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').
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"15985 results found.
- GRB 080129: Gemini-South photometry
- GRB 080129: GROND detection in all bands, and fading
- GRB 080129: GROND detection of the optical/NIR afterglow, and fading
- GRB 080129: Gemini-South Imaging Observations
- Transient 080109/SN 2008D: Spectroscopic Evolution
- SNe 2008D and 2007uy: Chandra Detections
- Transient 080109/SN 2008D: Spectroscopic Evolution and Re-Classification
- X-ray transient in NGC 2770: RTT150 optical observations
- GRB 080120: GROND confirmation of the optical afterglow
- GRB 080120: Swift-XRT refined analysis
- GRB 080120: GROND detection
- XRF 080109 / SN 2008D: optical observations
- NGC 2770B has the same redshift as NGC 2770
- Swift UVOT Monitoring of the SN 2008D Brightening (Transient in NGC 2770)
- XRF 080109 / SN 2008D: spectroscopic evolution
- XRF 080109 / SN 2008D: UKIRT JHK imaging
- optical observations, XRT in NGC 2770
- XRF 080109/SN 2008D: PROMPT Optical Imaging
- Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
- Discovery of Radio Emission from Transient in NGC 2770
- XRB 080109/SN 2008D: Early decline in brightness and change in colors
- Detailed Spectroscopic ID of SN 2008D (Transient in NGC 2770)
- Transient in NGC 2770: spectroscopic evidence for a SN
- Refined Swift UVOT Analysis of SN 2008D (Transient in NGC 2770)
- Opticall follow-ups for the X-ray transient in NGC 2770
- X-ray transient in NGC 2770: Optical observations with Astrotel-Caucasus
- Optical Spectroscopy of the Transient in NGC 2770
- Swift UVOT Observations of the X-ray transient in NGC 2770
- Early OT detection of XRF in NGC 2770 in Asiago frames
- Bright X-ray transient / possible XRF in NGC 2770: TNG R imaging
- Possible XRF in NGC 2770 - NOT observations of the optical counterpart
- Bright X-ray Transient (a XRF? ) in NGC 2770 - A SN optical counterpart?
- Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
- GRB 071227: optical afterglow
- GRB 071227: Swift-XRT refined analysis
- GRB 071227: REM NIR and Optical observations
- GRB071020: optical observations
- GRB 070429B: Possible UVOT Detection of an Optical Afterglow
- GRB 071112C: Optical/NIR observations
- GRB071122: Swift/UVOT Observations
- GRB 071122: MASTER optical observation
- GRB 071122 Swift-XRT refined analysis
- GRB071122: Gemini Absorption redshift
- GRB 071122: P60 Optical Afterglow Candidate
- GRB 071122: ROTSE-III Optical Limits
- GRB 071118: P60 Observations
- GRB071118 MITSuME OAO optical observation
- Swift/UVOT observations of GRB071118
- GRB 071117: Swift-XRT revised position
- GRB 071117: Gemini Optical Afterglow Discovery
- GRB 071117: TAROT La Silla observatory optical observations
- GRB 071117: Las Campanas optical observations
- GRB 071112C: Optical and NIR data observed with KANATA
- GRB 071112C: WSRT Radio Observations
- GRB 071112C: optical observation
- GRB 071112C: optical observation
- GRB 071112C: emission lines and refined VLT redshift
- GRB 071112C MITSuME Akeno early optical observation
- GRB071112C MITSuME Okayama Optical Observation
- GRB 071112C: Optical observations at Crni Vrh
- GRB 071112C: VLT redshift
- GRB 071112B: Gemini Optical Imaging (Correction)
- GRB 071112B: Gemini Optical Imaging
- GRB071112C: NOT observations
- GRB 071112C : Lulin R-band observation
- GRB 071112C: RTT150 optical observations
- GRB 071112C: TAROT Calern observatory optical observations
- GRB 071112C: Optical and NIR afterglows observed with KANATA
- GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
- GRB 071112B: ROTSE-III Rapid Optical Limits
- GRB 071112C: Swift detection of a burst with an optical counterpart
- GRB 071109: TAROT Calern observatory optical observations
- GRB 071109: BOOTES-2 prompt optical observations
- GRB071010b: optical observation
- Swift XRT and UVOT observations of GRB071028B
- GRB071101: Optical and NIR upper limits by KANATA
- GRB 071101: TAROT Calern observatory optical observations
- GRB 071101: BOOTES-2 prompt optical observations
- GRB 071020: MITSuME Akeno optical observations
- GRB 071031: REM NIR and Optical observation
- GRB 071031, SMARTS afterglow observations
- GRB 071031: VLT high-resolution spectroscopy
- GRB 071031: Swift detection of a burst with an optical counterpart
- GRB071025: Optical+NIR observations
- Swift UVOT upper limits to GRB071028
- GRB 071025: Kuiper Telescope Optical Observations
- GRB 071018: Revised BAT position
- GRB 071025A: RAPTOR Observations of Complex Early Optical Behavior
- GRB071021: MARGE Optical Limits
- GRB071020, optical upper limit
- GRB071025: Optical Pre-imaging from Palomar
- GRB 071025: Swift-XRT Team refined analysis
- GRB 071025: ROTSE-III Refined Analysis
- GRB 071025: Swift XRT refined position
- GRB 071025: ROTSE-III Detection of Optical Counterpart
- GRB 071021: R-band detection and analysis
- GRB 071020: BTA spectroscopy
- GRB071021: Optical+NIR observations
- Optical observations of GRB 071020
- GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy