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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.

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

24662 results found.

  1. Confirmation of IPN position for GRB001204
  2. IPN triangulation of GRB001204 (short/hard)
  3. GRB001120, optical observations
  4. WSRT 4.8 GHz observations of GRB001109
  5. IPN triangulation of GRB001120
  6. GRB 001109: deep JHK upper limits
  7. GRB 001109 X-ray afterglow with BeppoSAX
  8. CORRECTION to XMM-Newton observation of GRB001025
  9. GRB001109, Radio observations
  10. GRB001105 BVRI field photometry correction
  11. GRB001105, BVRI field photometry
  12. IPN TRIANGULATION OF GRB001105
  13. GRB 001025B, Optical obervations
  14. GRB 991208: HST Imaging of the Host Galaxy
  15. GRB 001025B, I-band observations
  16. XMM-Newton observation of GRB001025
  17. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  18. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  19. GRB001007: Optical observations
  20. ASM Localization of GRB 001025
  21. GRB001007, Radio observations
  22. GRB 001018, Possible Radio Afterglow
  23. GRB001018, Gamma Ray Observations
  24. IPN TRIANGULATION OF GRB001019
  25. IPN TRIANGULATION OF GRB001018
  26. IPN TRIANGULATION OF GRB 001017
  27. V,R,I band observations of GRB000926
  28. HETE positions added to GCN
  29. GRB000926 - Amateur Optical Observations
  30. CONCAM null result on GRB001005
  31. IPN triangulation of GRB001005
  32. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  33. GRB000926 - Optical observations
  34. GRB000926 - Optical observations
  35. GRB 000926, Optical Decay
  36. GRB000911: VLT infrared observation
  37. GRB 000926, Optical Observations
  38. GRB000926 K'-band Observation
  39. J and K band observations of GRB 000926
  40. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  41. CONCAM crude optical limits before and after GRB000926
  42. GRB 000926: Preliminary R-band Lightcurve
  43. Spectroscopic Redshift of GRB 000926
  44. GRB 000926: Optical candidate
  45. Optical candidate for GRB000926
  46. GRB 000911, BVRI field photometry
  47. GRB000911, Radio and Optical observations
  48. GRB000911: Optical observations
  49. GRB000830, BVRI field photometry
  50. GRB000210, Optical observations
  51. "Snapshot" afterglow IDs and GRB 000830
  52. GRB000730, Gamma Ray Observations
  53. GRB000812, Radio observations
  54. GRB000801, Gamma Ray Observations
  55. GRB000801, VLT-Antu R-band observations
  56. GRB 991208 Host Galaxy Imaging
  57. IPN localization of GRB000730B
  58. GRB 990510: Possible detection of a host galaxy
  59. GRB 990510 Host Galaxy Discovery
  60. IPN localization of GRB000727
  61. GRB 990712: Late time HST/STIS Observations
  62. GRB 991216, HST/STIS observations
  63. GRB000620, Radio Observations
  64. GRB000630, optical observations
  65. GRB000630, Revised BVRI Field Photometry
  66. GRB000630, Optical Observations
  67. GRB000630, optical observations
  68. GRB000630, optical observations
  69. GRB000630, BVRI Field Photometry
  70. GRB000630, optical observations
  71. GRB000630: Optical observations
  72. GRB000630, Radio Observations
  73. possible optical counterpart of GRB 000630
  74. GRB 000620, optical observations
  75. GRB000418, HST/STIS Observations
  76. GRB990123: Late-time HST/STIS observations of the host
  77. GRB000620, optical observations
  78. GRB000615: H-band observations
  79. GRB990308, HST/STIS observations of the host galaxy
  80. GRB000620 - Optical observations
  81. GRB000620 Optical observations
  82. GRB000620: BeppoSAX WFC and GRBM detection
  83. GRB000607, optical observations
  84. GRB 000615: NIR further observations
  85. GRB990123, HST/STIS observations of the host galaxy
  86. GRB000616 optical observations
  87. GRB 000615, near-infrared observations
  88. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  89. GRB000615, further R-band photometry
  90. GRB 000615: NIR observations
  91. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  92. GRB000615, R-band photometry
  93. The Hosts of GRB 980703 and GRB 971214
  94. GRB 000301C: Further Late-Time HST/STIS observations
  95. GRB000528: follow-up X-ray measurements and update of IPN annulus
  96. GRB980519, HST/STIS observations of the host galaxy
  97. GRB000604 optical non-detection
  98. GRB000604 - Optical observations
  99. GRB000604, optical observations
  100. GRB000528, optical observations at ESO

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