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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"

28040 results found.

  1. GRB 040403: a long GRB detected with INTEGRAL
  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. GRB 040323: a long GRB detected with INTEGRAL
  6. GRB040223: Deep NIR NTT data re-analysis
  7. GRB 040223: XMM-Newton results
  8. GRB040223, improved XMM position
  9. GRB 031203, possible supernova
  10. MASTER: RXTE GRB040308 optical observation
  11. IBAS results on a burst from SGR1806-20
  12. INTEGRAL detection of activity from SGR1806-20
  13. RXTE GRB040229 optical observation: no candidate
  14. GRB 040228 Optical observations
  15. GRB040228 : KISO optical follow-up observation
  16. GRB 040223: Deep NIR NTT observations
  17. GRB 040223 : Optical observation (non-detection)
  18. XMM-Newton Images of GRB 040223
  19. GRB 040223, VLA observations
  20. GRB 040223: REM IJK Observations
  21. GRB 040223 XMM-Newton observation ...
  22. GRB 031203 XMM-Newton observation
  23. GRB 040223: further offline analysis
  24. GRB031111, optical observations
  25. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  26. GRB031203: Chandra Observations
  27. GRB040106: refined X-ray transient position
  28. SN 2003dh/GRB030329 late-time optical spectroscopy
  29. GRB 031220: Optical observations of Chandra X-ray sources
  30. XMM-Newton Images of GRB 040106
  31. GRB031220: observation at Univercity of Miyazaki
  32. XMM-Newton observation of GRB040106
  33. GRB 040106 : peak flux
  34. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  35. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  36. GRB031220: Palomar Observations
  37. GRB 031220 : Kyoto Optical Observation
  38. GRB 031220: Subaru observation
  39. GRB 031220: Optical observation at Tokyo Tech
  40. GRB 2974 follow-up observations
  41. GRB031203, improved XMM position
  42. GRB 021203: A Normal GRB viewed far off axis?
  43. XMM-Newton Observations of GRB031203: Preliminary Images
  44. GRB 031203: Variable Radio Source
  45. GRB 031203: Magellan spectrum of possible GRB host
  46. GRB 031203: Optical/IR Astrometry
  47. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  48. XMM-Newton Observation of GRB031203
  49. GRB031203: K' Photometry of the likely GRB host
  50. XMM-Newton Observation of GRB031203
  51. GRB 031203: IR NTTobservations do not confirm REM detection
  52. GRB031203 : Optical Observation of Lulin Observatory
  53. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  54. GRB 031203: Apparent Spectral Break
  55. GRB031203: Planned XMM-Newton observation II
  56. GRB 031203: IR REM Observations
  57. GRB031203: Optical Observations
  58. GRB 031203 XMM-Newton observation
  59. GRB031203: Planned XMM-Newton observation
  60. GRB 031203: further analysis of INTEGRAL data
  61. GRB 030329: Planned XMM-Newton Observation
  62. GRB 031111B (= H2925) : Kyoto Optical Observation
  63. IPN triangulation of GRB031114 (large error box)
  64. GRB 031111, optical observations
  65. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  66. GRB030929/SN2003jd association unlikely based on IPN localiztion
  67. IPN triangulation of GRB031027 (small error box)
  68. Lulin optical follow-up observations of GRB031026
  69. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  70. IPN triangulation of GRB031024 (single error box)
  71. IPN triangulation of GRB031024 (annulus)
  72. IPN triangulation of GRB031020 (large error box)
  73. XRF 030824: additional observations at CFHT
  74. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  75. XRF 030723: Subaru Optical Observations
  76. XRF 030824: Early follow-up observation at Kiso observatory
  77. XRF 030824: observations at CFHT
  78. IPN triangulation of GRB030922B (large error box)
  79. XRF 030723: Detection of the likely host galaxy
  80. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  81. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  82. IPN triangulation of GRB030921 (large error box)
  83. IPN triangulation of GRB030919 (large error box)
  84. GRB030913: Subaru Optical Observations
  85. GRB 030913, optical candidate
  86. GRB 030913, BOOTES observations
  87. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  88. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  89. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  90. XRF030824: Optical observations
  91. IPN triangulation of GRB030903 (large error box)
  92. IPN triangulation of GRB030827 (large error box)
  93. GRB030823: optical observations
  94. GRB030823: optical observation at Tokyo Tech
  95. Lulin follow-up observations of GRB030823
  96. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  97. IPN detection of continued activity from SGR1806-20
  98. GRB 030817 = H2808 TAROT optical observations
  99. SGR 1808-20 (=H2802): A Possible new SGR
  100. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed

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