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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"

37095 results found.

  1. GRB010921, negative optical observations
  2. GRB010921 field photometry
  3. GRB010921 Optical Observations
  4. GRB 010921 DPOSS Images Available
  5. IPN triangulation of GRB010921 (=H1761)
  6. H1761: A Bright GRB Detected by HETE
  7. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  8. HETE Trigger #1760 (GRB 010920B?): a new optical source
  9. HETE Trigger #1759 (GRB 010920?) optical observations
  10. GRB001109, Host Galaxy Astrometry
  11. GRB000926, Host Galaxy Observations
  12. GRB001109, Host Galaxy Spectroscopic Observations
  13. Probable SGR or Short Duration GRB Detected by HETE
  14. GRB000926 Host Galaxy Observations
  15. GRB 010222: HST observations -- host galaxy and late-time decay
  16. BeppoSAX/GRBM detection of GRB 010801
  17. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  18. GRB 010222 - WHT BVRI images
  19. GRB 010629 Optical Observations
  20. GRB010629: Optical Observations
  21. SGR1900+14: High Fluence Burst Localized by HETE
  22. GRB010629, optical observations
  23. IPN triangulation of GRB010629
  24. GRB010629: A Burst Localized by HETE
  25. SGR1900+14: A Burst Localized by HETE
  26. Possible burst from SGR1806-20
  27. IPN detection of SGR1900+14
  28. SGR1806-20: A Second, Intense Burst Localized by HETE
  29. GRB 00630: Host Galaxy
  30. IPN triangulation of GRB010613
  31. IPN triangulation of GRB010612
  32. HETE Fully-Automated GCN Notices
  33. GRB000301C: Late-time HST/STIS observation
  34. GRB010518: a faint BeppoSAX detection
  35. GRB000418: HST/STIS Second-epoch Observations
  36. GRB010427, Gamma Ray Observations
  37. SGR 1900+14 : RXTE observations
  38. SGR1900+14
  39. GRB 010222 /corrections to VBT data
  40. SGR 1900+14, Chandra observations
  41. Possible precursor to the SGR1900+14 giant burst
  42. IPN Triangulation of the Giant Flare from SGR1900+14
  43. GRB010412, field photometry
  44. GRB 010326b Optical Observations
  45. GRB010412: Optical observations
  46. GRB010412: Optical observations
  47. IPN Triangulation of GRB010412
  48. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  49. BeppoSAX GRB ALERT: GRB010412
  50. GRB Observation Report
  51. GRB010324, revised field photometry
  52. REVISED LOCATION OF GRB010326A
  53. GRB 980326: Late-time HST/STIS observations
  54. GRB010324, field photometry
  55. GRB010326B, field photometry
  56. GRB010326, field photometry
  57. GRB010220, field photometry
  58. Further Optical Observations of GRB 010324
  59. GRB 010326A: Further optical observations
  60. GRB010324: BeppoSAX/GRBM data
  61. GRB 010326B: Optical observations
  62. GRB010324, optical observations
  63. GRB010326B: Localization by HETE (2nd GRB for this date)
  64. GRB 010326: Optical observations
  65. GRB 010326 optical observations
  66. GRB010326: Refined Localization by HETE
  67. GRB010326: Localization by HETE
  68. Duration, ECT, peak flux and fluence of GRB010324
  69. Optical Observations of GRB 010324
  70. IPN TRIANGULATION OF GRB010324
  71. GRB990705, VLT-FORS1 observations of the host galaxy
  72. GRB010222, late-time optical observation
  73. Support extension to the BeppoSAX mission
  74. GRB 010222 - HEGRA GeV/TeV Observations
  75. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  76. GRB010222: Chandra X-ray Observatory Observation
  77. GRB010222: Sub-millimeter vanishing act
  78. GRB 010222, Optical Observations
  79. GRB 010222: High-Resolution Keck Spectroscopy
  80. GRB 010214, I-band data
  81. Sub-millimeter Excess/GRB 010222
  82. GRB 010222
  83. GRB 010222 HST/Chandra TOO
  84. GRB 010222
  85. GRB010222 further R-band photometry
  86. GRB010222: R-band data
  87. GRB010222 Optical observations
  88. GRB 010222: Keck Spectroscopy
  89. GRB010214, field photometry
  90. GRB010222, field photometry
  91. GRB010222 further R-band photometry
  92. GRB010222, possible increase of optical decay slope
  93. GRB 010222 Kyoto optical observation
  94. GRB010222: fading behavior
  95. GRB 010222 BV optical observations
  96. GRB010220, Optical Observations
  97. GRB 010220: Near-IR Observations
  98. GRB010214 follow-up from Hanle
  99. GRB 010222: Near-IR Observations
  100. GRB 010222: Optical Observations

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