Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

28052 results found.

  1. Superluminal motion in GRB 030329
  2. GRB030329, optical position
  3. IPN triangulation of GRB030406 (small error box)
  4. IPN triangulation of GRB050403 (small error box)
  5. GRB 030329: BVRI photometry at Asiago
  6. GRB 030329: VLT V-band photometry
  7. Kiso observation of the GRB030329 at April 6
  8. GRB 030329, color evolution
  9. GRB030328, UBVRcIc field photometry
  10. GRB 030329 Optical observations
  11. GRB030329: Kiso B and R band observations
  12. GRB030328: R upper limit after 6 hours by MASTER
  13. SDSS 0.5m PT observations of GRB030329 (correction)
  14. SDSS 0.5m PT observations of GRB030329
  15. GRB030329: final R-band light curve by MASTER
  16. GRB030329, optical observation
  17. GRB030329, new UBVRcIc field photometry
  18. GRB 030329, light curve and SN prediction
  19. GRB 030329, BRI photometry
  20. GRB030328: Full Observation, X-ray Fading and Spectrum Measured
  21. GRB030329: Optical observations at Teramo
  22. GRB 030329: Radio observations at GMRT
  23. Further AAVSO V,B,R observations of GRB030329
  24. GRB 030329: Additional Mt. Laguna Optical Observations
  25. GRB 030329: Observations with ANDICAM
  26. GRB030329: further optical photometry and evidence for a light curve discontinuity
  27. triangulation of GRB 030331 (single error box)
  28. GRB 030329: optical observations
  29. Photometry of GRB030329 - Constant OT Magnitude
  30. GRB030329 - OT brightens
  31. GRB 030329, optical photometry
  32. GRB 030324: Optical and NIR Observations
  33. GRB030329: R band light curve by MASTER
  34. GRB030329 - Light curve flattening
  35. GRB 030324, optical search
  36. GRB 030329, optical observations
  37. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  38. GRB030329a: detection by Konus-Wind
  39. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  40. GRB030329, BVRcIc field photometry
  41. GRB030329, SPM optical observations
  42. GRB 030329: Optical decay and synthesis
  43. GRB030329 optical observations
  44. GRB 030329: Optical pre-Imaging
  45. GRB 030329: Upper limit from 5.6 hours before trigger
  46. GRB030328: X-ray Afterglow Observed with Chandra
  47. GRB 030329, R-band observations
  48. GRB 030329: OT B and R photometry, decline rate
  49. GRB030329: Upper limits from recent and historical observations.
  50. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  51. GRB 030329: Optical Afterglow Observations
  52. GRB 030328: optical observations
  53. GRB 030329: Optical afterglow fading
  54. GRB 030328: OT photometry
  55. GRB030328: optical spectroscopy at TNG
  56. GRB030328: optical photometry at the TNG
  57. VLT spectra of GRB 030328
  58. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  59. GRB 030328: Optical observations
  60. GRB030324 optical observation
  61. GRB030131, BVRcIc field photometry
  62. Possible GRB030323 localized by INTEGRAL
  63. GRB030323: Detection on 2003/03/24
  64. IPN triangulation of GRB030326 (single small error box)
  65. IPN triangulation of GRB030325 (two small error boxes)
  66. GRB030323: V, R, I photometry
  67. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  68. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  69. VLT/FORS2 spectra of GRB 030323
  70. GRB030323, optical observations
  71. GRB030324, BVRcIc field photometry
  72. GRB030323, BVRcIc field calibration
  73. IPN triangulation of GRB030320 (small error box)
  74. Possible GRB 030320 localized by INTEGRAL
  75. IPN triangulation of GRB030306 (single small error box - REVISED)
  76. IPN triangulation of GRB030306 (single small error box)
  77. IPN triangulation of GRB030306 (two small error boxes)
  78. GRB030226, BVRc observations
  79. Chandra detection of the X-ray afterglow of GRB 030226
  80. GRB030227: Kiso optical upper limit
  81. GRB030227, BVRcIc field photometry
  82. GRB030226, BVRcIc field calibration
  83. GRB 030228, optical observations
  84. GRB 030227: Confirmed Optical Afterglow (S1-A)
  85. GRB 030227: fading of candidate optical afterglow 'S1-A'
  86. GRB030227:Optical observations
  87. GRB 030227, possible optical counterpart of XMM-Newton source
  88. GRB030227 - faint tentative OT candidate
  89. GRB 030226, optical observations
  90. XMM-Newton observation of GRB030227
  91. GRB030227: Kiso optical observations
  92. GRB 030227: Kyoto optical observation
  93. GRB 030226, optical light curve
  94. GRB030227 localized by INTEGRAL
  95. GRB 030226 : Predicted light curve
  96. GRB030226: ESI spectroscopy
  97. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  98. GRB 030226 simultaneous optical observations
  99. GRB 030226, optical observations
  100. GRB030226: Optical decay index

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov