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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"

26367 results found.

  1. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  2. XRF 030723: Subaru Optical Observations
  3. XRF 030824: Early follow-up observation at Kiso observatory
  4. XRF 030824: observations at CFHT
  5. IPN triangulation of GRB030922B (large error box)
  6. XRF 030723: Detection of the likely host galaxy
  7. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  8. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  9. IPN triangulation of GRB030921 (large error box)
  10. IPN triangulation of GRB030919 (large error box)
  11. GRB030913: Subaru Optical Observations
  12. GRB 030913, optical candidate
  13. GRB 030913, BOOTES observations
  14. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  15. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  16. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  17. XRF030824: Optical observations
  18. IPN triangulation of GRB030903 (large error box)
  19. IPN triangulation of GRB030827 (large error box)
  20. GRB030823: optical observations
  21. GRB030823: optical observation at Tokyo Tech
  22. Lulin follow-up observations of GRB030823
  23. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  24. IPN detection of continued activity from SGR1806-20
  25. GRB 030817 = H2808 TAROT optical observations
  26. SGR 1808-20 (=H2802): A Possible new SGR
  27. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  28. XRF 030723: Detection of a rebrightening in the optical afterglow
  29. XRF030723, BVRcIc field photometry update
  30. IPN triangulation of GRB030801 (large error box)
  31. GRB021206 optical counterpart upper limit
  32. IPN triangulation of GRB030726 (large error box)
  33. IPN triangulation of GRB030721 (large error box)
  34. XRF030723 Radio Observations
  35. XRF 030723: confirmation of fading optical counterpart
  36. XRF030723(=H2777): Chandra Observations
  37. GRB030723: Upper limits from historical observations
  38. XRF030723: Palomar observations and proposed counterpart
  39. GRB030725 (=H2779): A Bright GRB Localized by HETE
  40. XRF030723 (= H2777): Chandra Observations Scheduled
  41. XRF030723, BVRcIc field photometry correction
  42. XRF030723, ROTSE-III Early Observations
  43. XRF030723, BVRcIc field photometry
  44. XRF 030723, optical observations
  45. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  46. Konus-Wind detection of the bursts from SGR1806-20 region
  47. SGR 1806-20, submm observations
  48. RXTE PCA Observations of SGR1806-20 Region
  49. IPN triangulation of GRB030714 (two large error boxes)
  50. IPN triangulation of GRB030715 (two large error boxes)
  51. GRB030706 triangulation (single large error box)
  52. GRB030329, optical observation in May
  53. IPN triangulation of GRB030626 (single large error box)
  54. IPN triangulation of GRB030626 (two large error boxes)
  55. GRB030329: second XMM-Newton observation
  56. GRB030329 -- RATAN-600 data in April-May
  57. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  58. IPN triangulation of GRB030606 (two alternate error boxes)
  59. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  60. GRB 030528: tentative NIR counterpart
  61. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  62. GRB030528, BVRI field photometry
  63. GRB030329, SPM optical observations
  64. GRB030528: Chandra TOO Planned
  65. GRB030528(=H2724): Revised SXC Localization
  66. GRB 030528 Bisei optical observation
  67. GRB030528 (H2724): A long GRB localized by HETE
  68. GRB 030329: Correction to GCN 2254
  69. GRB 030329: Optical Observations
  70. GRB 030528 (=H2724) Kyoto optical observation
  71. GRB 030416: Optical Observations
  72. GRB 030329 Optical Observations
  73. GRB030329: XMM-Newton observation
  74. GRB 021004: HST observations
  75. GRB030324: Further Observations of the Candidate Optical Afterglow
  76. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  77. IPN triangulation of GRB030519B=H2716 (small error box)
  78. HETE GRB030329, correction to Rc Observations in Loiano
  79. GRB 030329: Optical limit (contemporaneous imaging)
  80. IPN triangulation of GRB030509 (small errror box)
  81. GRB030329, BVRI photometry
  82. GRB030429, refiend optical brightness
  83. GRB 030329: Optical limit (contemporaneous photography)
  84. GRB030418, BVRcIc field photometry
  85. GRB030429, BVRcIc field photometry
  86. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  87. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  88. GRB030329: RTT150 optical observations and upper limit for a host
  89. GRB030501, optical observation
  90. GRB030501 triangulation (correction to GCN 2194)
  91. GRB030329: RTT150 optical observations and upper limit for a host
  92. GRB 030429: redshift from VLT spectroscopy
  93. GRB030501B triangulation (single error box)
  94. GRB 030329, BVRI photometry
  95. GRB030429: Optical Observations
  96. GRB030501: TAROT candidate afterglow present in archival images
  97. GRB 030429: confirmation of afterglow candidate
  98. GRB 030329 Oprical observations in Rozhen observatory
  99. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  100. IPN triangulation of GRB030425 (single error box)

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