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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

24683 results found.

  1. GRB 040730: a long GRB detected with INTEGRAL
  2. Ongoing activity of SGR 1806-20
  3. GRB040624: optical monitoring at TNG
  4. XRF 040701 - optical observations of the decaying Chandra source
  5. XRF040701: Second-Epoch Chandra Observations
  6. XRF040701: VLA Observations
  7. XRF040701: First-Epoch Chandra Observations
  8. GRB040624, optical observations
  9. GRB040706:observation at University of Miyazaki
  10. Optical Observations of GRB040624
  11. GRB 040624: optical observations at TNG and VLT
  12. MASTER: GRB 040624 optical observation after 0,48d
  13. GRB 040624, optical observations
  14. GRB 040624 - A long GRB detected with INTEGRAL
  15. GRB 030329: Rebrightening of hyperluminal ejecta.
  16. IPN Summary of SGR1806-20 Activity in 2004
  17. SGR 1806-20: no IR variability of the proposed counterparts
  18. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  19. SGR 1806-20, potential NIR counterpart
  20. GRB 040606: Optical observations
  21. MASTER: HETE Alert 3274 optical observation
  22. Activivty of SGR 1806-20
  23. GRB 040511, very fast decay?
  24. GRB 030324: Detection and Color of Host Galaxy
  25. GRB 040511: NIR observations with REM
  26. GRB040511: Candidate optical/NIR afterglow
  27. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  28. GRB 040511: Second Epoch Optical Observations
  29. GRB 040511: Optical observations
  30. GRB 040511: Optical Observations
  31. GRB040511: Optical Observations
  32. GRB040511: Optical Observations
  33. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  34. GRB 040423 (=H3175): A Long GRB Localized by HETE
  35. GRB040422 : I-band follow-up observation at Lulin Observatory
  36. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  37. GRB040422, BVRcIc field calibration
  38. GRB 040422,optical observation
  39. GRB 040422: a long GRB detected with INTEGRAL
  40. GRB 040403, deep optical observations
  41. MASTER: HETE Alert 3163, 3167 technical optical observation
  42. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  43. GRB 040403: Optical observations
  44. GRB 040403: a long GRB detected with INTEGRAL
  45. GRB040323: NIR Observations and Variable Object
  46. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  47. GRB 040323, a dark GRB ?
  48. GRB 040323: a long GRB detected with INTEGRAL
  49. GRB040223: Deep NIR NTT data re-analysis
  50. GRB 040223: XMM-Newton results
  51. GRB040223, improved XMM position
  52. GRB 031203, possible supernova
  53. MASTER: RXTE GRB040308 optical observation
  54. IBAS results on a burst from SGR1806-20
  55. INTEGRAL detection of activity from SGR1806-20
  56. RXTE GRB040229 optical observation: no candidate
  57. GRB 040228 Optical observations
  58. GRB040228 : KISO optical follow-up observation
  59. GRB 040223: Deep NIR NTT observations
  60. GRB 040223 : Optical observation (non-detection)
  61. XMM-Newton Images of GRB 040223
  62. GRB 040223, VLA observations
  63. GRB 040223: REM IJK Observations
  64. GRB 040223 XMM-Newton observation ...
  65. GRB 031203 XMM-Newton observation
  66. GRB 040223: further offline analysis
  67. GRB031111, optical observations
  68. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  69. GRB031203: Chandra Observations
  70. GRB040106: refined X-ray transient position
  71. SN 2003dh/GRB030329 late-time optical spectroscopy
  72. GRB 031220: Optical observations of Chandra X-ray sources
  73. XMM-Newton Images of GRB 040106
  74. GRB031220: observation at Univercity of Miyazaki
  75. XMM-Newton observation of GRB040106
  76. GRB 040106 : peak flux
  77. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  78. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  79. GRB031220: Palomar Observations
  80. GRB 031220 : Kyoto Optical Observation
  81. GRB 031220: Subaru observation
  82. GRB 031220: Optical observation at Tokyo Tech
  83. GRB 2974 follow-up observations
  84. GRB031203, improved XMM position
  85. GRB 021203: A Normal GRB viewed far off axis?
  86. XMM-Newton Observations of GRB031203: Preliminary Images
  87. GRB 031203: Variable Radio Source
  88. GRB 031203: Magellan spectrum of possible GRB host
  89. GRB 031203: Optical/IR Astrometry
  90. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  91. XMM-Newton Observation of GRB031203
  92. GRB031203: K' Photometry of the likely GRB host
  93. XMM-Newton Observation of GRB031203
  94. GRB 031203: IR NTTobservations do not confirm REM detection
  95. GRB031203 : Optical Observation of Lulin Observatory
  96. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  97. GRB 031203: Apparent Spectral Break
  98. GRB031203: Planned XMM-Newton observation II
  99. GRB 031203: IR REM Observations
  100. GRB031203: Optical Observations

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