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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"

21769 results found.

  1. MASTER: RXTE GRB040308 optical observation
  2. IBAS results on a burst from SGR1806-20
  3. IPN triangulation of GRB040228 (H3066, H3067)
  4. GRB040228 : KISO optical follow-up observation
  5. GRB 040223: Deep NIR NTT observations
  6. GRB 040223 : Optical observation (non-detection)
  7. XMM-Newton Images of GRB 040223
  8. GRB 040223, VLA observations
  9. GRB 040223: REM IJK Observations
  10. GRB 040223 XMM-Newton observation ...
  11. GRB 031203 XMM-Newton observation
  12. GRB031111, optical observations
  13. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  14. GRB040106: refined X-ray transient position
  15. GRB040106, Radio Observations
  16. GRB040106, likely optical afterglow
  17. GRB 031220: Optical observations of Chandra X-ray sources
  18. XMM-Newton Images of GRB 040106
  19. GRB031220: observation at Univercity of Miyazaki
  20. XMM-Newton observation of GRB040106
  21. IPN triangulation of an intermediate burst from SGR1806-20
  22. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  23. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  24. GRB031220: Palomar Observations
  25. GRB 031220 : Kyoto Optical Observation
  26. GRB 031220: Subaru observation
  27. GRB 031220: Optical observation at Tokyo Tech
  28. GRB 2974 follow-up observations
  29. GRB031203, improved XMM position
  30. GRB 031203: SMARTS optical monitoring
  31. XMM-Newton Observations of GRB031203: Preliminary Images
  32. GRB 031203: Optical/IR Astrometry
  33. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  34. XMM-Newton Observation of GRB031203
  35. XMM-Newton Observation of GRB031203
  36. GRB 031203: IR NTTobservations do not confirm REM detection
  37. GRB031203 : Optical Observation of Lulin Observatory
  38. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  39. GRB031203: Planned XMM-Newton observation II
  40. GRB 031203: IR REM Observations
  41. GRB031203: Optical Observations
  42. GRB 031203 XMM-Newton observation
  43. GRB 031203: Optical/IR SMARTS Observations
  44. GRB031203: Planned XMM-Newton observation
  45. GRB 030329: Planned XMM-Newton Observation
  46. GRB 031111B (= H2925) : Kyoto Optical Observation
  47. GRB 031111, Radio observations
  48. IPN triangulation of GRB031114 (large error box)
  49. GRB 031111, optical observations
  50. IPN triangulation of GRB031108 (large error box)
  51. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  52. GRB030929/SN2003jd association unlikely based on IPN localiztion
  53. Lulin optical follow-up observations of GRB031026
  54. IPN triangulation of GRB031024 (single error box)
  55. IPN triangulation of GRB031024 (annulus)
  56. XRF 030824: additional observations at CFHT
  57. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  58. IPN triangulation of GRB031007 (two large error boxes)
  59. XRF 030723: Subaru Optical Observations
  60. XRF 030824: Early follow-up observation at Kiso observatory
  61. XRF 030723: Detection of the likely host galaxy
  62. IPN triangulation of GRB030921 (large error box)
  63. GRB030913: Subaru Optical Observations
  64. GRB 030913, optical candidate
  65. GRB 030913, BOOTES observations
  66. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  67. XRF030824: Optical observations
  68. IPN triangulation of GRB030827 (large error box)
  69. GRB030823: optical observation at Tokyo Tech
  70. Lulin follow-up observations of GRB030823
  71. IPN triangulation of GRB030821 (=H2814; refined error box)
  72. GRB 030817 = H2808 TAROT optical observations
  73. SGR 1808-20 (=H2802): A Possible new SGR
  74. IPN triangulation of GRB030806 (large burst; large error box)
  75. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  76. IPN/HETE summary of recent bursts from SGR1806-20
  77. XRF030723, BVRcIc field photometry update
  78. GRB021206 optical counterpart upper limit
  79. IPN triangulation of GRB030725 (=H2779; small error box)
  80. XRF030723 Radio Observations
  81. XRF 030723: confirmation of fading optical counterpart
  82. XRF030723(=H2777): Chandra Observations
  83. GRB030723: Upper limits from historical observations
  84. XRF030723: Palomar observations and proposed counterpart
  85. GRB030725 (=H2779): A Bright GRB Localized by HETE
  86. XRF030723, BVRcIc field photometry correction
  87. XRF030723, ROTSE-III Early Observations
  88. XRF030723, BVRcIc field photometry
  89. XRF 030723, optical observations
  90. XRF030723, optical observations
  91. Konus-Wind detection of the bursts from SGR1806-20 region
  92. SGR 1806-20, submm observations
  93. RXTE PCA Observations of SGR1806-20 Region
  94. IPN triangulation of GRB030714 (two large error boxes)
  95. IPN triangulation of GRB030715 (two large error boxes)
  96. GRBlog: Compilation of all GCN Circ. data
  97. GRB030329, optical observation in May
  98. IPN triangulation of GRB030626 (single large error box)
  99. IPN triangulation of GRB030626 (two large error boxes)
  100. GRB030329 -- RATAN-600 data in April-May

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