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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"

24659 results found.

  1. WSRT 4.8 GHz observations of GRB001109
  2. IPN triangulation of GRB001120
  3. GRB 001109: deep JHK upper limits
  4. GRB 001109 X-ray afterglow with BeppoSAX
  5. CORRECTION to XMM-Newton observation of GRB001025
  6. GRB001109, Radio observations
  7. GRB001105 BVRI field photometry correction
  8. GRB001105, BVRI field photometry
  9. IPN TRIANGULATION OF GRB001105
  10. GRB 001025B, Optical obervations
  11. GRB 991208: HST Imaging of the Host Galaxy
  12. GRB 001025B, I-band observations
  13. XMM-Newton observation of GRB001025
  14. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  15. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  16. GRB001007: Optical observations
  17. ASM Localization of GRB 001025
  18. GRB001007, Radio observations
  19. GRB 001018, Possible Radio Afterglow
  20. GRB001018, Gamma Ray Observations
  21. IPN TRIANGULATION OF GRB001019
  22. IPN TRIANGULATION OF GRB001018
  23. IPN TRIANGULATION OF GRB 001017
  24. V,R,I band observations of GRB000926
  25. HETE positions added to GCN
  26. GRB000926 - Amateur Optical Observations
  27. CONCAM null result on GRB001005
  28. IPN triangulation of GRB001005
  29. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  30. GRB000926 - Optical observations
  31. GRB000926 - Optical observations
  32. GRB 000926, Optical Decay
  33. GRB000911: VLT infrared observation
  34. GRB 000926, Optical Observations
  35. GRB000926 K'-band Observation
  36. J and K band observations of GRB 000926
  37. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  38. CONCAM crude optical limits before and after GRB000926
  39. GRB 000926: Preliminary R-band Lightcurve
  40. Spectroscopic Redshift of GRB 000926
  41. GRB 000926: Optical candidate
  42. Optical candidate for GRB000926
  43. GRB 000911, BVRI field photometry
  44. GRB000911, Radio and Optical observations
  45. GRB000911: Optical observations
  46. GRB000830, BVRI field photometry
  47. GRB000210, Optical observations
  48. "Snapshot" afterglow IDs and GRB 000830
  49. GRB000730, Gamma Ray Observations
  50. GRB000812, Radio observations
  51. GRB000801, Gamma Ray Observations
  52. GRB000801, VLT-Antu R-band observations
  53. GRB 991208 Host Galaxy Imaging
  54. IPN localization of GRB000730B
  55. GRB 990510: Possible detection of a host galaxy
  56. GRB 990510 Host Galaxy Discovery
  57. IPN localization of GRB000727
  58. GRB 990712: Late time HST/STIS Observations
  59. GRB 991216, HST/STIS observations
  60. GRB000620, Radio Observations
  61. GRB000630, optical observations
  62. GRB000630, Revised BVRI Field Photometry
  63. GRB000630, Optical Observations
  64. GRB000630, optical observations
  65. GRB000630, optical observations
  66. GRB000630, BVRI Field Photometry
  67. GRB000630, optical observations
  68. GRB000630: Optical observations
  69. GRB000630, Radio Observations
  70. possible optical counterpart of GRB 000630
  71. GRB 000620, optical observations
  72. GRB000418, HST/STIS Observations
  73. GRB990123: Late-time HST/STIS observations of the host
  74. GRB000620, optical observations
  75. GRB000615: H-band observations
  76. GRB990308, HST/STIS observations of the host galaxy
  77. GRB000620 - Optical observations
  78. GRB000620 Optical observations
  79. GRB000620: BeppoSAX WFC and GRBM detection
  80. GRB000607, optical observations
  81. GRB 000615: NIR further observations
  82. GRB990123, HST/STIS observations of the host galaxy
  83. GRB000616 optical observations
  84. GRB 000615, near-infrared observations
  85. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  86. GRB000615, further R-band photometry
  87. GRB 000615: NIR observations
  88. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  89. GRB000615, R-band photometry
  90. The Hosts of GRB 980703 and GRB 971214
  91. GRB 000301C: Further Late-Time HST/STIS observations
  92. GRB000528: follow-up X-ray measurements and update of IPN annulus
  93. GRB980519, HST/STIS observations of the host galaxy
  94. GRB000604 optical non-detection
  95. GRB000604 - Optical observations
  96. GRB000604, optical observations
  97. GRB000528, optical observations at ESO
  98. GRB 000604 optical observations
  99. GRB 000418: Detection of the Host Galaxy
  100. GRB000604, optical observations, comparison with DPOSS

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