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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"

32595 results found.

  1. XRF030723 (=H2777): Second Epoch Magellan Observations
  2. GRB 030725: optical observations.
  3. GRB030725, optical transient observations
  4. IPN triangulation of GRB030726 (large error box)
  5. IPN triangulation of GRB030722 (large error box)
  6. IPN triangulation of GRB030721 (large error box)
  7. XRF030723 Radio Observations
  8. XRF030723(=H2777): Chandra Observations
  9. XRF 030723: VLT spectra
  10. Magellan Observations of XRF030723 (=H2777)
  11. GRB030723: Upper limits from historical observations
  12. GRB030725, possible optical transient
  13. XRF030723: Palomar observations and proposed counterpart
  14. GRB030725 (=H2779): A Bright GRB Localized by HETE
  15. XRF030723: optical observations
  16. XRF030723 (= H2777): Chandra Observations Scheduled
  17. XRF030723, BVRcIc field photometry
  18. XRF030723, optical observations
  19. GRB030723, optical observations
  20. IBAS GRB Alerts 969 970
  21. IPN triangulation of GRB030717 (annulus)
  22. GRB030329: Subaru Optical Spectroscopy
  23. Triangulation of GRB030715 (single large error box)
  24. Triangulation of GRB030714 (single large error box)
  25. 030716 NOT a GRB
  26. IPN triangulation of GRB030714 (two large error boxes)
  27. IPN triangulation of GRB030715 (two large error boxes)
  28. GRB030329: RTT150 optical observations
  29. GRBlog: Compilation of all GCN Circ. data
  30. IPN detection of renewed activity from SGR1806-20
  31. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  32. IPN triangulation of GRB030710 (annulus)
  33. IPN triangulation of GRB030709 (annulus)
  34. GRB030706 triangulation (single large error box)
  35. IPN triangulation of GRB030706 (annulus)
  36. IPN triangulation of GRB030629 (annulus)
  37. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  38. 030629 NOT a real GRB
  39. IPN triangulation of GRB030626 (single large error box)
  40. IPN triangulation of GRB030626 (two large error boxes)
  41. GRB030418: R optical observations
  42. GRB030329 -- RATAN-600 data in April-May
  43. Final IPN error ellipse for GRB021206 (the polarized GRB)
  44. GRB 021206, Radio afterglow candidate
  45. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  46. IPN triangulation of GRB030607 (annulus)
  47. IPN triangulation of GRB030606 (two alternate error boxes)
  48. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  49. IPN triangulation of GRB030605B (annulus)
  50. GRB 030528: Optical Observations
  51. IPN triangulation of GRB030605 (annulus)
  52. GRB 030528: tentative NIR counterpart
  53. GRB 030528, radio observations
  54. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  55. GRB030329, further radio observations at GMRT
  56. GRB030528, BVRI field photometry
  57. IPN triangulation of GRB030601 (annulus)
  58. GRB030528: Chandra TOO Planned
  59. GRB 030519B: optical observations.
  60. GRB 030329: optical observations
  61. GRB 030329/SN 2003dh: Jitter Episode
  62. GRB 030528, Teramo optical observation
  63. GRB 030528 Bisei optical observation
  64. GRB030528 (H2724): A long GRB localized by HETE
  65. GRB 030329: Correction to GCN 2254
  66. GRB 030329: Optical Observations
  67. GRB 030528: Optical observations at RIKEN
  68. GRB 030528 (=H2724) Kyoto optical observation
  69. IPN triangulation of GRB030523B (annulus)
  70. GRB 030416: Optical Observations
  71. GRB 030329: Planned XMM-Newton Observation
  72. IPN triangulation of GRB030523 (annulus)
  73. GRB 030329: optical photometry at various french observatories
  74. GRB 030329: optical photometry at Belesta observatory (France)
  75. GRB 030329/SN 2003dh: Possible increase in brightness
  76. GRB 030329: HST ACS Observations of the Host
  77. GRB 030329 Optical Observations
  78. GRB 021004: HST observations
  79. GRB030324: Further Observations of the Candidate Optical Afterglow
  80. IPN triangulation of GRB030519B=H2716 (small error box)
  81. GRB 030418: Second Epoch Optical Observations with Magellan
  82. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  83. IPN triangulation of GRB030519 (annulus)
  84. IPN triangulation of GRB030518C (annulus)
  85. IPN triangulation of GRB030518B (annulus)
  86. IPN triangulation of GRB030518A (annulus)
  87. IPN triangulation of GRB030514 (annulus)
  88. IPN triangulation of GRB030513 (annulus)
  89. IPN triangulation of GRB030509B (annulus)
  90. GRB 030329: Optical limit (contemporaneous imaging)
  91. GRB 030501: final TAROT limits
  92. IPN triangulation of GRB030509 (small errror box)
  93. IPN triangulation of GRB030509 - correction
  94. IPN triangulation of GRB030509 (single error box)
  95. GRB030329: RTT150 optical observations
  96. GRB 030329: Optical limit (contemporaneous photography)
  97. GRB030418, BVRcIc field photometry
  98. GRB 030429: Redshift of neighbor galaxy
  99. GRB030429, BVRcIc field photometry
  100. GRB 030329: High-Resolution Spectroscopy of the Host

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