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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').
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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"

20857 results found.

  1. GRB 040329: hard burst detected by Konus-Wind and Helicon - Coronas-F
  2. GRB040323: NIR Observations and Variable Object
  3. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  4. GRB 040323, a dark GRB ?
  5. short hard GRB 040322
  6. GRB040223, improved XMM position
  7. GRB 031203, possible supernova
  8. MASTER: RXTE GRB040308 optical observation
  9. IBAS results on a burst from SGR1806-20
  10. RXTE GRB040229 optical observation: no candidate
  11. IPN triangulation of GRB040228 (H3066, H3067)
  12. GRB040228 : KISO optical follow-up observation
  13. GRB 040223: Deep NIR NTT observations
  14. GRB 040223 : Optical observation (non-detection)
  15. XMM-Newton Images of GRB 040223
  16. GRB 040223, VLA observations
  17. GRB 040223: REM IJK Observations
  18. GRB 040223 XMM-Newton observation ...
  19. GRB 031203 XMM-Newton observation
  20. GRB 040223: further offline analysis
  21. GRB031111, optical observations
  22. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  23. GRB040106: refined X-ray transient position
  24. GRB 031220: Optical observations of Chandra X-ray sources
  25. XMM-Newton Images of GRB 040106
  26. GRB031220: observation at Univercity of Miyazaki
  27. XMM-Newton observation of GRB040106
  28. GRB 040106 : a long GRB detected with INTEGRAL
  29. IPN triangulation of an intermediate burst from SGR1806-20
  30. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  31. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  32. GRB031225a triangulation (annulus)
  33. IPN triangulation of GRB031219 (large error box)
  34. GRB 031220 : Kyoto Optical Observation
  35. GRB 031220: Subaru observation
  36. GRB 031220: Optical observation at Tokyo Tech
  37. IPN triangulation of GRB031214 (short/hard; very intense; small error box)
  38. GRB 2974 follow-up observations
  39. GRB031203, improved XMM position
  40. GRB 031203: Discovery of a dust echo
  41. GRB031214 triangulation (annulus), [repost of GCN2487, subject corrected]
  42. GRB030921 triangulation (annulus)
  43. XMM-Newton Observations of GRB031203: Preliminary Images
  44. IPN/HETE localization of GRB031203B (=H2949; large error box)
  45. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  46. XMM-Newton Observation of GRB031203
  47. XMM-Newton Observation of GRB031203
  48. GRB 031203: IR NTTobservations do not confirm REM detection
  49. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  50. GRB 031203: Apparent Spectral Break
  51. GRB031203: Planned XMM-Newton observation II
  52. GRB 031203: IR REM Observations
  53. GRB031203: Optical Observations
  54. GRB 031203 XMM-Newton observation
  55. GRB 031203: Optical/IR SMARTS Observations
  56. GRB031203: Planned XMM-Newton observation
  57. IPN triangulation of GRB031127A and B (quasi-simultaneous; large error boxes)
  58. IPN triangulation of GRB031201 (large error box)
  59. IPN triangulation of GRB031130 (large error box)
  60. GRB 030329: Planned XMM-Newton Observation
  61. IPN triangulation of GRB031120 (two large error boxes)
  62. GRB 031111B (= H2925) : Kyoto Optical Observation
  63. IPN detection of activity from SGR1806-20
  64. IPN triangulation of GRB031114 (large error box)
  65. IPN triangulation of GRB031107 (two large error boxes)
  66. GRB 031111, optical observations
  67. IPN triangulation of GRB031111 (=H2924): small error box
  68. IPN triangulation of GRB031108 (large error box)
  69. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  70. GRB030929/SN2003jd association unlikely based on IPN localiztion
  71. IPN triangulation of GRB031027 (small error box)
  72. IPN triangulation of GRB031026B (large error box)
  73. Lulin optical follow-up observations of GRB031026
  74. SN 2003jd (SN/GRB?), Radio Observations
  75. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  76. GRB 031026: Further Ic Observations
  77. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  78. IPN triangulation of GRB031024 (single error box)
  79. GRB031026 : KISO optical follow-up observation
  80. IPN triangulation of GRB031024 (annulus)
  81. IPN triangulation of GRB031020 (large error box)
  82. GRB030329: radio observations at RT-22 (CrAO)
  83. IPN triangulation of GRB031016 (two large error boxes)
  84. IPN triangulation of GRB031014 (annulus)
  85. XRF 030824: additional observations at CFHT
  86. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  87. IPN triangulation of GRB031008 (annulus)
  88. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  89. IPN detection of continued activity from SGR1806-20
  90. IPN triangulation of GRB031007 (two large error boxes)
  91. XRF 030723: Subaru Optical Observations
  92. IPN triangulation of GRB031004B (annulus)
  93. IPN triangulation of GRB030929 (short/hard; annulus)
  94. XRF 030824: Early follow-up observation at Kiso observatory
  95. IPN triangulation of GRB030926 (short/hard; large error box)
  96. IPN triangulation of GRB030922B (large error box)
  97. XRF 030723: Detection of the likely host galaxy
  98. IPN triangulation of GRB030922A (large error box)
  99. IPN triangulation of GRB030921 (large error box)
  100. IPN triangulation of GRB030919 (large error box)

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