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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"

35956 results found.

  1. GRB 030329: SARA Optical Observations
  2. AAVSO V & R observations of GRB030329
  3. IPN triangulation of GRB030331 (annulus)
  4. GRB 030329: optical observations
  5. IPN triangulation of GRB030329b (large error box)
  6. GRB 030329: beginning of the new fading phase in optical band
  7. GRB 030329, optical spectroscopy
  8. GRB 030329: fading X-ray afterglow with RXTE
  9. GRB 030329: optical photometry
  10. Photometry of GRB030329 - Constant OT Magnitude
  11. GRB 030329, R-band observations
  12. GRB 030329, R-band light curve
  13. GRB 030329: further optical observations
  14. GRB030329 - OT brightens
  15. GRB 030329: OT observations at Kanazawa
  16. GRB030329 15 GHz radio observation
  17. GRB 030329 RBO V Optical Observations
  18. GRB 030329, optical photometry
  19. GRB030329: Near Infrared Observations
  20. 030331 NOT A GRB
  21. INTEGRAL GRB 030331
  22. GRB 030324: Optical and NIR Observations
  23. GRB 030328, optical photometry
  24. GRB030329: R band light curve by MASTER
  25. GRB030329 - Light curve flattening
  26. GRB 030329: SARA Optical Observations
  27. GRB 030324, optical search
  28. GRB030329 - near contemporaneous optical limits from CONCAM
  29. GRB 030329, optical observations
  30. GRB 030329: Light curve observed during the change of its slope.
  31. GRB030329, BVRcIc field photometry
  32. GRB030329, SPM optical observations
  33. GRB 030329: Optical Decay
  34. Redshift of GRB 030329
  35. GRB030329: ROTSE network observes steepening of decay curve
  36. GRB 030329, optical photometry
  37. GRB 030329: Optical decay and synthesis
  38. GRB 030329: Radio Observations
  39. GRB 030329, optical spectroscopy
  40. GRB 030329: still bright
  41. GRB 030329: Optical pre-Imaging
  42. GRB 030329: visual observations
  43. GRB 030329: Upper limit from 5.6 hours before trigger
  44. GRB030328: R optical observation
  45. GRB 030323: Gemini South VRI obsevations.
  46. GRB030329: Optical observations
  47. GRB 030329, R-band observations, supplement
  48. GRB030329:optical observations by MASTER
  49. GRB 030329: optical observations
  50. GRB 030329, R-band observations
  51. GRB 030329: OT B and R photometry, decline rate
  52. GRB030329: Upper limits from recent and historical observations.
  53. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  54. RXTE detection of GRB 030329 afterglow
  55. GRB 030329: Optical Afterglow Observations
  56. GRB 030329: precise position from Kyoto images
  57. GRB 030328 Optical Observations
  58. GRB 030328: Optical observations
  59. GRB 030328: optical observations
  60. GRB 030329: Optical afterglow fading
  61. GRB 030329 follow-up
  62. GRB 030329: Optical afterglow candidate
  63. GRB 030329: OT candidate
  64. GRB 030329: Optical afterglow candidate
  65. GRB 030328: OT photometry
  66. VLT spectra of GRB 030328
  67. GRB 030328, optical spectroscopy
  68. GRB 030328, optical observations
  69. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  70. GRB 030328: Optical observations
  71. Re: GRB 030328: Finding chart
  72. GRB 030328: Finding chart
  73. GRB 030328: Optical afterglow candidate
  74. GRB030131, BVRcIc field photometry
  75. Possible GRB030323 localized by INTEGRAL
  76. IPN triangulation of GRB030325 (final analysis)
  77. IPN triangulation of GRB030326 (single small error box)
  78. GRB 030323: SARA Optical Observations
  79. IPN triangulation of GRB030325 (single small error box)
  80. GRB030324, optical observations
  81. IPN triangulation of GRB030325 (two small error boxes)
  82. GRB 030324: TAROT optical observations
  83. GRB 030324 (HETE #2641): Optical observations
  84. GRB030324, Optical Observations
  85. GRB030323: Upper limits from recent and historical observations.
  86. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  87. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  88. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  89. VLT/FORS2 spectra of GRB 030323
  90. GRB030323, ROTSE-III detection of possible optical counterpart
  91. GRB030323, optical observations
  92. GRB030324, BVRcIc field photometry
  93. GRB030323, possible optical counterpart
  94. GRB030323, BVRcIc field calibration
  95. GRB 030324 optical observations
  96. GRB 030320: Optical Observations
  97. GRB 030324, optical observations
  98. IPN triangulation of GRB030320B (annulus)
  99. IPN triangulation of GRB030320 (small error box)
  100. IPN triangulation of GRB030320

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