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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"

21768 results found.

  1. IBAS results on a burst from SGR1806-20
  2. IPN triangulation of GRB040228 (H3066, H3067)
  3. GRB040228 : KISO optical follow-up observation
  4. GRB 040223: Deep NIR NTT observations
  5. GRB 040223 : Optical observation (non-detection)
  6. XMM-Newton Images of GRB 040223
  7. GRB 040223, VLA observations
  8. GRB 040223: REM IJK Observations
  9. GRB 040223 XMM-Newton observation ...
  10. GRB 031203 XMM-Newton observation
  11. GRB031111, optical observations
  12. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  13. GRB040106: refined X-ray transient position
  14. GRB040106, Radio Observations
  15. GRB040106, likely optical afterglow
  16. GRB 031220: Optical observations of Chandra X-ray sources
  17. XMM-Newton Images of GRB 040106
  18. GRB031220: observation at Univercity of Miyazaki
  19. XMM-Newton observation of GRB040106
  20. IPN triangulation of an intermediate burst from SGR1806-20
  21. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  22. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  23. GRB031220: Palomar Observations
  24. GRB 031220 : Kyoto Optical Observation
  25. GRB 031220: Subaru observation
  26. GRB 031220: Optical observation at Tokyo Tech
  27. GRB 2974 follow-up observations
  28. GRB031203, improved XMM position
  29. GRB 031203: SMARTS optical monitoring
  30. XMM-Newton Observations of GRB031203: Preliminary Images
  31. GRB 031203: Optical/IR Astrometry
  32. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  33. XMM-Newton Observation of GRB031203
  34. XMM-Newton Observation of GRB031203
  35. GRB 031203: IR NTTobservations do not confirm REM detection
  36. GRB031203 : Optical Observation of Lulin Observatory
  37. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  38. GRB031203: Planned XMM-Newton observation II
  39. GRB 031203: IR REM Observations
  40. GRB031203: Optical Observations
  41. GRB 031203 XMM-Newton observation
  42. GRB 031203: Optical/IR SMARTS Observations
  43. GRB031203: Planned XMM-Newton observation
  44. GRB 030329: Planned XMM-Newton Observation
  45. GRB 031111B (= H2925) : Kyoto Optical Observation
  46. GRB 031111, Radio observations
  47. IPN triangulation of GRB031114 (large error box)
  48. GRB 031111, optical observations
  49. IPN triangulation of GRB031108 (large error box)
  50. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  51. GRB030929/SN2003jd association unlikely based on IPN localiztion
  52. Lulin optical follow-up observations of GRB031026
  53. IPN triangulation of GRB031024 (single error box)
  54. IPN triangulation of GRB031024 (annulus)
  55. XRF 030824: additional observations at CFHT
  56. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  57. IPN triangulation of GRB031007 (two large error boxes)
  58. XRF 030723: Subaru Optical Observations
  59. XRF 030824: Early follow-up observation at Kiso observatory
  60. XRF 030723: Detection of the likely host galaxy
  61. IPN triangulation of GRB030921 (large error box)
  62. GRB030913: Subaru Optical Observations
  63. GRB 030913, optical candidate
  64. GRB 030913, BOOTES observations
  65. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  66. XRF030824: Optical observations
  67. IPN triangulation of GRB030827 (large error box)
  68. GRB030823: optical observation at Tokyo Tech
  69. Lulin follow-up observations of GRB030823
  70. IPN triangulation of GRB030821 (=H2814; refined error box)
  71. GRB 030817 = H2808 TAROT optical observations
  72. SGR 1808-20 (=H2802): A Possible new SGR
  73. IPN triangulation of GRB030806 (large burst; large error box)
  74. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  75. IPN/HETE summary of recent bursts from SGR1806-20
  76. XRF030723, BVRcIc field photometry update
  77. GRB021206 optical counterpart upper limit
  78. IPN triangulation of GRB030725 (=H2779; small error box)
  79. XRF030723 Radio Observations
  80. XRF 030723: confirmation of fading optical counterpart
  81. XRF030723(=H2777): Chandra Observations
  82. GRB030723: Upper limits from historical observations
  83. XRF030723: Palomar observations and proposed counterpart
  84. GRB030725 (=H2779): A Bright GRB Localized by HETE
  85. XRF030723, BVRcIc field photometry correction
  86. XRF030723, ROTSE-III Early Observations
  87. XRF030723, BVRcIc field photometry
  88. XRF 030723, optical observations
  89. XRF030723, optical observations
  90. Konus-Wind detection of the bursts from SGR1806-20 region
  91. SGR 1806-20, submm observations
  92. RXTE PCA Observations of SGR1806-20 Region
  93. IPN triangulation of GRB030714 (two large error boxes)
  94. IPN triangulation of GRB030715 (two large error boxes)
  95. GRBlog: Compilation of all GCN Circ. data
  96. GRB030329, optical observation in May
  97. IPN triangulation of GRB030626 (single large error box)
  98. IPN triangulation of GRB030626 (two large error boxes)
  99. GRB030329 -- RATAN-600 data in April-May
  100. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch

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