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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"

24873 results found.

  1. GRB 040624: optical observations at TNG and VLT
  2. MASTER: GRB 040624 optical observation after 0,48d
  3. GRB 040624, optical observations
  4. GRB 040624 - A long GRB detected with INTEGRAL
  5. GRB 030329: Rebrightening of hyperluminal ejecta.
  6. IPN Summary of SGR1806-20 Activity in 2004
  7. SGR 1806-20: no IR variability of the proposed counterparts
  8. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  9. SGR 1806-20, potential NIR counterpart
  10. GRB 040606: Optical observations
  11. MASTER: HETE Alert 3274 optical observation
  12. Activivty of SGR 1806-20
  13. GRB 040511, very fast decay?
  14. GRB 030324: Detection and Color of Host Galaxy
  15. GRB 040511: NIR observations with REM
  16. GRB040511: Candidate optical/NIR afterglow
  17. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  18. GRB 040511: Second Epoch Optical Observations
  19. GRB 040511: Optical observations
  20. GRB 040511: Optical Observations
  21. GRB040511: Optical Observations
  22. GRB040511: Optical Observations
  23. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  24. GRB 040423 (=H3175): A Long GRB Localized by HETE
  25. GRB040422 : I-band follow-up observation at Lulin Observatory
  26. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  27. GRB040422, BVRcIc field calibration
  28. GRB 040422,optical observation
  29. GRB 040422: a long GRB detected with INTEGRAL
  30. GRB 040403, deep optical observations
  31. MASTER: HETE Alert 3163, 3167 technical optical observation
  32. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  33. GRB 040403: Optical observations
  34. GRB 040403: a long GRB detected with INTEGRAL
  35. GRB040323: NIR Observations and Variable Object
  36. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  37. GRB 040323, a dark GRB ?
  38. GRB 040323: a long GRB detected with INTEGRAL
  39. GRB040223: Deep NIR NTT data re-analysis
  40. GRB 040223: XMM-Newton results
  41. GRB040223, improved XMM position
  42. GRB 031203, possible supernova
  43. MASTER: RXTE GRB040308 optical observation
  44. IBAS results on a burst from SGR1806-20
  45. INTEGRAL detection of activity from SGR1806-20
  46. RXTE GRB040229 optical observation: no candidate
  47. GRB 040228 Optical observations
  48. GRB040228 : KISO optical follow-up observation
  49. GRB 040223: Deep NIR NTT observations
  50. GRB 040223 : Optical observation (non-detection)
  51. XMM-Newton Images of GRB 040223
  52. GRB 040223, VLA observations
  53. GRB 040223: REM IJK Observations
  54. GRB 040223 XMM-Newton observation ...
  55. GRB 031203 XMM-Newton observation
  56. GRB 040223: further offline analysis
  57. GRB031111, optical observations
  58. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  59. GRB031203: Chandra Observations
  60. GRB040106: refined X-ray transient position
  61. SN 2003dh/GRB030329 late-time optical spectroscopy
  62. GRB 031220: Optical observations of Chandra X-ray sources
  63. XMM-Newton Images of GRB 040106
  64. GRB031220: observation at Univercity of Miyazaki
  65. XMM-Newton observation of GRB040106
  66. GRB 040106 : peak flux
  67. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  68. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  69. GRB031220: Palomar Observations
  70. GRB 031220 : Kyoto Optical Observation
  71. GRB 031220: Subaru observation
  72. GRB 031220: Optical observation at Tokyo Tech
  73. GRB 2974 follow-up observations
  74. GRB031203, improved XMM position
  75. GRB 021203: A Normal GRB viewed far off axis?
  76. XMM-Newton Observations of GRB031203: Preliminary Images
  77. GRB 031203: Variable Radio Source
  78. GRB 031203: Magellan spectrum of possible GRB host
  79. GRB 031203: Optical/IR Astrometry
  80. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  81. XMM-Newton Observation of GRB031203
  82. GRB031203: K' Photometry of the likely GRB host
  83. XMM-Newton Observation of GRB031203
  84. GRB 031203: IR NTTobservations do not confirm REM detection
  85. GRB031203 : Optical Observation of Lulin Observatory
  86. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  87. GRB 031203: Apparent Spectral Break
  88. GRB031203: Planned XMM-Newton observation II
  89. GRB 031203: IR REM Observations
  90. GRB031203: Optical Observations
  91. GRB 031203 XMM-Newton observation
  92. GRB031203: Planned XMM-Newton observation
  93. GRB 031203: further analysis of INTEGRAL data
  94. GRB 030329: Planned XMM-Newton Observation
  95. GRB 031111B (= H2925) : Kyoto Optical Observation
  96. IPN triangulation of GRB031114 (large error box)
  97. GRB 031111, optical observations
  98. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  99. GRB030929/SN2003jd association unlikely based on IPN localiztion
  100. IPN triangulation of GRB031027 (small error box)

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