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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"

15251 results found.

  1. XRF030723: optical observations
  2. XRF030723, BVRcIc field photometry
  3. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  4. GRB030723, optical observations
  5. Konus-Wind detection of the bursts from SGR1806-20 region
  6. RXTE PCA Observations of SGR1806-20 Region
  7. GRB030329: RTT150 optical observations
  8. GRBlog: Compilation of all GCN Circ. data
  9. GRB030329, optical observation in May
  10. GRB030329: second XMM-Newton observation
  11. GRB030418: R optical observations
  12. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  13. GRB 030528: Optical Observations
  14. GRB030329, further radio observations at GMRT
  15. GRB030528: Chandra TOO Planned
  16. MASTER: optical observation GRB030601
  17. GRB030528(=H2724): Revised SXC Localization
  18. GRB030528 (H2724): A long GRB localized by HETE
  19. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  20. GRB 030418: Second Epoch Optical Observations with Magellan
  21. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  22. GRB 030501: final TAROT limits
  23. GRB030329, BVRI photometry
  24. GRB030429, refiend optical brightness
  25. GRB030429, BVRcIc field photometry
  26. GRB 030329: High-Resolution Spectroscopy of the Host
  27. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  28. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  29. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  30. GRB030501 triangulation (correction to GCN 2194)
  31. GRB 030429: IR photometry with IRSF/SIRIUS
  32. GRB030328, optical observation
  33. GRB 030329, BVRI photometry
  34. GRB030501: TAROT candidate afterglow present in archival images
  35. GRB 030501: TAROT possible candidate counterpart
  36. GRB030425: CrAO optical observation
  37. GRB030329 observed as a sudden ionospheric disturbance (SID)
  38. Optical Observations of GRB 030418 with Magellan
  39. GRB030329, optical observation
  40. MASTER:optical observations probable GRB030414
  41. GRB030329: 444 AAVSO Measurements
  42. ROTSE-III prompt optical detections of GRB 030418
  43. GRB030418: Kiso near infrared observations
  44. GRB030329, UBVRI polarimetry, R-polarization
  45. GRB 030329 VLBA Observations
  46. GRB 030329, light curve flattens
  47. If the SN/GRB connection confirmed
  48. GRB 030329: Supernova Confirmed
  49. GRB030329: HET spectroscopic monitoring
  50. GRB 030329, color evolution
  51. GRB 030329, color evolution
  52. GRB030329: Kiso B and R band observations
  53. GRB030329: More AAVSO VR obs
  54. GRB030329, fading resumes
  55. GRB 030329, BVRI photometry
  56. GRB030329, optical observation
  57. GRB030329, new UBVRcIc field photometry
  58. GRB 030329, light curve and SN prediction
  59. GRB030329: multiple re-brightening phases
  60. GRB 030329, BRI photometry
  61. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  62. GRB 030329: Additional Mt. Laguna Optical Observations
  63. GRB 030329: Observations with ANDICAM
  64. GRB 030329: fitting parameters and re-brightening
  65. GRB030329 Further RBO Optical Observations
  66. triangulation of GRB 030331 (single error box)
  67. GRB 030329, R-band light curve
  68. GRB 030329 RBO V Optical Observations
  69. GRB 030329, optical photometry
  70. INTEGRAL GRB 030331
  71. GRB030329: R band light curve by MASTER
  72. GRB030329 - Light curve flattening
  73. GRB 030329: SARA Optical Observations
  74. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  75. GRB 030329: Light curve observed during the change of its slope.
  76. Redshift of GRB 030329
  77. GRB030329: ROTSE network observes steepening of decay curve
  78. GRB 030329: Optical decay and synthesis
  79. GRB 030329: Optical pre-Imaging
  80. GRB 030329: visual observations
  81. GRB030328: R optical observation
  82. GRB030328: X-ray Afterglow Observed with Chandra
  83. GRB 030329, R-band observations, supplement
  84. GRB 030329: optical observations
  85. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  86. GRB 030329: Optical Afterglow Observations
  87. GRB 030328 Optical Observations
  88. GRB030328: Decay index
  89. GRB 030328: Optical observations
  90. GRB 030328: optical observations
  91. GRB 030329: Optical afterglow fading
  92. GRB030328: optical spectroscopy at TNG
  93. GRB030328: optical photometry at the TNG
  94. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  95. GRB030323 optical observations
  96. GRB 030323: SARA Optical Observations
  97. GRB030323: V, R, I photometry
  98. GRB030324, Optical Observations
  99. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  100. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM

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