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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"

15251 results found.

  1. SGR1806-20: A Second, Intense Burst Localized by HETE
  2. SGR1806-20: Localization by HETE
  3. GRB010518: a faint BeppoSAX detection
  4. X-ray precursors to the large flare from SGR 1900+14
  5. SGR 1900+14 : RXTE observations
  6. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  7. SGR 1900+14: Correction to GCN 1049
  8. Millimeter observation of SGR 1900+14
  9. Chandra Observations of SGR 1900+14
  10. Possible precursor to the SGR1900+14 giant burst
  11. IPN Triangulation of the Giant Flare from SGR1900+14
  12. GRB010412: Optical observations
  13. GRB010412: BeppoSAX GRBM and WFC observations
  14. REVISED LOCATION OF GRB010326A
  15. GRB010324, field photometry
  16. Further Optical Observations of GRB 010324
  17. GRB010326B: Localization by HETE (2nd GRB for this date)
  18. GRB010326: Refined Localization by HETE
  19. GRB010326: Localization by HETE
  20. IPN TRIANGULATION OF GRB010324
  21. Support extension to the BeppoSAX mission
  22. GRB 010222 - HEGRA GeV/TeV Observations
  23. GRB010220 optical obsercations
  24. GRB 010222: High-Resolution Keck Spectroscopy
  25. GRB 010214, I-band data
  26. Sub-millimeter Excess/GRB 010222
  27. GRB 010222
  28. GRB010222 further R-band photometry
  29. GRB 010222: Keck Spectroscopy
  30. GRB010222 further R-band photometry
  31. GRB 010220: Near-IR Observations
  32. GRB010214 follow-up from Hanle
  33. GRB 010222: Near-IR Observations
  34. GRB 010222, Decay Slope Confirmed
  35. GRB010222: Another absorption line system
  36. GRB 010214, Optical Observations
  37. GRB010222, radio observations
  38. GRB010222, optical observations
  39. GRB 010220, simultaneous optical observations
  40. GRB010220: BeppoSAX WFC and GRBM preliminary data
  41. GRB010214, optical observations
  42. GRB010214: BeppoSAX WFC and GRBM preliminary data
  43. GRB 010214: X-Ray afterglow
  44. GRB 010214, Optical Observations
  45. GRB 010214 optical observation
  46. GRB010213, Radio Observations
  47. J-Band Observation of GRB 010214.
  48. GRB010213 detected by HETE
  49. HETE Status
  50. IPN/RXTE TRIANGULATION OF GRB010126
  51. GRB010126: CONCAM crude optical limits during GRB
  52. GRB010126, TNG R-band observations
  53. GRB010126 Optical Observations
  54. GRB010126 optical observations
  55. IPN/RXTE TRIANGULATION OF GRB010126
  56. GRB 010119, optical observations
  57. Optical Observations of GRB 001018 at Keck
  58. Optical observations of GRB 001018 with JCAM
  59. H band observation of GRB 001212
  60. GRB001120: Gunn-i observations
  61. GRB001120, optical observations
  62. WSRT 4.8 GHz observations of GRB001109
  63. Optical/NIR observations of GRB001109
  64. GRB 001109: deep JHK upper limits
  65. GRB 001109 X-ray afterglow with BeppoSAX
  66. GRB001109, R-band optical observations
  67. GRB 991208: HST Imaging of the Host Galaxy
  68. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  69. ASM Localization of GRB 001025
  70. GRB 000926: Improved Absorber Redshift
  71. GRB 001007, BVR-band observations
  72. GRB000926 - Amateur Optical Observations
  73. CONCAM null result on GRB001005
  74. Public availability of BeppoSAX data of GRB000926
  75. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  76. GRB000926 - Optical observations
  77. GRB 000926, Optical Observations
  78. GRB000911: optical VLT observations
  79. GRB000926 K'-band Observation
  80. GRB 000926, optical observation by Oksanen (vsnet-grb)
  81. Spectroscopic Redshift of GRB 000926
  82. GRB000926, radio observations
  83. GRB 000926: Optical candidate
  84. Optical candidate for GRB000926
  85. GRB 000830: Optical observations
  86. GRB000801 & GRB000730, Gamma Ray Observations
  87. GRB 000727, optical observations
  88. IPN localization of GRB000727
  89. GRB 990712: Late time HST/STIS Observations
  90. GRB000630, optical observations
  91. GRB000630, optical observations
  92. GRB000630, optical observations
  93. GRB000630: Optical observations
  94. GRB000630, Radio Observations
  95. GRB000418, HST/STIS Observations
  96. GRB990123: Late-time HST/STIS observations of the host
  97. GRB000620, optical observations
  98. GRB000615: H-band observations
  99. GRB000620: BeppoSAX WFC and GRBM detection
  100. GRB000607, optical observations

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