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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"

45423 results found.

  1. MASTER:optical observations probable GRB030414
  2. GRB030329: 444 AAVSO Measurements
  3. IPN triangulation of GRB030419 (annulus)
  4. MASTER:optical observations GRB030416
  5. ROTSE-III prompt optical detections of GRB 030418
  6. GRB030418: Upper limits from recent and historical observations.
  7. GRB030418: Kiso near infrared observations
  8. GRB 030418: Optical afterglow
  9. GRB 030418: Optical afterglow candidate
  10. GRB 030329 OT position
  11. GRB030329: Optical Observations
  12. OT GRB 030329: early UBVRcIc spectral evolution
  13. GRB030329, UBVRI polarimetry, R-polarization
  14. GRB 030329: SARA Optical Observations
  15. OT GRB 030329: early spectrum
  16. GRB030329: VR Photometry at TNG
  17. GRB030324: Candidate Optical Afterglow (Erratum)
  18. GRB030324: Candidate Optical Afterglow
  19. IPN triangulation of GRB030414 (small error box)
  20. GRB 030413: Optical Observations
  21. GRB 030329 Rc observations
  22. IPN triangulation of GRB030413 (small error box)
  23. IPN triangulation of GRB030410 (annulus)
  24. Superluminal motion in GRB 030329 (Correction)
  25. Superluminal motion in GRB 030329
  26. GRB 030329 and SN 2003dh
  27. GRB030329, optical position
  28. GRB 030329 VLBA Observations
  29. CORRECTION TO IPN TRIANGULATION OF GRB050403
  30. IPN triangulation of GRB030406 (small error box)
  31. IPN triangulation of GRB050403 (small error box)
  32. IPN triangulation of GRB030403 (annulus)
  33. GRB 030329: BVRI photometry at Asiago
  34. GRB 030329, light curve flattens
  35. GRB 030329: VLT V-band photometry
  36. GRB 030329: Supernova Confirmed
  37. GRB030329: RTT150 optical observations
  38. GRB030329: Near Infrared Observations at Gunma
  39. GRB030329: HET spectroscopic monitoring
  40. Kiso observation of the GRB030329 at April 6
  41. GRB 030329, color evolution
  42. GRB030328, UBVRcIc field photometry
  43. GRB030329: Optical observcations
  44. GRB030329: BV photographic observations
  45. GRB 030329 Optical observations
  46. GRB 030329, color evolution
  47. GRB 030329: possible color change
  48. GRB030329: RTT150 optical observations
  49. GRB 030329: Supernova Spectrum Emerging
  50. GRB030329: Kiso B and R band observations
  51. GRB030329: RTT150 optical observation
  52. GRB030329: More AAVSO VR obs
  53. GRB030328: R upper limit after 6 hours by MASTER
  54. GRB 030329: BV photographic observations
  55. GRB 030329: SARA Optical Observations
  56. GRB 030329: SARA Optical Observations
  57. GRB030329, fading resumes
  58. GRB 030329, BVRI photometry
  59. GRB030329: Optical observations
  60. SDSS 0.5m PT observations of GRB030329 (correction)
  61. SDSS 0.5m PT observations of GRB030329
  62. GRB 030329, Optical observations
  63. GRB 030329, nearby galaxies
  64. GRB030329, cessation of fading
  65. GRB030329: final R-band light curve by MASTER
  66. GRB030329 - more 15 GHz radio data
  67. GRB030329 Radio 23/43/90 GHz observations at Nobeyama
  68. GRB 030329: Sub-millimeter detection
  69. GRB 030329: SARA Optical Observations
  70. GRB 030329: SARA Optical Observations
  71. OT GRB light curves and SN predictions
  72. GRB030329, optical observation
  73. GRB030329, optical observation
  74. GRB030329, new UBVRcIc field photometry
  75. GRB 030329, light curve and SN prediction
  76. GRB030329: optical observations at Tokyo Tech
  77. GRB 030329: optical observations
  78. GRB030329: multiple re-brightening phases
  79. GRB 030329, BRI photometry
  80. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  81. GRB 030329 , SPM optical observations
  82. GRB030329: Optical observations at Teramo
  83. GRB 030329: Radio observations at GMRT
  84. Further AAVSO V,B,R observations of GRB030329
  85. GRB 030329: Additional Mt. Laguna Optical Observations
  86. GRB 030329: SARA Optical Observations
  87. GRB 030329: Observations with ANDICAM
  88. GRB030329: Optical observations
  89. GRB030329: further optical photometry and evidence for a light curve discontinuity
  90. GRB 030329: Correction to GCN 2056
  91. GRB 030329: fitting parameters and re-brightening
  92. GRB 030329: KAIT optical photometry
  93. GRB030329 Further RBO Optical Observations
  94. triangulation of GRB 030331 (single error box)
  95. GRB030329 - OT rebrightens
  96. GRB 030329: SARA Optical Observations
  97. AAVSO V & R observations of GRB030329
  98. IPN triangulation of GRB030331 (annulus)
  99. GRB 030329: optical observations
  100. IPN triangulation of GRB030329b (large error box)

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