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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"

37797 results found.

  1. IPN triangulation of GRB030806 (large burst; large error box)
  2. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  3. IPN/HETE summary of recent bursts from SGR1806-20
  4. XRF 030723: Detection of a rebrightening in the optical afterglow
  5. GRB030725: Optical observations
  6. XRF030723, BVRcIc field photometry update
  7. IPN triangulation of GRB030801 (large error box)
  8. GRB021206 optical counterpart upper limit
  9. IPN triangulation of GRB030731 (annulus)
  10. IBAS GRB Alerts 1011-1017 NOT CONFIRMED
  11. IPN triangulation of GRB030725 (=H2779; small error box)
  12. XRF030723 (=H2777): Second Epoch Magellan Observations
  13. GRB 030725: optical observations.
  14. GRB030725, optical transient observations
  15. IPN triangulation of GRB030726 (large error box)
  16. IPN triangulation of GRB030722 (large error box)
  17. IPN triangulation of GRB030721 (large error box)
  18. XRF030723 Radio Observations
  19. XRF030723(=H2777): Chandra Observations
  20. Magellan Observations of XRF030723 (=H2777)
  21. GRB030723: Upper limits from historical observations
  22. GRB030725, possible optical transient
  23. XRF030723: Palomar observations and proposed counterpart
  24. GRB030725 (=H2779): A Bright GRB Localized by HETE
  25. XRF030723: optical observations
  26. XRF030723 (= H2777): Chandra Observations Scheduled
  27. XRF030723, BVRcIc field photometry
  28. XRF030723, optical observations
  29. GRB030723, optical observations
  30. IBAS GRB Alerts 969 970
  31. IPN triangulation of GRB030717 (annulus)
  32. GRB030329: Subaru Optical Spectroscopy
  33. Triangulation of GRB030715 (single large error box)
  34. Triangulation of GRB030714 (single large error box)
  35. 030716 NOT a GRB
  36. IPN triangulation of GRB030714 (two large error boxes)
  37. IPN triangulation of GRB030715 (two large error boxes)
  38. GRB030329: RTT150 optical observations
  39. GRBlog: Compilation of all GCN Circ. data
  40. IPN detection of renewed activity from SGR1806-20
  41. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  42. IPN triangulation of GRB030710 (annulus)
  43. IPN triangulation of GRB030709 (annulus)
  44. GRB030706 triangulation (single large error box)
  45. IPN triangulation of GRB030706 (annulus)
  46. IPN triangulation of GRB030629 (annulus)
  47. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  48. 030629 NOT a real GRB
  49. IPN triangulation of GRB030626 (single large error box)
  50. IPN triangulation of GRB030626 (two large error boxes)
  51. GRB030418: R optical observations
  52. GRB030329 -- RATAN-600 data in April-May
  53. Final IPN error ellipse for GRB021206 (the polarized GRB)
  54. GRB 021206, Radio afterglow candidate
  55. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  56. IPN triangulation of GRB030607 (annulus)
  57. IPN triangulation of GRB030606 (two alternate error boxes)
  58. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  59. IPN triangulation of GRB030605B (annulus)
  60. GRB 030528: Optical Observations
  61. IPN triangulation of GRB030605 (annulus)
  62. GRB 030528: tentative NIR counterpart
  63. GRB 030528, radio observations
  64. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  65. GRB030329, further radio observations at GMRT
  66. GRB030528, BVRI field photometry
  67. IPN triangulation of GRB030601 (annulus)
  68. GRB030528: Chandra TOO Planned
  69. GRB 030519B: optical observations.
  70. GRB 030329: optical observations
  71. GRB 030329/SN 2003dh: Jitter Episode
  72. GRB 030528, Teramo optical observation
  73. GRB 030528 Bisei optical observation
  74. GRB030528 (H2724): A long GRB localized by HETE
  75. GRB 030329: Correction to GCN 2254
  76. GRB 030329: Optical Observations
  77. GRB 030528: Optical observations at RIKEN
  78. GRB 030528 (=H2724) Kyoto optical observation
  79. IPN triangulation of GRB030523B (annulus)
  80. GRB 030416: Optical Observations
  81. GRB 030329: Planned XMM-Newton Observation
  82. IPN triangulation of GRB030523 (annulus)
  83. GRB 030329: optical photometry at various french observatories
  84. GRB 030329: optical photometry at Belesta observatory (France)
  85. GRB 030329/SN 2003dh: Possible increase in brightness
  86. GRB 030329: HST ACS Observations of the Host
  87. GRB 030329 Optical Observations
  88. GRB 021004: HST observations
  89. GRB030324: Further Observations of the Candidate Optical Afterglow
  90. IPN triangulation of GRB030519B=H2716 (small error box)
  91. GRB 030418: Second Epoch Optical Observations with Magellan
  92. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  93. IPN triangulation of GRB030519 (annulus)
  94. IPN triangulation of GRB030518C (annulus)
  95. IPN triangulation of GRB030518B (annulus)
  96. IPN triangulation of GRB030518A (annulus)
  97. IPN triangulation of GRB030514 (annulus)
  98. IPN triangulation of GRB030513 (annulus)
  99. IPN triangulation of GRB030509B (annulus)
  100. GRB 030329: Optical limit (contemporaneous imaging)

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