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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"

32789 results found.

  1. GRB 030725: optical observations.
  2. GRB030725, optical transient observations
  3. IPN triangulation of GRB030726 (large error box)
  4. IPN triangulation of GRB030722 (large error box)
  5. IPN triangulation of GRB030721 (large error box)
  6. XRF030723 Radio Observations
  7. XRF030723(=H2777): Chandra Observations
  8. Magellan Observations of XRF030723 (=H2777)
  9. GRB030723: Upper limits from historical observations
  10. GRB030725, possible optical transient
  11. XRF030723: Palomar observations and proposed counterpart
  12. GRB030725 (=H2779): A Bright GRB Localized by HETE
  13. XRF030723: optical observations
  14. XRF030723 (= H2777): Chandra Observations Scheduled
  15. XRF030723, BVRcIc field photometry
  16. XRF030723, optical observations
  17. GRB030723, optical observations
  18. IBAS GRB Alerts 969 970
  19. IPN triangulation of GRB030717 (annulus)
  20. GRB030329: Subaru Optical Spectroscopy
  21. Triangulation of GRB030715 (single large error box)
  22. Triangulation of GRB030714 (single large error box)
  23. 030716 NOT a GRB
  24. IPN triangulation of GRB030714 (two large error boxes)
  25. IPN triangulation of GRB030715 (two large error boxes)
  26. GRB030329: RTT150 optical observations
  27. GRBlog: Compilation of all GCN Circ. data
  28. IPN detection of renewed activity from SGR1806-20
  29. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  30. IPN triangulation of GRB030710 (annulus)
  31. IPN triangulation of GRB030709 (annulus)
  32. GRB030706 triangulation (single large error box)
  33. IPN triangulation of GRB030706 (annulus)
  34. IPN triangulation of GRB030629 (annulus)
  35. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  36. 030629 NOT a real GRB
  37. IPN triangulation of GRB030626 (single large error box)
  38. IPN triangulation of GRB030626 (two large error boxes)
  39. GRB030418: R optical observations
  40. GRB030329 -- RATAN-600 data in April-May
  41. Final IPN error ellipse for GRB021206 (the polarized GRB)
  42. GRB 021206, Radio afterglow candidate
  43. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  44. IPN triangulation of GRB030607 (annulus)
  45. IPN triangulation of GRB030606 (two alternate error boxes)
  46. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  47. IPN triangulation of GRB030605B (annulus)
  48. GRB 030528: Optical Observations
  49. IPN triangulation of GRB030605 (annulus)
  50. GRB 030528: tentative NIR counterpart
  51. GRB 030528, radio observations
  52. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  53. GRB030329, further radio observations at GMRT
  54. GRB030528, BVRI field photometry
  55. IPN triangulation of GRB030601 (annulus)
  56. GRB030528: Chandra TOO Planned
  57. GRB 030519B: optical observations.
  58. GRB 030329: optical observations
  59. GRB 030329/SN 2003dh: Jitter Episode
  60. GRB 030528, Teramo optical observation
  61. GRB 030528 Bisei optical observation
  62. GRB030528 (H2724): A long GRB localized by HETE
  63. GRB 030329: Correction to GCN 2254
  64. GRB 030329: Optical Observations
  65. GRB 030528: Optical observations at RIKEN
  66. GRB 030528 (=H2724) Kyoto optical observation
  67. IPN triangulation of GRB030523B (annulus)
  68. GRB 030416: Optical Observations
  69. GRB 030329: Planned XMM-Newton Observation
  70. IPN triangulation of GRB030523 (annulus)
  71. GRB 030329: optical photometry at various french observatories
  72. GRB 030329: optical photometry at Belesta observatory (France)
  73. GRB 030329/SN 2003dh: Possible increase in brightness
  74. GRB 030329: HST ACS Observations of the Host
  75. GRB 030329 Optical Observations
  76. GRB 021004: HST observations
  77. GRB030324: Further Observations of the Candidate Optical Afterglow
  78. IPN triangulation of GRB030519B=H2716 (small error box)
  79. GRB 030418: Second Epoch Optical Observations with Magellan
  80. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  81. IPN triangulation of GRB030519 (annulus)
  82. IPN triangulation of GRB030518C (annulus)
  83. IPN triangulation of GRB030518B (annulus)
  84. IPN triangulation of GRB030518A (annulus)
  85. IPN triangulation of GRB030514 (annulus)
  86. IPN triangulation of GRB030513 (annulus)
  87. IPN triangulation of GRB030509B (annulus)
  88. GRB 030329: Optical limit (contemporaneous imaging)
  89. GRB 030501: final TAROT limits
  90. IPN triangulation of GRB030509 (small errror box)
  91. IPN triangulation of GRB030509 - correction
  92. IPN triangulation of GRB030509 (single error box)
  93. GRB030329: RTT150 optical observations
  94. GRB 030329: Optical limit (contemporaneous photography)
  95. GRB030418, BVRcIc field photometry
  96. GRB 030429: Redshift of neighbor galaxy
  97. GRB030429, BVRcIc field photometry
  98. GRB 030329: High-Resolution Spectroscopy of the Host
  99. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  100. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM

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