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"
  1. IPN triangulation of GRB030518B (annulus)
  2. IPN triangulation of GRB030518A (annulus)
  3. IPN triangulation of GRB030514 (annulus)
  4. HETE GRB030329, correction to Rc Observations in Loiano
  5. IPN triangulation of GRB030513 (annulus)
  6. IPN triangulation of GRB030509B (annulus)
  7. GRB 030329: Optical limit (contemporaneous imaging)
  8. GRB 030501: final TAROT limits
  9. IPN triangulation of GRB030509 (small errror box)
  10. IPN triangulation of GRB030509 - correction
  11. IPN triangulation of GRB030509 (single error box)
  12. GRB030329: RTT150 optical observations
  13. GRB030329, BVRI photometry
  14. GRB030429, refiend optical brightness
  15. GRB 030329: Optical limit (contemporaneous photography)
  16. GRB030418, BVRcIc field photometry
  17. GRB 030429: Redshift of neighbor galaxy
  18. GRB030429, BVRcIc field photometry
  19. GRB030429: RTT150 optical obs., correction to GCN 2208
  20. GRB 030329: High-Resolution Spectroscopy of the Host
  21. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  22. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  23. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  24. GRB030429: RTT150 optical observations, a possible host galaxy
  25. IPN triangulation of GRB030506 (annulus)
  26. IPN triangulation of GRB030505B (large error box)
  27. IPN triangulation of GRB030505A (annulus)
  28. GRB030329: RTT150 optical observations and upper limit for a host
  29. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  30. GRB030501, optical observation
  31. GRB030501 observation report
  32. GRB030501C triangulation (annulus)
  33. GRB030501 triangulation (correction to GCN 2194)
  34. GRB030329: RTT150 optical observations and upper limit for a host
  35. GRB 030429: Radio Observations
  36. GRB 030429: redshift from VLT spectroscopy
  37. GRB 030429: IR photometry with IRSF/SIRIUS
  38. GRB030501B triangulation (single error box)
  39. GRB 030329 Optical Observations
  40. GRB030328, optical observation
  41. GRB 030329, BVRI photometry
  42. GRB030429: Optical Observations
  43. GRB030501: TAROT candidate afterglow present in archival images
  44. GRB 030501: TAROT possible candidate counterpart
  45. IPN triangulation of GRB030501 (IBIS event; annulus)
  46. IPN triangulation of GRB030501B (annulus)
  47. GRB 030429: confirmation of afterglow candidate
  48. GRB030429, possible optical counterpart
  49. GRB030501 localized by INTEGRAL
  50. GRB030425: CrAO optical observation
  51. IPN triangulation of GRB030429 (annulus)
  52. IPN triangulation of GRB030428 (two large error boxes)
  53. GRB 030329 Oprical observations in Rozhen observatory
  54. GRB 030429: ROTSE-III observations
  55. GRB 030324: Radio Observations
  56. GRB030329 observed as a sudden ionospheric disturbance (SID)
  57. IPN triangulation of GRB030426 (annulus)
  58. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  59. IPN triangulation of GRB030425 (single error box)
  60. GRB030329, SPM optical observations (Correction)
  61. GRB030329, SPM optical observations
  62. GRB 030329, the review of the sky area in plate archive (1950-1998)
  63. GRB 030329: Spectral Evolution of SN 2003dh
  64. Optical Observations of GRB 030418 with Magellan
  65. GRB 030329: optical spectropolarimetry at VLT
  66. IPN triangulation of GRB030422C (annulus)
  67. IPN triangulation of GRB030422B (annulus)
  68. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  69. GRB030329: optical polarization
  70. IPN triangulation of GRB030422 (two large error boxes)
  71. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  72. GRB030329, optical observation
  73. IPN triangulation of GRB030421 (annulus)
  74. MASTER:optical observations GRB030418
  75. MASTER:optical observations probable GRB030414
  76. GRB030329: 444 AAVSO Measurements
  77. IPN triangulation of GRB030419 (annulus)
  78. MASTER:optical observations GRB030416
  79. ROTSE-III prompt optical detections of GRB 030418
  80. GRB030418: Upper limits from recent and historical observations.
  81. GRB030418: Kiso near infrared observations
  82. GRB 030418: Optical afterglow
  83. GRB 030418: Finder for afterglow candidate
  84. GRB 030418: Optical afterglow candidate
  85. GRB 030329 OT position
  86. GRB030329: Optical Observations
  87. OT GRB 030329: early UBVRcIc spectral evolution
  88. GRB030329, UBVRI polarimetry, R-polarization
  89. GRB 030329: SARA Optical Observations
  90. OT GRB 030329: early spectrum
  91. GRB030329: VR Photometry at TNG
  92. GRB030324: Candidate Optical Afterglow (Erratum)
  93. GRB030324: Candidate Optical Afterglow
  94. IPN triangulation of GRB030414 (small error box)
  95. GRB 030413: Optical Observations
  96. GRB 030329 Rc observations
  97. IPN triangulation of GRB030413 (small error box)
  98. IPN triangulation of GRB030410 (annulus)
  99. Superluminal motion in GRB 030329 (Correction)
  100. Superluminal motion in GRB 030329

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