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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').
  1. IPN triangulation of GRB030513 (annulus)
  2. IPN triangulation of GRB030509B (annulus)
  3. GRB 030329: Optical limit (contemporaneous imaging)
  4. GRB 030501: final TAROT limits
  5. IPN triangulation of GRB030509 (small errror box)
  6. IPN triangulation of GRB030509 - correction
  7. IPN triangulation of GRB030509 (single error box)
  8. GRB030329: RTT150 optical observations
  9. GRB030329, BVRI photometry
  10. GRB030429, refiend optical brightness
  11. GRB 030329: Optical limit (contemporaneous photography)
  12. GRB030418, BVRcIc field photometry
  13. GRB 030429: Redshift of neighbor galaxy
  14. GRB030429, BVRcIc field photometry
  15. GRB030429: RTT150 optical obs., correction to GCN 2208
  16. GRB 030329: High-Resolution Spectroscopy of the Host
  17. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  18. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  19. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  20. GRB030429: RTT150 optical observations, a possible host galaxy
  21. IPN triangulation of GRB030506 (annulus)
  22. IPN triangulation of GRB030505B (large error box)
  23. IPN triangulation of GRB030505A (annulus)
  24. GRB030329: RTT150 optical observations and upper limit for a host
  25. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  26. GRB030501, optical observation
  27. GRB030501 observation report
  28. GRB030501C triangulation (annulus)
  29. GRB030501 triangulation (correction to GCN 2194)
  30. GRB030329: RTT150 optical observations and upper limit for a host
  31. GRB 030429: Radio Observations
  32. GRB 030429: redshift from VLT spectroscopy
  33. GRB 030429: IR photometry with IRSF/SIRIUS
  34. GRB030501B triangulation (single error box)
  35. GRB 030329 Optical Observations
  36. GRB030328, optical observation
  37. GRB 030329, BVRI photometry
  38. GRB030429: Optical Observations
  39. GRB030501: TAROT candidate afterglow present in archival images
  40. GRB 030501: TAROT possible candidate counterpart
  41. IPN triangulation of GRB030501 (IBIS event; annulus)
  42. IPN triangulation of GRB030501B (annulus)
  43. GRB 030429: confirmation of afterglow candidate
  44. GRB030429, possible optical counterpart
  45. GRB030501 localized by INTEGRAL
  46. GRB030425: CrAO optical observation
  47. IPN triangulation of GRB030429 (annulus)
  48. IPN triangulation of GRB030428 (two large error boxes)
  49. GRB 030329 Oprical observations in Rozhen observatory
  50. GRB 030429: ROTSE-III observations
  51. GRB 030324: Radio Observations
  52. GRB030329 observed as a sudden ionospheric disturbance (SID)
  53. IPN triangulation of GRB030426 (annulus)
  54. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  55. IPN triangulation of GRB030425 (single error box)
  56. GRB030329, SPM optical observations (Correction)
  57. GRB030329, SPM optical observations
  58. GRB 030329, the review of the sky area in plate archive (1950-1998)
  59. GRB 030329: Spectral Evolution of SN 2003dh
  60. Optical Observations of GRB 030418 with Magellan
  61. GRB 030329: optical spectropolarimetry at VLT
  62. IPN triangulation of GRB030422C (annulus)
  63. IPN triangulation of GRB030422B (annulus)
  64. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  65. GRB030329: optical polarization
  66. IPN triangulation of GRB030422 (two large error boxes)
  67. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  68. GRB030329, optical observation
  69. IPN triangulation of GRB030421 (annulus)
  70. MASTER:optical observations GRB030418
  71. MASTER:optical observations probable GRB030414
  72. GRB030329: 444 AAVSO Measurements
  73. IPN triangulation of GRB030419 (annulus)
  74. MASTER:optical observations GRB030416
  75. ROTSE-III prompt optical detections of GRB 030418
  76. GRB030418: Upper limits from recent and historical observations.
  77. GRB030418: Kiso near infrared observations
  78. GRB 030418: Optical afterglow
  79. GRB 030418: Finder for afterglow candidate
  80. GRB 030418: Optical afterglow candidate
  81. GRB 030329 OT position
  82. GRB030329: Optical Observations
  83. OT GRB 030329: early UBVRcIc spectral evolution
  84. GRB030329, UBVRI polarimetry, R-polarization
  85. GRB 030329: SARA Optical Observations
  86. OT GRB 030329: early spectrum
  87. GRB030329: VR Photometry at TNG
  88. GRB030324: Candidate Optical Afterglow (Erratum)
  89. GRB030324: Candidate Optical Afterglow
  90. IPN triangulation of GRB030414 (small error box)
  91. GRB 030413: Optical Observations
  92. GRB 030329 Rc observations
  93. IPN triangulation of GRB030413 (small error box)
  94. IPN triangulation of GRB030410 (annulus)
  95. Superluminal motion in GRB 030329 (Correction)
  96. Superluminal motion in GRB 030329
  97. GRB 030329 and SN 2003dh
  98. GRB030329, optical position
  99. GRB 030329 VLBA Observations
  100. CORRECTION TO IPN TRIANGULATION OF GRB050403

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