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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"

42583 results found.

  1. IPN triangulation of GRB030830 (large error box)
  2. GRB 030824: Candidate Follow-Up
  3. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  4. IPN triangulation of GRB030827 (large error box)
  5. GRB 030823 observation at Ouda
  6. XRF030824: Second-epoch Palomar observations
  7. IPN triangulation of GRB030822 (annulus)
  8. GRB030823: optical observations
  9. GRB030823: Palomar observations
  10. XRF030824: Palomar observations
  11. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  12. GRB030823: optical observation at Tokyo Tech
  13. RAPTOR observations of GRB030823
  14. IPN triangulation of GRB030821 (=H2814; refined error box)
  15. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  16. Summary of recent IPN and HETE detections of SGR bursts
  17. IPN triangulation of GRB030814 (annulus)
  18. IPN detection of continued activity from SGR1806-20
  19. 030813 SGR event (Konus-Wind observation)
  20. GRB 030817 = H2808 TAROT optical observations
  21. SGR 1808-20 (=H2802): A Possible new SGR
  22. GRB 021206 Optical Observations
  23. IPN triangulation of GRB030808 (two large error boxes)
  24. IPN triangulation of GRB030806 (large burst; large error box)
  25. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  26. IPN/HETE summary of recent bursts from SGR1806-20
  27. XRF 030723: Detection of a rebrightening in the optical afterglow
  28. GRB030725: Optical observations
  29. XRF030723, BVRcIc field photometry update
  30. IPN triangulation of GRB030801 (large error box)
  31. GRB021206 optical counterpart upper limit
  32. IPN triangulation of GRB030731 (annulus)
  33. IBAS GRB Alerts 1011-1017 NOT CONFIRMED
  34. XRF030723: Re-analysis of ROTSE-III early images
  35. IPN triangulation of GRB030725 (=H2779; small error box)
  36. XRF030723 (=H2777): Second Epoch Magellan Observations
  37. GRB 030725: optical observations.
  38. GRB030725, optical transient observations
  39. IPN triangulation of GRB030726 (large error box)
  40. IPN triangulation of GRB030722 (large error box)
  41. IPN triangulation of GRB030721 (large error box)
  42. XRF030723 Radio Observations
  43. XRF 030723: confirmation of fading optical counterpart
  44. XRF030723(=H2777): Chandra Observations
  45. XRF 030723: VLT spectra
  46. Magellan Observations of XRF030723 (=H2777)
  47. GRB030723: Upper limits from historical observations
  48. GRB030725, possible optical transient
  49. XRF030723: Palomar observations and proposed counterpart
  50. GRB030725 (=H2779): A Bright GRB Localized by HETE
  51. XRF030723 (= H2777): Chandra Observations Scheduled
  52. XRF030723, BVRcIc field photometry correction
  53. XRF030723, ROTSE-III Early Observations
  54. XRF030723, BVRcIc field photometry
  55. XRF030723, optical observations
  56. XRF 030723, optical observations
  57. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  58. GRB030723, optical observations
  59. Konus-Wind detection of the bursts from SGR1806-20 region
  60. IBAS GRB Alerts 969 970
  61. SGR 1806-20, submm observations
  62. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  63. IPN triangulation of GRB030717 (annulus)
  64. RXTE PCA Observations of SGR1806-20 Region
  65. GRB030329: Subaru Optical Spectroscopy
  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. GRB030329, optical observation in May
  81. IPN triangulation of GRB030626 (single large error box)
  82. IPN triangulation of GRB030626 (two large error boxes)
  83. GRB030329: second XMM-Newton observation
  84. GRB030418: R optical observations
  85. HETE detection of burst from SGR1806-20
  86. Final IPN error ellipse for GRB021206 (the polarized GRB)
  87. GRB 021206, Radio afterglow candidate
  88. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  89. IPN triangulation of GRB030607 (annulus)
  90. IPN triangulation of GRB030606 (two alternate error boxes)
  91. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  92. IPN triangulation of GRB030605B (annulus)
  93. GRB 030528: Optical Observations
  94. IPN triangulation of GRB030605 (annulus)
  95. GRB 030528: tentative NIR counterpart
  96. GRB 030528, radio observations
  97. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  98. GRB030329, further radio observations at GMRT
  99. GRB030528, BVRI field photometry
  100. IPN triangulation of GRB030601 (annulus)

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