Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
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"
  1. IPN triangulation of GRB030709 (annulus)
  2. GRB030706 triangulation (single large error box)
  3. IPN triangulation of GRB030706 (annulus)
  4. IPN triangulation of GRB030629 (annulus)
  5. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  6. 030629 NOT a real GRB
  7. GRB030329, optical observation in May
  8. IPN triangulation of GRB030626 (single large error box)
  9. IPN triangulation of GRB030626 (two large error boxes)
  10. GRB030329: second XMM-Newton observation
  11. GRB030418: R optical observations
  12. HETE detection of burst from SGR1806-20
  13. GRB030329 -- RATAN-600 data in April-May
  14. Final IPN error ellipse for GRB021206 (the polarized GRB)
  15. GRB 021206, Radio afterglow candidate
  16. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  17. IPN triangulation of GRB030607 (annulus)
  18. IPN triangulation of GRB030606 (two alternate error boxes)
  19. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  20. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  21. IPN triangulation of GRB030605B (annulus)
  22. GRB 030528: Optical Observations
  23. IPN triangulation of GRB030605 (annulus)
  24. GRB 030528: tentative NIR counterpart
  25. GRB 030528, radio observations
  26. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  27. GRB030329, further radio observations at GMRT
  28. GRB030528, BVRI field photometry
  29. IPN triangulation of GRB030601 (annulus)
  30. GRB030329, SPM optical observations
  31. GRB030528: Chandra TOO Planned
  32. GRB 030519B: optical observations.
  33. MASTER: optical observation GRB030601
  34. GRB030528(=H2724): Revised SXC Localization
  35. GRB 030329: optical observations
  36. GRB 030329/SN 2003dh: Jitter Episode
  37. GRB 030528, Teramo optical observation
  38. GRB 030528 Bisei optical observation
  39. GRB030528 (H2724): A long GRB localized by HETE
  40. GRB 030329: Correction to GCN 2254
  41. GRB 030329: Optical Observations
  42. GRB 030528: Optical observations at RIKEN
  43. GRB 030528 (=H2724) Kyoto optical observation
  44. IPN triangulation of GRB030523B (annulus)
  45. GRB 030416: Optical Observations
  46. GRB 030329: Planned XMM-Newton Observation
  47. IPN triangulation of GRB030523 (annulus)
  48. GRB 030329: optical photometry at various french observatories
  49. GRB 030329: optical photometry at Belesta observatory (France)
  50. GRB030329, Optical observations
  51. GRB 030329/SN 2003dh: Possible increase in brightness
  52. GRB 030329: HST ACS Observations of the Host
  53. GRB 030329 Optical Observations
  54. GRB030329: XMM-Newton observation
  55. GRB 021004: HST observations
  56. GRB030324: Further Observations of the Candidate Optical Afterglow
  57. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  58. IPN triangulation of GRB030519B=H2716 (small error box)
  59. GRB 030418: Second Epoch Optical Observations with Magellan
  60. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  61. IPN triangulation of GRB030519 (annulus)
  62. IPN triangulation of GRB030518C (annulus)
  63. IPN triangulation of GRB030518B (annulus)
  64. IPN triangulation of GRB030518A (annulus)
  65. IPN triangulation of GRB030514 (annulus)
  66. HETE GRB030329, correction to Rc Observations in Loiano
  67. IPN triangulation of GRB030513 (annulus)
  68. IPN triangulation of GRB030509B (annulus)
  69. GRB 030329: Optical limit (contemporaneous imaging)
  70. GRB 030501: final TAROT limits
  71. IPN triangulation of GRB030509 (small errror box)
  72. IPN triangulation of GRB030509 - correction
  73. IPN triangulation of GRB030509 (single error box)
  74. GRB030329: RTT150 optical observations
  75. GRB030329, BVRI photometry
  76. GRB030429, refiend optical brightness
  77. GRB 030329: Optical limit (contemporaneous photography)
  78. GRB030418, BVRcIc field photometry
  79. GRB 030429: Redshift of neighbor galaxy
  80. GRB030429, BVRcIc field photometry
  81. GRB030429: RTT150 optical obs., correction to GCN 2208
  82. GRB 030329: High-Resolution Spectroscopy of the Host
  83. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  84. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  85. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  86. GRB030429: RTT150 optical observations, a possible host galaxy
  87. IPN triangulation of GRB030506 (annulus)
  88. IPN triangulation of GRB030505B (large error box)
  89. IPN triangulation of GRB030505A (annulus)
  90. GRB030329: RTT150 optical observations and upper limit for a host
  91. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  92. GRB030501, optical observation
  93. GRB030501 observation report
  94. GRB030501C triangulation (annulus)
  95. GRB030501 triangulation (correction to GCN 2194)
  96. GRB030329: RTT150 optical observations and upper limit for a host
  97. GRB 030429: Radio Observations
  98. GRB 030429: redshift from VLT spectroscopy
  99. GRB 030429: IR photometry with IRSF/SIRIUS
  100. GRB030501B triangulation (single error box)

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