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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. GRB030329, SPM optical observations (Correction)
  2. GRB030329, SPM optical observations
  3. GRB 030329, the review of the sky area in plate archive (1950-1998)
  4. GRB 030329: Spectral Evolution of SN 2003dh
  5. Optical Observations of GRB 030418 with Magellan
  6. GRB 030329: optical spectropolarimetry at VLT
  7. IPN triangulation of GRB030422C (annulus)
  8. IPN triangulation of GRB030422B (annulus)
  9. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  10. GRB030329: optical polarization
  11. IPN triangulation of GRB030422 (two large error boxes)
  12. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  13. GRB030329, optical observation
  14. IPN triangulation of GRB030421 (annulus)
  15. MASTER:optical observations GRB030418
  16. MASTER:optical observations probable GRB030414
  17. GRB030329: 444 AAVSO Measurements
  18. IPN triangulation of GRB030419 (annulus)
  19. MASTER:optical observations GRB030416
  20. ROTSE-III prompt optical detections of GRB 030418
  21. GRB030418: Upper limits from recent and historical observations.
  22. GRB030418: Kiso near infrared observations
  23. GRB 030418: Optical afterglow
  24. GRB 030418: Finder for afterglow candidate
  25. GRB 030418: Optical afterglow candidate
  26. GRB 030329 OT position
  27. GRB030329: Optical Observations
  28. OT GRB 030329: early UBVRcIc spectral evolution
  29. GRB030329, UBVRI polarimetry, R-polarization
  30. GRB 030329: SARA Optical Observations
  31. OT GRB 030329: early spectrum
  32. GRB030329: VR Photometry at TNG
  33. GRB030324: Candidate Optical Afterglow (Erratum)
  34. GRB030324: Candidate Optical Afterglow
  35. IPN triangulation of GRB030414 (small error box)
  36. GRB 030413: Optical Observations
  37. GRB 030329 Rc observations
  38. IPN triangulation of GRB030413 (small error box)
  39. IPN triangulation of GRB030410 (annulus)
  40. Superluminal motion in GRB 030329 (Correction)
  41. Superluminal motion in GRB 030329
  42. GRB 030329 and SN 2003dh
  43. GRB030329, optical position
  44. GRB 030329 VLBA Observations
  45. CORRECTION TO IPN TRIANGULATION OF GRB050403
  46. IPN triangulation of GRB030406 (small error box)
  47. IPN triangulation of GRB050403 (small error box)
  48. IPN triangulation of GRB030403 (annulus)
  49. GRB 030329: BVRI photometry at Asiago
  50. GRB 030329, light curve flattens
  51. GRB 030329: VLT V-band photometry
  52. If the SN/GRB connection confirmed
  53. GRB 030329: Supernova Confirmed
  54. GRB030329: RTT150 optical observations
  55. GRB030329: Near Infrared Observations at Gunma
  56. GRB030329: HET spectroscopic monitoring
  57. Kiso observation of the GRB030329 at April 6
  58. GRB 030329, color evolution
  59. GRB030328, UBVRcIc field photometry
  60. GRB030329: Optical observcations
  61. GRB030329: BV photographic observations
  62. GRB 030329 Optical observations
  63. GRB 030329, color evolution
  64. GRB 030329: possible color change
  65. GRB030329: RTT150 optical observations
  66. GRB 030329: Supernova Spectrum Emerging
  67. GRB030329: Kiso B and R band observations
  68. GRB030329: RTT150 optical observation
  69. GRB030329: More AAVSO VR obs
  70. GRB030328: R upper limit after 6 hours by MASTER
  71. GRB 030329: BV photographic observations
  72. GRB 030329: SARA Optical Observations
  73. GRB 030329: SARA Optical Observations
  74. GRB030329, fading resumes
  75. GRB 030329, BVRI photometry
  76. GRB030329: Optical observations
  77. SDSS 0.5m PT observations of GRB030329 (correction)
  78. SDSS 0.5m PT observations of GRB030329
  79. GRB 030329, Optical observations
  80. GRB 030329, nearby galaxies
  81. GRB030329, cessation of fading
  82. GRB030329: final R-band light curve by MASTER
  83. GRB030329 - more 15 GHz radio data
  84. GRB030329 Radio 23/43/90 GHz observations at Nobeyama
  85. GRB 030329: Sub-millimeter detection
  86. GRB 030329: SARA Optical Observations
  87. GRB 030329: SARA Optical Observations
  88. OT GRB light curves and SN predictions
  89. GRB030329, optical observation
  90. GRB030329, optical observation
  91. GRB030329, new UBVRcIc field photometry
  92. GRB 030329, light curve and SN prediction
  93. GRB030329: optical observations at Tokyo Tech
  94. GRB 030329: optical observations
  95. GRB030329: multiple re-brightening phases
  96. GRB 030329, BRI photometry
  97. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  98. GRB 030329 , SPM optical observations
  99. GRB030329: Optical observations at Teramo
  100. GRB 030329: Radio observations at GMRT

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