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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').
  1. IPN detection of continued activity from SGR1806-20
  2. 030813 SGR event (Konus-Wind observation)
  3. GRB 030817 = H2808 TAROT optical observations
  4. SGR 1808-20 (=H2802): A Possible new SGR
  5. GRB 021206 Optical Observations
  6. IPN triangulation of GRB030808 (two large error boxes)
  7. IPN triangulation of GRB030806 (large burst; large error box)
  8. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  9. IPN/HETE summary of recent bursts from SGR1806-20
  10. XRF 030723: Detection of a rebrightening in the optical afterglow
  11. GRB030725: Optical observations
  12. XRF030723, BVRcIc field photometry update
  13. IPN triangulation of GRB030801 (large error box)
  14. GRB021206 optical counterpart upper limit
  15. IPN triangulation of GRB030731 (annulus)
  16. IBAS GRB Alerts 1011-1017 NOT CONFIRMED
  17. XRF030723: Re-analysis of ROTSE-III early images
  18. IPN triangulation of GRB030725 (=H2779; small error box)
  19. XRF030723 (=H2777): Second Epoch Magellan Observations
  20. GRB 030725: optical observations.
  21. GRB030725, optical transient observations
  22. IPN triangulation of GRB030726 (large error box)
  23. IPN triangulation of GRB030722 (large error box)
  24. IPN triangulation of GRB030721 (large error box)
  25. XRF030723 Radio Observations
  26. XRF 030723: confirmation of fading optical counterpart
  27. XRF030723(=H2777): Chandra Observations
  28. XRF 030723: VLT spectra
  29. Magellan Observations of XRF030723 (=H2777)
  30. GRB030723: Upper limits from historical observations
  31. GRB030725, possible optical transient
  32. XRF030723: Palomar observations and proposed counterpart
  33. GRB030725 (=H2779): A Bright GRB Localized by HETE
  34. XRF030723: optical observations
  35. XRF030723 (= H2777): Chandra Observations Scheduled
  36. XRF030723, BVRcIc field photometry correction
  37. XRF030723, ROTSE-III Early Observations
  38. XRF030723, BVRcIc field photometry
  39. XRF 030723, optical observations
  40. XRF030723, optical observations
  41. XRF 030723, optical observations
  42. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  43. GRB030723, optical observations
  44. Konus-Wind detection of the bursts from SGR1806-20 region
  45. IBAS GRB Alerts 969 970
  46. SGR 1806-20, submm observations
  47. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  48. IPN triangulation of GRB030717 (annulus)
  49. RXTE PCA Observations of SGR1806-20 Region
  50. GRB030329: Subaru Optical Spectroscopy
  51. Triangulation of GRB030715 (single large error box)
  52. Triangulation of GRB030714 (single large error box)
  53. 030716 NOT a GRB
  54. IPN triangulation of GRB030714 (two large error boxes)
  55. IPN triangulation of GRB030715 (two large error boxes)
  56. GRB030329: RTT150 optical observations
  57. GRBlog: Compilation of all GCN Circ. data
  58. IPN detection of renewed activity from SGR1806-20
  59. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  60. IPN triangulation of GRB030710 (annulus)
  61. IPN triangulation of GRB030709 (annulus)
  62. GRB030706 triangulation (single large error box)
  63. IPN triangulation of GRB030706 (annulus)
  64. IPN triangulation of GRB030629 (annulus)
  65. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  66. 030629 NOT a real GRB
  67. GRB030329, optical observation in May
  68. IPN triangulation of GRB030626 (single large error box)
  69. IPN triangulation of GRB030626 (two large error boxes)
  70. GRB030329: second XMM-Newton observation
  71. GRB030418: R optical observations
  72. HETE detection of burst from SGR1806-20
  73. GRB030329 -- RATAN-600 data in April-May
  74. Final IPN error ellipse for GRB021206 (the polarized GRB)
  75. GRB 021206, Radio afterglow candidate
  76. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  77. IPN triangulation of GRB030607 (annulus)
  78. IPN triangulation of GRB030606 (two alternate error boxes)
  79. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  80. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  81. IPN triangulation of GRB030605B (annulus)
  82. GRB 030528: Optical Observations
  83. IPN triangulation of GRB030605 (annulus)
  84. GRB 030528: tentative NIR counterpart
  85. GRB 030528, radio observations
  86. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  87. GRB030329, further radio observations at GMRT
  88. GRB030528, BVRI field photometry
  89. IPN triangulation of GRB030601 (annulus)
  90. GRB030329, SPM optical observations
  91. GRB030528: Chandra TOO Planned
  92. GRB 030519B: optical observations.
  93. MASTER: optical observation GRB030601
  94. GRB030528(=H2724): Revised SXC Localization
  95. GRB 030329: optical observations
  96. GRB 030329/SN 2003dh: Jitter Episode
  97. GRB 030528, Teramo optical observation
  98. GRB 030528 Bisei optical observation
  99. GRB030528 (H2724): A long GRB localized by HETE
  100. GRB 030329: Correction to GCN 2254

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