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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"

45610 results found.

  1. GRB 030329: Radio Observations
  2. GRB 030329, optical spectroscopy
  3. GRB 030329: still bright
  4. GRB 030329: Optical pre-Imaging
  5. GRB 030329: visual observations
  6. GRB 030329: Upper limit from 5.6 hours before trigger
  7. GRB030328: R optical observation
  8. GRB030328: X-ray Afterglow Observed with Chandra
  9. GRB 030323: Gemini South VRI obsevations.
  10. GRB030329: Optical observations
  11. GRB 030329, R-band observations, supplement
  12. GRB030329 optical observations
  13. GRB030329:optical observations by MASTER
  14. GRB 030329: optical observations
  15. GRB 030329, R-band observations
  16. GRB 030329: OT B and R photometry, decline rate
  17. GRB030329: Upper limits from recent and historical observations.
  18. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  19. RXTE detection of GRB 030329 afterglow
  20. GRB 030329: Optical Afterglow Observations
  21. GRB 030329: precise position from Kyoto images
  22. GRB 030328 Optical Observations
  23. GRB030328: Decay index
  24. GRB 030328: Optical observations
  25. GRB 030328: optical observations
  26. GRB 030329: Optical afterglow fading
  27. GRB 030329 follow-up
  28. GRB 030329: Optical afterglow candidate
  29. GRB 030329: OT candidate
  30. GRB 030329: Optical afterglow candidate
  31. GRB 030328: OT photometry
  32. GRB030328: optical spectroscopy at TNG
  33. GRB030328: optical photometry at the TNG
  34. VLT spectra of GRB 030328
  35. GRB 030328, optical spectroscopy
  36. GRB 030328, optical observations
  37. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  38. GRB 030328: Optical observations
  39. Re: GRB 030328: Finding chart
  40. GRB 030328: Finding chart
  41. GRB 030328: Optical afterglow candidate
  42. GRB030323 optical observations
  43. GRB030324 optical observation
  44. GRB030131, BVRcIc field photometry
  45. Possible GRB030323 localized by INTEGRAL
  46. IPN triangulation of GRB030325 (final analysis)
  47. GRB030323: Detection on 2003/03/24
  48. IPN triangulation of GRB030326 (single small error box)
  49. GRB 030323: SARA Optical Observations
  50. IPN triangulation of GRB030325 (single small error box)
  51. GRB030324, optical observations
  52. GRB030324, optical observations
  53. IPN triangulation of GRB030325 (two small error boxes)
  54. GRB 030324: TAROT optical observations
  55. GRB030323: V, R, I photometry
  56. GRB 030324 (HETE #2641): Optical observations
  57. GRB030324, Optical Observations
  58. GRB030323: Upper limits from recent and historical observations.
  59. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  60. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  61. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  62. VLT/FORS2 spectra of GRB 030323
  63. GRB030323, ROTSE-III detection of possible optical counterpart
  64. GRB030323, optical observations
  65. GRB030324, BVRcIc field photometry
  66. GRB030323, possible optical counterpart
  67. GRB030323, BVRcIc field calibration
  68. GRB 030324 optical observations
  69. GRB 030320: Optical Observations
  70. GRB 030324, optical observations
  71. IPN triangulation of GRB030320B (annulus)
  72. IPN triangulation of GRB030320 (small error box)
  73. IPN triangulation of GRB030320
  74. Possible GRB 030320 localized by INTEGRAL
  75. GRB030226, addendum to GCN 1892
  76. IPN upper limit to a GRB associated with SN2003L
  77. IPN triangulation of GRB030317 (annulus)
  78. IPN triangulation of GRB030307 (annulus)
  79. GRB 030227: Optical limit at RIKEN
  80. GRB 030226 Optical observations
  81. IPN triangulation of GRB030306 (single small error box - REVISED)
  82. GRB030226: Optical observations at Asiago
  83. IPN triangulation of GRB030306 (single small error box)
  84. IPN triangulation of GRB030306 (two small error boxes)
  85. IPN triangulation of GRB030306 (intense; annulus only so far)
  86. GRB 030226: Optical observations
  87. GRB030226: Analysis of Chandra data
  88. IPN triangulation of GRB030304 (annulus)
  89. GRB 030227: Optical observations
  90. GRB030226, BVRc observations
  91. Chandra detection of the X-ray afterglow of GRB 030226
  92. GRB 030226, further optical/NIR imaging
  93. GRB030227, optical observations
  94. GRB 030226: Ic Observations
  95. GRB030227: Kiso optical upper limit
  96. IPN triangulation of GRB030301 (annulus)
  97. IPN triangulation of GRB030228 (annulus)
  98. GRB030227, BVRcIc field photometry
  99. GRB030226, BVRcIc field calibration
  100. GRB 030227 optical afterglow

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