Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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. XRF030723 Radio Observations
  2. XRF 030723: confirmation of fading optical counterpart
  3. XRF030723(=H2777): Chandra Observations
  4. XRF 030723: VLT spectra
  5. Magellan Observations of XRF030723 (=H2777)
  6. GRB030723: Upper limits from historical observations
  7. GRB030725, possible optical transient
  8. XRF030723: Palomar observations and proposed counterpart
  9. GRB030725 (=H2779): A Bright GRB Localized by HETE
  10. XRF030723: optical observations
  11. XRF030723 (= H2777): Chandra Observations Scheduled
  12. XRF030723, BVRcIc field photometry correction
  13. XRF030723, ROTSE-III Early Observations
  14. XRF030723, BVRcIc field photometry
  15. XRF 030723, optical observations
  16. XRF030723, optical observations
  17. XRF 030723, optical observations
  18. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  19. GRB030723, optical observations
  20. Konus-Wind detection of the bursts from SGR1806-20 region
  21. IBAS GRB Alerts 969 970
  22. SGR 1806-20, submm observations
  23. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  24. IPN triangulation of GRB030717 (annulus)
  25. RXTE PCA Observations of SGR1806-20 Region
  26. GRB030329: Subaru Optical Spectroscopy
  27. Triangulation of GRB030715 (single large error box)
  28. Triangulation of GRB030714 (single large error box)
  29. 030716 NOT a GRB
  30. IPN triangulation of GRB030714 (two large error boxes)
  31. IPN triangulation of GRB030715 (two large error boxes)
  32. GRB030329: RTT150 optical observations
  33. GRBlog: Compilation of all GCN Circ. data
  34. IPN detection of renewed activity from SGR1806-20
  35. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  36. IPN triangulation of GRB030710 (annulus)
  37. IPN triangulation of GRB030709 (annulus)
  38. GRB030706 triangulation (single large error box)
  39. IPN triangulation of GRB030706 (annulus)
  40. IPN triangulation of GRB030629 (annulus)
  41. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  42. 030629 NOT a real GRB
  43. GRB030329, optical observation in May
  44. IPN triangulation of GRB030626 (single large error box)
  45. IPN triangulation of GRB030626 (two large error boxes)
  46. GRB030329: second XMM-Newton observation
  47. GRB030418: R optical observations
  48. HETE detection of burst from SGR1806-20
  49. GRB030329 -- RATAN-600 data in April-May
  50. Final IPN error ellipse for GRB021206 (the polarized GRB)
  51. GRB 021206, Radio afterglow candidate
  52. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  53. IPN triangulation of GRB030607 (annulus)
  54. IPN triangulation of GRB030606 (two alternate error boxes)
  55. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  56. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  57. IPN triangulation of GRB030605B (annulus)
  58. GRB 030528: Optical Observations
  59. IPN triangulation of GRB030605 (annulus)
  60. GRB 030528: tentative NIR counterpart
  61. GRB 030528, radio observations
  62. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  63. GRB030329, further radio observations at GMRT
  64. GRB030528, BVRI field photometry
  65. IPN triangulation of GRB030601 (annulus)
  66. GRB030329, SPM optical observations
  67. GRB030528: Chandra TOO Planned
  68. GRB 030519B: optical observations.
  69. MASTER: optical observation GRB030601
  70. GRB030528(=H2724): Revised SXC Localization
  71. GRB 030329: optical observations
  72. GRB 030329/SN 2003dh: Jitter Episode
  73. GRB 030528, Teramo optical observation
  74. GRB 030528 Bisei optical observation
  75. GRB030528 (H2724): A long GRB localized by HETE
  76. GRB 030329: Correction to GCN 2254
  77. GRB 030329: Optical Observations
  78. GRB 030528: Optical observations at RIKEN
  79. GRB 030528 (=H2724) Kyoto optical observation
  80. IPN triangulation of GRB030523B (annulus)
  81. GRB 030416: Optical Observations
  82. GRB 030329: Planned XMM-Newton Observation
  83. IPN triangulation of GRB030523 (annulus)
  84. GRB 030329: optical photometry at various french observatories
  85. GRB 030329: optical photometry at Belesta observatory (France)
  86. GRB030329, Optical observations
  87. GRB 030329/SN 2003dh: Possible increase in brightness
  88. GRB 030329: HST ACS Observations of the Host
  89. GRB 030329 Optical Observations
  90. GRB030329: XMM-Newton observation
  91. GRB 021004: HST observations
  92. GRB030324: Further Observations of the Candidate Optical Afterglow
  93. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  94. IPN triangulation of GRB030519B=H2716 (small error box)
  95. GRB 030418: Second Epoch Optical Observations with Magellan
  96. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  97. IPN triangulation of GRB030519 (annulus)
  98. IPN triangulation of GRB030518C (annulus)
  99. IPN triangulation of GRB030518B (annulus)
  100. IPN triangulation of GRB030518A (annulus)

Advanced

Download all Circulars as a .tar.gz archive:
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