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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"

3344 results found.

  1. XRF030723: Palomar observations and proposed counterpart
  2. GRB030329: second XMM-Newton observation
  3. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  4. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  5. GRB 030528: tentative NIR counterpart
  6. GRB 030329: Optical limit (contemporaneous photography)
  7. GRB 030429: IR photometry with IRSF/SIRIUS
  8. GRB030501: TAROT candidate afterglow present in archival images
  9. GRB 030429: confirmation of afterglow candidate
  10. GRB030418: Kiso near infrared observations
  11. GRB030329: Near Infrared Observations at Gunma
  12. GRB 030329: fading X-ray afterglow with RXTE
  13. XMM-Newton observation of GRB030227
  14. GRB 030115: Further IR observations with IRSF/SIRIUS
  15. GRB 030115: IR observations with IRSF/SIRIUS
  16. GRB 021201, optical observations
  17. GRB 021201 (short/hard), NOT observations
  18. Chandra observation of the IPN error box of GRB021201 (short/hard)
  19. Detection of activity from SGR 1900+14 with the RXTE/PCA
  20. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  21. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  22. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  23. SGR-like Bursts from the AXP 1E 2259+586
  24. GRB 020418, optical/near-IR observations
  25. GRB020531, optical observations
  26. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  27. GRB 020321: Candidate X-ray Counterparts
  28. GRB 020331: Candidate Optical Afterglow
  29. GRB 020331: NIR Observations
  30. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  31. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  32. GRB 011121: NIR observations, host galaxy?
  33. GRB 011121: Detection of Bright IR Counterpart
  34. SGR 1900+14 : RXTE observations
  35. GRB 001204: Ks observations
  36. GRB 001212 possible OA in 2MASS
  37. GRB 001109: deep JHK upper limits
  38. The Likely Optical/Infrared Afterglow of GRB 001011
  39. SGR 1806-20 burst activity
  40. GRB 000418: Detection of the Host Galaxy
  41. X-ray Afterglow of GRB 000529
  42. IR observations of GRB991216
  43. BeppoSAX NFI Observation of GRB991106
  44. GRB980703: Radio transient

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