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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"

20363 results found.

  1. GRB 031203: Further reports on December 4 observations
  2. GRB 031203: IR NTTobservations do not confirm REM detection
  3. GRB 031203: Apparent Spectral Break
  4. GRB031203: Planned XMM-Newton observation II
  5. GRB 031203: IR REM Observations
  6. GRB031203: Optical Observations
  7. GRB 031203 XMM-Newton observation
  8. GRB 031203: Optical/IR SMARTS Observations
  9. GRB031203: Planned XMM-Newton observation
  10. IPN triangulation of GRB031130 (large error box)
  11. GRB 030329: Planned XMM-Newton Observation
  12. GRB 031111B (= H2925) : Kyoto Optical Observation
  13. IPN triangulation of GRB031114 (large error box)
  14. GRB 031111, optical observations
  15. SN 2003jd (SN/GRB?) -- X-ray Observations
  16. IPN triangulation of GRB031108 (large error box)
  17. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  18. GRB030929/SN2003jd association unlikely based on IPN localiztion
  19. IPN triangulation of GRB031027 (small error box)
  20. Lulin optical follow-up observations of GRB031026
  21. SN 2003jd (SN/GRB?), Radio Observations
  22. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  23. IPN triangulation of GRB031024 (single error box)
  24. IPN triangulation of GRB031020 (large error box)
  25. XRF 030824: additional observations at CFHT
  26. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  27. XRF 030723: Subaru Optical Observations
  28. XRF 030824: Early follow-up observation at Kiso observatory
  29. IPN triangulation of GRB030922B (large error box)
  30. XRF 030723: Detection of the likely host galaxy
  31. IPN triangulation of GRB030921 (large error box)
  32. IPN triangulation of GRB030919 (large error box)
  33. GRB030913: Subaru Optical Observations
  34. GRB030913: OT's limit by MASTER
  35. GRB 030913, optical candidate
  36. GRB 030913, BOOTES observations
  37. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  38. XRF030824: Optical observations
  39. IPN triangulation of GRB030903 (large error box)
  40. IBAS detection of bursts from SGR 1806-20
  41. IPN triangulation of GRB030827 (large error box)
  42. GRB030823: optical observations
  43. GRB030823: optical observation at Tokyo Tech
  44. RAPTOR observations of GRB030823
  45. Lulin follow-up observations of GRB030823
  46. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  47. GRB 030817 = H2808 TAROT optical observations
  48. SGR 1808-20 (=H2802): A Possible new SGR
  49. IPN triangulation of GRB030806 (large burst; large error box)
  50. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  51. XRF030723, BVRcIc field photometry update
  52. IPN triangulation of GRB030801 (large error box)
  53. GRB021206 optical counterpart upper limit
  54. IPN triangulation of GRB030726 (large error box)
  55. IPN triangulation of GRB030721 (large error box)
  56. XRF030723 Radio Observations
  57. XRF 030723: confirmation of fading optical counterpart
  58. XRF030723(=H2777): Chandra Observations
  59. GRB030723: Upper limits from historical observations
  60. XRF030723: Palomar observations and proposed counterpart
  61. GRB030725 (=H2779): A Bright GRB Localized by HETE
  62. XRF030723, BVRcIc field photometry correction
  63. XRF030723, ROTSE-III Early Observations
  64. XRF030723, BVRcIc field photometry
  65. XRF 030723, optical observations
  66. SGR 1806-20, submm observations
  67. RXTE PCA Observations of SGR1806-20 Region
  68. IPN triangulation of GRB030714 (two large error boxes)
  69. IPN triangulation of GRB030715 (two large error boxes)
  70. GRB030706 triangulation (single large error box)
  71. GRB030329, optical observation in May
  72. IPN triangulation of GRB030626 (single large error box)
  73. IPN triangulation of GRB030626 (two large error boxes)
  74. GRB030329 -- RATAN-600 data in April-May
  75. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  76. IPN triangulation of GRB030606 (two alternate error boxes)
  77. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  78. GRB 030528: tentative NIR counterpart
  79. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  80. GRB030528, BVRI field photometry
  81. GRB030329, SPM optical observations
  82. GRB030528: Chandra TOO Planned
  83. GRB030528(=H2724): Revised SXC Localization
  84. GRB 030528 Bisei optical observation
  85. GRB 030528 (=H2724) Kyoto optical observation
  86. GRB 030329 Optical Observations
  87. GRB 021004: HST observations
  88. GRB030324: Further Observations of the Candidate Optical Afterglow
  89. IPN triangulation of GRB030519B=H2716 (small error box)
  90. HETE GRB030329, correction to Rc Observations in Loiano
  91. GRB 030329: Optical limit (contemporaneous imaging)
  92. IPN triangulation of GRB030509 (small errror box)
  93. GRB030429, refiend optical brightness
  94. GRB030418, BVRcIc field photometry
  95. GRB030429, BVRcIc field photometry
  96. GRB030329: RTT150 optical observations and upper limit for a host
  97. GRB030501 triangulation (correction to GCN 2194)
  98. GRB 030429: redshift from VLT spectroscopy
  99. GRB 030429: IR photometry with IRSF/SIRIUS
  100. GRB030501B triangulation (single error box)

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