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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"
  1. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  2. IPN triangulation of GRB030717 (annulus)
  3. RXTE PCA Observations of SGR1806-20 Region
  4. GRB030329: Subaru Optical Spectroscopy
  5. Triangulation of GRB030715 (single large error box)
  6. Triangulation of GRB030714 (single large error box)
  7. 030716 NOT a GRB
  8. IPN triangulation of GRB030714 (two large error boxes)
  9. IPN triangulation of GRB030715 (two large error boxes)
  10. GRB030329: RTT150 optical observations
  11. GRBlog: Compilation of all GCN Circ. data
  12. IPN detection of renewed activity from SGR1806-20
  13. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  14. IPN triangulation of GRB030710 (annulus)
  15. IPN triangulation of GRB030709 (annulus)
  16. GRB030706 triangulation (single large error box)
  17. IPN triangulation of GRB030706 (annulus)
  18. IPN triangulation of GRB030629 (annulus)
  19. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  20. 030629 NOT a real GRB
  21. GRB030329, optical observation in May
  22. IPN triangulation of GRB030626 (single large error box)
  23. IPN triangulation of GRB030626 (two large error boxes)
  24. GRB030329: second XMM-Newton observation
  25. GRB030418: R optical observations
  26. HETE detection of burst from SGR1806-20
  27. GRB030329 -- RATAN-600 data in April-May
  28. Final IPN error ellipse for GRB021206 (the polarized GRB)
  29. GRB 021206, Radio afterglow candidate
  30. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  31. IPN triangulation of GRB030607 (annulus)
  32. IPN triangulation of GRB030606 (two alternate error boxes)
  33. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  34. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  35. IPN triangulation of GRB030605B (annulus)
  36. GRB 030528: Optical Observations
  37. IPN triangulation of GRB030605 (annulus)
  38. GRB 030528: tentative NIR counterpart
  39. GRB 030528, radio observations
  40. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  41. GRB030329, further radio observations at GMRT
  42. GRB030528, BVRI field photometry
  43. IPN triangulation of GRB030601 (annulus)
  44. GRB030329, SPM optical observations
  45. GRB030528: Chandra TOO Planned
  46. GRB 030519B: optical observations.
  47. MASTER: optical observation GRB030601
  48. GRB030528(=H2724): Revised SXC Localization
  49. GRB 030329: optical observations
  50. GRB 030329/SN 2003dh: Jitter Episode
  51. GRB 030528, Teramo optical observation
  52. GRB 030528 Bisei optical observation
  53. GRB030528 (H2724): A long GRB localized by HETE
  54. GRB 030329: Correction to GCN 2254
  55. GRB 030329: Optical Observations
  56. GRB 030528: Optical observations at RIKEN
  57. GRB 030528 (=H2724) Kyoto optical observation
  58. IPN triangulation of GRB030523B (annulus)
  59. GRB 030416: Optical Observations
  60. GRB 030329: Planned XMM-Newton Observation
  61. IPN triangulation of GRB030523 (annulus)
  62. GRB 030329: optical photometry at various french observatories
  63. GRB 030329: optical photometry at Belesta observatory (France)
  64. GRB030329, Optical observations
  65. GRB 030329/SN 2003dh: Possible increase in brightness
  66. GRB 030329: HST ACS Observations of the Host
  67. GRB 030329 Optical Observations
  68. GRB030329: XMM-Newton observation
  69. GRB 021004: HST observations
  70. GRB030324: Further Observations of the Candidate Optical Afterglow
  71. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  72. IPN triangulation of GRB030519B=H2716 (small error box)
  73. GRB 030418: Second Epoch Optical Observations with Magellan
  74. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  75. IPN triangulation of GRB030519 (annulus)
  76. IPN triangulation of GRB030518C (annulus)
  77. IPN triangulation of GRB030518B (annulus)
  78. IPN triangulation of GRB030518A (annulus)
  79. IPN triangulation of GRB030514 (annulus)
  80. HETE GRB030329, correction to Rc Observations in Loiano
  81. IPN triangulation of GRB030513 (annulus)
  82. IPN triangulation of GRB030509B (annulus)
  83. GRB 030329: Optical limit (contemporaneous imaging)
  84. GRB 030501: final TAROT limits
  85. IPN triangulation of GRB030509 (small errror box)
  86. IPN triangulation of GRB030509 - correction
  87. IPN triangulation of GRB030509 (single error box)
  88. GRB030329: RTT150 optical observations
  89. GRB030329, BVRI photometry
  90. GRB030429, refiend optical brightness
  91. GRB 030329: Optical limit (contemporaneous photography)
  92. GRB030418, BVRcIc field photometry
  93. GRB 030429: Redshift of neighbor galaxy
  94. GRB030429, BVRcIc field photometry
  95. GRB030429: RTT150 optical obs., correction to GCN 2208
  96. GRB 030329: High-Resolution Spectroscopy of the Host
  97. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  98. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  99. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  100. GRB030429: RTT150 optical observations, a possible host galaxy

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