A transient/ variable system may be reported to the community through:

• Transient Name Server (TNS)
• Astronomers Telegrams (ATels)
• General Coordinates Network (GCNs; predominantly for GRB/ neutrino/ GW alerts)

and you can subscribe to these to get email updates about potential new sources worthy of follow-up. Alternatively, you may develop custom tools to identify interesting transients, such as through interacting with alert brokers (e.g. Lasair for ZTF allows for custom filtering scripts).

Visual inspection of the transient's position can be done through sky viewers (e.g. does the optical counterpart look like it's of Galactic origin?)

• Aladin
• Legacy DR10

We also want to include multi-wavelength information to further constrain the physical properties of the transient. To do this, we inspect the multi-wavelength time-series data available for the system. For optical:

• ASASSN (all-sky, but shallower)
• ATLAS (only down to -50)
• Gaia
• ZTF public lightcurves via ALeRCE / Lasair; ZTF forced photometry server

Mid-infrared:

• NEOWISE

X-ray:

• X-ray upper limit servers (provides a history of past X-ray detections): HILIGT
• Chandra: download via chaser interface
• NICER: download via HEASARC interface
• XMM: download via XMM science archive
• XRT: download via Swift XRT data centre, automated XRT image, spectra, lightcurve product generation

• Time domain astronomy taxonomy- what are the different types of transients?
• Caltech X-ray astronomy club lecture series