528, radio observations
  95. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  96. GRB030329, further radio observations at GMRT
  97. GRB030528, BVRI field photometry
  98. IPN triangulation of GRB030601 (annulus)
  99. GRB030528: Chandra TOO Planned
  100. GRB 030519B: optical observations.

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