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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"
  1. IPN triangulation of GRB030605 (annulus)
  2. GRB 030528: tentative NIR counterpart
  3. GRB 030528, radio observations
  4. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  5. GRB030329, further radio observations at GMRT
  6. GRB030528, BVRI field photometry
  7. IPN triangulation of GRB030601 (annulus)
  8. GRB030329, SPM optical observations
  9. GRB030528: Chandra TOO Planned
  10. GRB 030519B: optical observations.
  11. MASTER: optical observation GRB030601
  12. GRB030528(=H2724): Revised SXC Localization
  13. GRB 030329: optical observations
  14. GRB 030329/SN 2003dh: Jitter Episode
  15. GRB 030528, Teramo optical observation
  16. GRB 030528 Bisei optical observation
  17. GRB030528 (H2724): A long GRB localized by HETE
  18. GRB 030329: Correction to GCN 2254
  19. GRB 030329: Optical Observations
  20. GRB 030528: Optical observations at RIKEN
  21. GRB 030528 (=H2724) Kyoto optical observation
  22. IPN triangulation of GRB030523B (annulus)
  23. GRB 030416: Optical Observations
  24. GRB 030329: Planned XMM-Newton Observation
  25. IPN triangulation of GRB030523 (annulus)
  26. GRB 030329: optical photometry at various french observatories
  27. GRB 030329: optical photometry at Belesta observatory (France)
  28. GRB030329, Optical observations
  29. GRB 030329/SN 2003dh: Possible increase in brightness
  30. GRB 030329: HST ACS Observations of the Host
  31. GRB 030329 Optical Observations
  32. GRB030329: XMM-Newton observation
  33. GRB 021004: HST observations
  34. GRB030324: Further Observations of the Candidate Optical Afterglow
  35. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  36. IPN triangulation of GRB030519B=H2716 (small error box)
  37. GRB 030418: Second Epoch Optical Observations with Magellan
  38. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  39. IPN triangulation of GRB030519 (annulus)
  40. IPN triangulation of GRB030518C (annulus)
  41. IPN triangulation of GRB030518B (annulus)
  42. IPN triangulation of GRB030518A (annulus)
  43. IPN triangulation of GRB030514 (annulus)
  44. HETE GRB030329, correction to Rc Observations in Loiano
  45. IPN triangulation of GRB030513 (annulus)
  46. IPN triangulation of GRB030509B (annulus)
  47. GRB 030329: Optical limit (contemporaneous imaging)
  48. GRB 030501: final TAROT limits
  49. IPN triangulation of GRB030509 (small errror box)
  50. IPN triangulation of GRB030509 - correction
  51. IPN triangulation of GRB030509 (single error box)
  52. GRB030329: RTT150 optical observations
  53. GRB030329, BVRI photometry
  54. GRB030429, refiend optical brightness
  55. GRB 030329: Optical limit (contemporaneous photography)
  56. GRB030418, BVRcIc field photometry
  57. GRB 030429: Redshift of neighbor galaxy
  58. GRB030429, BVRcIc field photometry
  59. GRB030429: RTT150 optical obs., correction to GCN 2208
  60. GRB 030329: High-Resolution Spectroscopy of the Host
  61. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  62. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  63. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  64. GRB030429: RTT150 optical observations, a possible host galaxy
  65. IPN triangulation of GRB030506 (annulus)
  66. IPN triangulation of GRB030505B (large error box)
  67. IPN triangulation of GRB030505A (annulus)
  68. GRB030329: RTT150 optical observations and upper limit for a host
  69. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  70. GRB030501, optical observation
  71. GRB030501 observation report
  72. GRB030501C triangulation (annulus)
  73. GRB030501 triangulation (correction to GCN 2194)
  74. GRB030329: RTT150 optical observations and upper limit for a host
  75. GRB 030429: Radio Observations
  76. GRB 030429: redshift from VLT spectroscopy
  77. GRB 030429: IR photometry with IRSF/SIRIUS
  78. GRB030501B triangulation (single error box)
  79. GRB 030329 Optical Observations
  80. GRB030328, optical observation
  81. GRB 030329, BVRI photometry
  82. GRB030429: Optical Observations
  83. GRB030501: TAROT candidate afterglow present in archival images
  84. GRB 030501: TAROT possible candidate counterpart
  85. IPN triangulation of GRB030501 (IBIS event; annulus)
  86. IPN triangulation of GRB030501B (annulus)
  87. GRB 030429: confirmation of afterglow candidate
  88. GRB030429, possible optical counterpart
  89. GRB030501 localized by INTEGRAL
  90. GRB030425: CrAO optical observation
  91. IPN triangulation of GRB030429 (annulus)
  92. IPN triangulation of GRB030428 (two large error boxes)
  93. GRB 030329 Oprical observations in Rozhen observatory
  94. GRB 030429: ROTSE-III observations
  95. GRB 030324: Radio Observations
  96. GRB030329 observed as a sudden ionospheric disturbance (SID)
  97. IPN triangulation of GRB030426 (annulus)
  98. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  99. IPN triangulation of GRB030425 (single error box)
  100. GRB030329, SPM optical observations (Correction)

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