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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"

45715 results found.

  1. GRB 030329, optical spectroscopy
  2. GRB 030329: still bright
  3. GRB 030329: Optical pre-Imaging
  4. GRB 030329: visual observations
  5. GRB 030329: Upper limit from 5.6 hours before trigger
  6. GRB030328: R optical observation
  7. GRB030328: X-ray Afterglow Observed with Chandra
  8. GRB 030323: Gemini South VRI obsevations.
  9. GRB030329: Optical observations
  10. GRB 030329, R-band observations, supplement
  11. GRB030329 optical observations
  12. GRB030329:optical observations by MASTER
  13. GRB 030329: optical observations
  14. GRB 030329, R-band observations
  15. GRB 030329: OT B and R photometry, decline rate
  16. GRB030329: Upper limits from recent and historical observations.
  17. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  18. RXTE detection of GRB 030329 afterglow
  19. GRB 030329: Optical Afterglow Observations
  20. GRB 030329: precise position from Kyoto images
  21. GRB 030328 Optical Observations
  22. GRB030328: Decay index
  23. GRB 030328: Optical observations
  24. GRB 030328: optical observations
  25. GRB 030329: Optical afterglow fading
  26. GRB 030329 follow-up
  27. GRB 030329: Optical afterglow candidate
  28. GRB 030329: OT candidate
  29. GRB 030329: Optical afterglow candidate
  30. GRB 030328: OT photometry
  31. GRB030328: optical spectroscopy at TNG
  32. GRB030328: optical photometry at the TNG
  33. VLT spectra of GRB 030328
  34. GRB 030328, optical spectroscopy
  35. GRB 030328, optical observations
  36. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  37. GRB 030328: Optical observations
  38. Re: GRB 030328: Finding chart
  39. GRB 030328: Finding chart
  40. GRB 030328: Optical afterglow candidate
  41. GRB030323 optical observations
  42. GRB030324 optical observation
  43. GRB030131, BVRcIc field photometry
  44. Possible GRB030323 localized by INTEGRAL
  45. IPN triangulation of GRB030325 (final analysis)
  46. GRB030323: Detection on 2003/03/24
  47. IPN triangulation of GRB030326 (single small error box)
  48. GRB 030323: SARA Optical Observations
  49. IPN triangulation of GRB030325 (single small error box)
  50. GRB030324, optical observations
  51. GRB030324, optical observations
  52. IPN triangulation of GRB030325 (two small error boxes)
  53. GRB 030324: TAROT optical observations
  54. GRB030323: V, R, I photometry
  55. GRB 030324 (HETE #2641): Optical observations
  56. GRB030324, Optical Observations
  57. GRB030323: Upper limits from recent and historical observations.
  58. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  59. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  60. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  61. VLT/FORS2 spectra of GRB 030323
  62. GRB030323, ROTSE-III detection of possible optical counterpart
  63. GRB030323, optical observations
  64. GRB030324, BVRcIc field photometry
  65. GRB030323, possible optical counterpart
  66. GRB030323, BVRcIc field calibration
  67. GRB 030324 optical observations
  68. GRB 030320: Optical Observations
  69. GRB 030324, optical observations
  70. IPN triangulation of GRB030320B (annulus)
  71. IPN triangulation of GRB030320 (small error box)
  72. IPN triangulation of GRB030320
  73. Possible GRB 030320 localized by INTEGRAL
  74. GRB030226, addendum to GCN 1892
  75. IPN upper limit to a GRB associated with SN2003L
  76. IPN triangulation of GRB030317 (annulus)
  77. IPN triangulation of GRB030307 (annulus)
  78. GRB 030227: Optical limit at RIKEN
  79. GRB 030226 Optical observations
  80. IPN triangulation of GRB030306 (single small error box - REVISED)
  81. GRB030226: Optical observations at Asiago
  82. IPN triangulation of GRB030306 (single small error box)
  83. IPN triangulation of GRB030306 (two small error boxes)
  84. IPN triangulation of GRB030306 (intense; annulus only so far)
  85. GRB 030226: Optical observations
  86. GRB030226: Analysis of Chandra data
  87. IPN triangulation of GRB030304 (annulus)
  88. GRB 030227: Optical observations
  89. GRB030226, BVRc observations
  90. Chandra detection of the X-ray afterglow of GRB 030226
  91. GRB 030226, further optical/NIR imaging
  92. GRB030227, optical observations
  93. GRB 030226: Ic Observations
  94. GRB030227: Kiso optical upper limit
  95. IPN triangulation of GRB030301 (annulus)
  96. IPN triangulation of GRB030228 (annulus)
  97. GRB030227, BVRcIc field photometry
  98. GRB030226, BVRcIc field calibration
  99. GRB 030227 optical afterglow
  100. 030302: NOT A GRB

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